merge trunk

59 files changed, 1111 insertions, 902 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index c43404fa438..1040b93fe70 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,307 @@
+2012-08-28  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Do not allow to set major mode for a dead buffer.
+        * buffer.c (Fset_buffer_major_mode): Signal an error
+        if the buffer is dead.
+        (Fother_buffer, other_buffer_safely): Remove redundant
+        nested declaration.
+
+2012-08-28  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Always use set_buffer_if_live to restore original buffer at unwind.
+        * buffer.h (record_unwind_current_buffer): New function.
+        * bytecode.c, dispnew.c, editfns.c, fileio.c, fns.c, insdel.c:
+        * keyboard.c, keymap.c, minibuf.c, print.c, process.c, textprop.c:
+        * undo.c, window.c: Adjust users.
+        * buffer.c (set_buffer_if_live): Fix comment.
+
+2012-08-28  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Fix usage of set_buffer_internal.
+        * buffer.h (set_buffer_internal): Make it BUFFER_INLINE.
+        * buffer.c (set_buffer_if_live): Use set_buffer_internal.
+        * coding.c (decode_coding): Omit redundant test.
+        * fileio.c (decide_coding_unwind): Likewise.
+        * fns.c (secure_hash): Likewise.
+        * insdel.c (modify_region): Likewise.
+        * keyboard.c (command_loop_1): Likewise.
+        * print.c (PRINTFINISH): Likewise.
+        * xdisp.c (run_window_scroll_functions): Use set_buffer_internal.
+
+2012-08-27  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * dispnew.c: Use bool for boolean.
+        (frame_garbaged, display_completed, delayed_size_change)
+        (fonts_changed_p, add_window_display_history)
+        (add_frame_display_history, verify_row_hash)
+        (adjust_glyph_matrix, clear_window_matrices, glyph_row_slice_p)
+        (row_equal_p, realloc_glyph_pool)
+        (allocate_matrices_for_frame_redisplay)
+        (showing_window_margins_p)
+        (adjust_frame_glyphs_for_frame_redisplay)
+        (build_frame_matrix_from_leaf_window, make_current)
+        (mirrored_line_dance, mirror_line_dance, update_frame)
+        (update_window_tree, update_single_window)
+        (check_current_matrix_flags, update_window, update_text_area)
+        (update_window_line, set_window_update_flags, scrolling_window)
+        (update_frame_1, scrolling, buffer_posn_from_coords)
+        (do_pending_window_change, change_frame_size)
+        (change_frame_size_1, sit_for):
+        Use bool for boolean.
+        (clear_glyph_matrix_rows): Rename from enable_glyph_matrix_rows,
+        and remove last int (actually boolean) argument, which was always 0.
+        All callers changed.
+        * dispextern.h, frame.h, lisp.h: Reflect above API changes.
+        * dispextern.h (struct composition_it): Use bool for boolean.
+        (struct glyph_matrix): Don't assume buffer sizes can fit in 'int'.
+        (struct bidi_it): Use unsigned:1, not int, for boolean prev_was_pdf.
+        * dired.c (file_name_completion):
+        Use bool for boolean.  (This was missed in an earlier change.)
+
+2012-08-27  Martin Rudalics  <rudalics@gmx.at>
+
+        * window.c (Fset_window_configuration): Revert first part of
+        last change.
+
+2012-08-27  Jan Djärv  <jan.h.d@swipnet.se>
+
+        * nsterm.h (NSPanel): New class variable dialog_return.
+
+        * nsmenu.m (initWithContentRect:styleMask:backing:defer:): Initialize
+        dialog_return.
+        (windowShouldClose:): Use stop instead of stopModalWithCode.
+        (clicked:): Ditto, and also set dialog_return (Bug#12258).
+        (timeout_handler:): Use stop instead of abortModal.  Send a dummy
+        event.
+        (runDialogAt:): Make ret Lisp_Object.  Set it from dialog_return when
+        modal loop returns.
+
+2012-08-27  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * composite.c, data.c, dbusbind.c, dired.c: Use bool for booleans.
+        * composite.c (find_composition, composition_gstring_p)
+        (composition_reseat_it, find_automatic_composition):
+        * data.c (let_shadows_buffer_binding_p)
+        (let_shadows_global_binding_p, set_internal, make_blv)
+        (Fmake_variable_buffer_local, Fmake_local_variable)
+        (Fmake_variable_frame_local, arithcompare, cons_to_unsigned)
+        (cons_to_signed, arith_driver):
+        * dbusbind.c (xd_in_read_queued_messages):
+        * dired.c (directory_files_internal, file_name_completion):
+        Use bool for booleans.
+        * dired.c (file_name_completion):
+        * process.h (fd_callback):
+        Omit int (actually boolean) argument.  It wasn't being used.
+        All uses changed.
+        * composite.h, lisp.h: Reflect above API changes.
+
+        * cmds.c, coding.c: Use bool for booleans.
+        * cmds.c (move_point, Fself_insert_command):
+        * coding.h (struct composition status, struct coding_system):
+        * coding.c (detect_coding_utf_8, encode_coding_utf_8)
+        (detect_coding_utf_16, encode_coding_utf_16, detect_coding_emacs_mule)
+        (emacs_mule_char, decode_coding_emacs_mule)
+        (encode_coding_emacs_mule, detect_coding_iso_2022)
+        (decode_coding_iso_2022, encode_invocation_designation)
+        (encode_designation_at_bol, encode_coding_iso_2022)
+        (detect_coding_sjis, detect_coding_big5, decode_coding_sjis)
+        (decode_coding_big5, encode_coding_sjis, encode_coding_big5)
+        (detect_coding_ccl, encode_coding_ccl, decode_coding_raw_text)
+        (encode_coding_raw_text, detect_coding_charset)
+        (decode_coding_charset, encode_coding_charset, detect_eol)
+        (detect_coding, get_translation_table, produce_chars)
+        (consume_chars, reused_workbuf_in_use)
+        (make_conversion_work_buffer, code_conversion_save)
+        (decode_coding_object, encode_coding_object)
+        (detect_coding_system, char_encodable_p)
+        (Funencodable_char_position, code_convert_region)
+        (code_convert_string, code_convert_string_norecord)
+        (Fset_coding_system_priority):
+        * fileio.c (Finsert_file_contents):
+        Use bool for booleans.
+        * coding.h, lisp.h: Reflect above API changes.
+        * coding.c: Remove unnecessary static function decls.
+        (detect_coding): Use unsigned, not signed, to copy an unsigned field.
+        (decode_coding, encode_coding, decode_coding_gap): Return 'void',
+        not a boolean 'int', since callers never look at the return value.
+        (ALLOC_CONVERSION_WORK_AREA): Assume caller returns 'void', not 'int'.
+        * coding.h (decoding_buffer_size, encoding_buffer_size)
+        (emacs_mule_string_char): Remove unused extern decls.
+        (struct iso_2022_spec, struct coding_system):
+        Use 'unsigned int : 1' for boolean fields, since there's more than one.
+        (struct emacs_mule_spec): Remove unused field 'full_support'.
+        All initializations removed.
+        * cmds.c (internal_self_insert): Don't assume EMACS_INT fits in 'int'.
+
+2012-08-27  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Fix spare memory change (Bug#12286).
+        * alloc.c (mark_maybe_pointer): Handle MEM_TYPE_SPARE.
+        (valid_lisp_object_p): Likewise.
+
+2012-08-27  Martin Rudalics  <rudalics@gmx.at>
+
+        * window.c (Fset_window_configuration): Record any window's old
+        buffer if it's replaced (see Bug#8789).  If the new current
+        buffer doesn't appear in the selected window, go to its old
+        point (Bug#12208).
+
+2012-08-27  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Special MEM_TYPE_SPARE to denote reserved memory.
+        * alloc.c (enum mem_type): New memory type.
+        (refill_memory_reserve): Use new type for spare memory.
+        This prevents live_cons_p and live_string_p from incorrect
+        detection of uninitialized objects from spare memory as live.
+
+2012-08-26  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Spelling fixes.
+        * Makefile.in (.PHONY): versioclean -> versionclean.
+
+        Remove unused external symbols.
+        * data.c (Qcons, Qfloat, Qmisc, Qstring, Qvector):
+        * window.c (Qwindow_valid_p, decode_valid_window):
+        Now static, not extern.
+        * data.c (Qinterval): Remove; unused.
+        (syms_of_data): Do not define 'interval'.
+        * lisp.h (Qinteger, Qstring, Qmisc, Qvector, Qfloat, Qcons):
+        * window.h (decode_valid_window):
+        Remove decls.
+
+        * character.c, charset.c, chartab.c: Use bool for booleans.
+        * character.c (lisp_string_width, string_count_byte8)
+        (string_escape_byte8):
+        * charset.c (charset_map_loaded, load_charset_map, read_hex):
+        (load_charset_map_from_file, map_charset_chars)
+        (Fdefine_charset_internal, define_charset_internal)
+        (Fdeclare_equiv_charset, find_charsets_in_text)
+        (Ffind_charset_region, char_charset, Fiso_charset):
+        * chartab.c (sub_char_table_ref, sub_char_table_ref_and_range)
+        (sub_char_table_set, sub_char_table_set_range)
+        (char_table_set_range, optimize_sub_char_table)
+        (map_sub_char_table):
+        Use bool for boolean.
+        * character.c (str_to_unibyte): Omit last boolean argument; it was
+        always 0.  All callers changed.
+        * character.h, charset.h: Adjust to match previous changes.
+        * character.h (char_printable_p): Remove decl of nonexistent function.
+        * charset.h (struct charset): Members code_linear_p, iso_chars_96,
+        ascii_compatible_p, supplementary_p, compact_codes_p, unified_p
+        are all boolean, so make them single-bit bitfields.
+
+        * lisp.h (ASET): Remove attempt to detect side effects.
+        It was meant to be temporary and it often doesn't work,
+        because when IDX has side effects the behavior of IDX==IDX
+        is undefined.  See Stefan Monnier in
+        <http://lists.gnu.org/archive/html/emacs-devel/2012-08/msg00762.html>.
+
+2012-08-26  Barry OReilly  <gundaetiapo@gmail.com>  (tiny change)
+
+        * lisp.h (functionp): New function (extracted from Ffunctionp).
+        (FUNCTIONP): Use it.
+        * eval.c (Ffunctionp): Use it.
+
+2012-08-25  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * xgselect.c (xg_select): Use auto storage for the GPollFD buffer
+        as that's faster and simpler than static storage.  Don't bother
+        with the g_main_context_query overhead if g_main_context_pending
+        says no events are pending.
+        (gfds, gfds_size): Remove these static vars.
+        (xgselect_initialize): Remove; no longer needed.
+        All uses and decls removed.
+
+        * emacs.c (fatal_error_signal_hook): Remove.
+        All uses removed.  This leftover from old code was always 0.
+
+        * casefiddle.c, casetab.c, category.c: Use bool for boolean.
+        * casefiddle.c (casify_object, casify_region):
+        * casetab.c (set_case_table):
+        * category.c, category.h (word_boundary_p):
+        * category.h (CHAR_HAS_CATEGORY):
+        Use bool for booleans, instead of int.
+
+2012-08-25  Eli Zaretskii  <eliz@gnu.org>
+
+        * makefile.w32-in ($(BLD)/alloc.$(O)): Depend on $(GNU_LIB)/execinfo.h.
+
+2012-08-25  Paul Eggert  <eggert@cs.ucla.edu>
+
+        On assertion failure, print backtrace if available.
+        * alloc.c [ENABLE_CHECKING]: Include <execinfo.h>.
+        (die) [ENABLE_CHECKING]: Print a backtrace if available.
+        * Makefile.in (LIB_EXECINFO): New macro.
+        (LIBES): Use it.
+
+        * bytecode.c, callint.c, callproc.c: Use bool for boolean.
+        * bytecode.c (exec_byte_code):
+        * callint.c (check_mark, Fcall_interactively):
+        * callproc.c (Fcall_process, add_env, child_setup, getenv_internal_1)
+        (getenv_internal, sync_process_alive, call_process_exited):
+        * lisp.h (USE_SAFE_ALLOCA):
+        Use bool for booleans, instead of int.
+        * lisp.h, process.h: Adjust prototypes to match above changes.
+        * callint.c (Fcall_interactively): Don't assume the mark's
+        offset fits in 'int'.
+
+2012-08-24  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * buffer.c, buffer.h: Use bool for boolean.
+        * buffer.c (reset_buffer_local_variables)
+        (buffer_lisp_local_variables, Fset_buffer_modified_p)
+        (Frestore_buffer_modified_p, Fset_buffer_multibyte):
+        (overlays_at, overlays_in, mouse_face_overlay_overlaps)
+        (overlay_touches_p, overlay_strings, Foverlay_put)
+        (report_overlay_modification, call_overlay_mod_hooks):
+        (mmap_enlarge, mmap_set_vars):
+        * buffer.h (buffer_has_overlays, uppercasep, lowercasep):
+        Use bool for booleans, instead of int.
+        * buffer.c (compact_buffer, mmap_free_1): Return void, not int,
+        since the 1-or-0 return value is always ignored anyway.
+        (mmap_initialized_p):
+        * buffer.h (struct buffer_text.inhibit_shrinking): Now bool, not int.
+        * buffer.h, lisp.h: Adjust prototypes to match above changes.
+
+2012-08-23  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * bidi.c: Use bool for boolean.
+        This is a bit more readable, and makes the text segment of bidi.o
+        0.4% smaller on my platform (GCC 4.7.1 x86-64, Fedora 15).
+        Presumably it's faster too.
+        (bidi_initialized, bidi_ignore_explicit_marks_for_paragraph_level):
+        Now bool.
+        (bidi_cache_find_level_change, bidi_cache_iterator_state)
+        (bidi_unshelve_cache, bidi_init_it, bidi_count_bytes)
+        (bidi_char_at_pos, bidi_fetch_char, bidi_paragraph_init)
+        (bidi_explicit_dir_char, bidi_level_of_next_char)
+        (bidi_find_other_level_edge, bidi_move_to_visually_next):
+        Use bool for booleans, instead of int.
+        * dispextern.h (bidi_init_it, bidi_paragraph_init)
+        (bidi_unshelve_cache): Adjust decls to match code.
+
+2012-08-23  Martin Rudalics  <rudalics@gmx.at>
+
+        * keyboard.c (Fposn_at_x_y): Do not allow internal window as
+        argument.
+
+2012-08-23  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * atimer.c, atimer.h (turn_on_atimers): Use bool for boolean.
+        * atimer.h: Include <stdbool.h>.
+
+2012-08-22  Dan Nicolaescu  <dann@gnu.org>
+
+        * frame.h (FRAME_W32_P, FRAME_MSDOS_P, FRAME_NS_P): Change to
+        compile time tests instead of run time tests on systems that do
+        not use them.
+        (FRAME_MAC_P): Remove leftover from deleted code.
+        * frame.c (syms_of_frame): Remove leftover from deleted code.
+
+2012-08-22  Jan Djärv  <jan.h.d@swipnet.se>
+
+        * nsterm.m (insertText:): Don't clear modifiers if code is space.
+
 2012-08-22  Paul Eggert  <eggert@cs.ucla.edu>
 
         * fontset.c (FONTSET_ADD): Return void, not Lisp_Object.
@@ -60,8 +364,8 @@
         * w32uniscribe.c (uniscribe_shape): Fix producing gstring
         components for RTL text (Bug#11860).  Adjust X-OFFSET of each
         non-base glyph for the width of the base character, according to
-        what x_draw_composite_glyph_string_foreground expects.  Generate
-        WADJUST value according to composition_gstring_width's
+        what x_draw_composite_glyph_string_foreground expects.
+        Generate WADJUST value according to composition_gstring_width's
         expectations, to produce correct width of the composed character.
         Reverse the sign of the DU offset produced by ScriptPlace.
 
diff --git a/src/Makefile.in b/src/Makefile.in
index 1d89af31401..60df1f1c677 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -159,6 +159,8 @@ DBUS_LIBS = @DBUS_LIBS@
 ## dbusbind.o if HAVE_DBUS, else empty.
 DBUS_OBJ = @DBUS_OBJ@
 
+LIB_EXECINFO=@LIB_EXECINFO@
+
 SETTINGS_CFLAGS = @SETTINGS_CFLAGS@
 SETTINGS_LIBS = @SETTINGS_LIBS@
 
@@ -383,6 +385,7 @@ otherobj= $(TERMCAP_OBJ) $(PRE_ALLOC_OBJ) $(GMALLOC_OBJ) $(RALLOC_OBJ) \
 ## with GCC, we might need LIB_GCC again after them.
 LIBES = $(LIBS) $(LIBX_BASE) $(LIBX_OTHER) $(LIBSOUND) \
    $(RSVG_LIBS) $(IMAGEMAGICK_LIBS) $(LIB_CLOCK_GETTIME) $(DBUS_LIBS) \
+   $(LIB_EXECINFO) \
    $(LIBXML2_LIBS) $(LIBGPM) $(LIBRESOLV) $(LIBS_SYSTEM) \
    $(LIBS_TERMCAP) $(GETLOADAVG_LIBS) $(SETTINGS_LIBS) $(LIBSELINUX_LIBS) \
    $(FREETYPE_LIBS) $(FONTCONFIG_LIBS) $(LIBOTF_LIBS) $(M17N_FLT_LIBS) \
@@ -499,7 +502,7 @@ doc.o: buildobj.h
 @ns_frag@
 
 .PHONY: mostlyclean clean bootstrap-clean distclean maintainer-clean
-.PHONY: versioclean extraclean frc
+.PHONY: versionclean extraclean frc
 
 mostlyclean:
         rm -f temacs$(EXEEXT) core *.core \#* *.o libXMenu11.a liblw.a
diff --git a/src/alloc.c b/src/alloc.c
index f0da9416ece..36ba22cc535 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -305,7 +305,9 @@ enum mem_type
      and runtime slowdown.  Minor but pointless.  */
   MEM_TYPE_VECTORLIKE,
   /* Special type to denote vector blocks.  */
-  MEM_TYPE_VECTOR_BLOCK
+  MEM_TYPE_VECTOR_BLOCK,
+  /* Special type to denote reserved memory.  */
+  MEM_TYPE_SPARE
 };
 
 static void *lisp_malloc (size_t, enum mem_type);
@@ -3816,22 +3818,22 @@ refill_memory_reserve (void)
     spare_memory[0] = malloc (SPARE_MEMORY);
   if (spare_memory[1] == 0)
     spare_memory[1] = lisp_align_malloc (sizeof (struct cons_block),
-                                                  MEM_TYPE_CONS);
+                                                  MEM_TYPE_SPARE);
   if (spare_memory[2] == 0)
     spare_memory[2] = lisp_align_malloc (sizeof (struct cons_block),
-                                         MEM_TYPE_CONS);
+                                         MEM_TYPE_SPARE);
   if (spare_memory[3] == 0)
     spare_memory[3] = lisp_align_malloc (sizeof (struct cons_block),
-                                         MEM_TYPE_CONS);
+                                         MEM_TYPE_SPARE);
   if (spare_memory[4] == 0)
     spare_memory[4] = lisp_align_malloc (sizeof (struct cons_block),
-                                         MEM_TYPE_CONS);
+                                         MEM_TYPE_SPARE);
   if (spare_memory[5] == 0)
     spare_memory[5] = lisp_malloc (sizeof (struct string_block),
-                                   MEM_TYPE_STRING);
+                                   MEM_TYPE_SPARE);
   if (spare_memory[6] == 0)
     spare_memory[6] = lisp_malloc (sizeof (struct string_block),
-                                   MEM_TYPE_STRING);
+                                   MEM_TYPE_SPARE);
   if (spare_memory[0] && spare_memory[1] && spare_memory[5])
     Vmemory_full = Qnil;
 #endif
@@ -4561,6 +4563,7 @@ mark_maybe_pointer (void *p)
       switch (m->type)
         {
         case MEM_TYPE_NON_LISP:
+        case MEM_TYPE_SPARE:
           /* Nothing to do; not a pointer to Lisp memory.  */
           break;
 
@@ -5017,6 +5020,7 @@ valid_lisp_object_p (Lisp_Object obj)
   switch (m->type)
     {
     case MEM_TYPE_NON_LISP:
+    case MEM_TYPE_SPARE:
       return 0;
 
     case MEM_TYPE_BUFFER:
@@ -6681,13 +6685,21 @@ which_symbols (Lisp_Object obj, EMACS_INT find_max)
 }
 
 #ifdef ENABLE_CHECKING
+
+# include <execinfo.h>
+
 bool suppress_checking;
 
 void
 die (const char *msg, const char *file, int line)
 {
+  enum { NPOINTERS_MAX = 500 };
+  void *buffer[NPOINTERS_MAX];
+  int npointers;
   fprintf (stderr, "\r\n%s:%d: Emacs fatal error: %s\r\n",
            file, line, msg);
+  npointers = backtrace (buffer, NPOINTERS_MAX);
+  backtrace_symbols_fd (buffer, npointers, STDERR_FILENO);
   abort ();
 }
 #endif
diff --git a/src/atimer.c b/src/atimer.c
index d67e1375f9a..eb3136ae55d 100644
--- a/src/atimer.c
+++ b/src/atimer.c
@@ -408,7 +408,7 @@ do_pending_atimers (void)
    some systems like HPUX (see process.c).  */
 
 void
-turn_on_atimers (int on)
+turn_on_atimers (bool on)
 {
   if (on)
     {
diff --git a/src/atimer.h b/src/atimer.h
index 4282bab49ba..6d441d71641 100644
--- a/src/atimer.h
+++ b/src/atimer.h
@@ -20,6 +20,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define EMACS_ATIMER_H
 
 #include "systime.h"            /* for EMACS_TIME */
+#include <stdbool.h>
 
 /* Forward declaration.  */
 
@@ -74,7 +75,7 @@ struct atimer *start_atimer (enum atimer_type, EMACS_TIME,
 void cancel_atimer (struct atimer *);
 void do_pending_atimers (void);
 void init_atimer (void);
-void turn_on_atimers (int);
+void turn_on_atimers (bool);
 void stop_other_atimers (struct atimer *);
 Lisp_Object unwind_stop_other_atimers (Lisp_Object);
 
diff --git a/src/bidi.c b/src/bidi.c
index 4df585d4f48..6b3ac53d318 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -63,7 +63,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "buffer.h"
 #include "dispextern.h"
 
-static int bidi_initialized = 0;
+static bool bidi_initialized = 0;
 
 static Lisp_Object bidi_type_table, bidi_mirror_table;
 
@@ -82,10 +82,10 @@ typedef enum {
 /* UAX#9 says to search only for L, AL, or R types of characters, and
    ignore RLE, RLO, LRE, and LRO, when determining the base paragraph
    level.  Yudit indeed ignores them.  This variable is therefore set
-   by default to ignore them, but setting it to zero will take them
-   into account.  */
-extern int bidi_ignore_explicit_marks_for_paragraph_level EXTERNALLY_VISIBLE;
-int bidi_ignore_explicit_marks_for_paragraph_level = 1;
+   by default to ignore them, but clearing it will take them into
+   account.  */
+extern bool bidi_ignore_explicit_marks_for_paragraph_level EXTERNALLY_VISIBLE;
+bool bidi_ignore_explicit_marks_for_paragraph_level = 1;
 
 static Lisp_Object paragraph_start_re, paragraph_separate_re;
 static Lisp_Object Qparagraph_start, Qparagraph_separate;
@@ -438,7 +438,7 @@ bidi_cache_search (ptrdiff_t charpos, int level, int dir)
    that is lower than LEVEL, and return its cache slot index.  DIR is
    the direction to search, starting with the last used cache slot.
    If DIR is zero, we search backwards from the last occupied cache
-   slot.  BEFORE, if non-zero, means return the index of the slot that
+   slot.  BEFORE means return the index of the slot that
    is ``before'' the level change in the search direction.  That is,
    given the cached levels like this:
 
@@ -448,9 +448,9 @@ bidi_cache_search (ptrdiff_t charpos, int level, int dir)
    and assuming we are at the position cached at the slot marked with
    C, searching backwards (DIR = -1) for LEVEL = 2 will return the
    index of slot B or A, depending whether BEFORE is, respectively,
-   non-zero or zero.  */
+   true or false.  */
 static ptrdiff_t
-bidi_cache_find_level_change (int level, int dir, int before)
+bidi_cache_find_level_change (int level, int dir, bool before)
 {
   if (bidi_cache_idx)
     {
@@ -512,7 +512,7 @@ bidi_cache_ensure_space (ptrdiff_t idx)
 }
 
 static inline void
-bidi_cache_iterator_state (struct bidi_it *bidi_it, int resolved)
+bidi_cache_iterator_state (struct bidi_it *bidi_it, bool resolved)
 {
   ptrdiff_t idx;
 
@@ -690,11 +690,11 @@ bidi_shelve_cache (void)
 
 /* Restore the cache state from a copy stashed away by
    bidi_shelve_cache, and free the buffer used to stash that copy.
-   JUST_FREE non-zero means free the buffer, but don't restore the
+   JUST_FREE means free the buffer, but don't restore the
    cache; used when the corresponding iterator is discarded instead of
    being restored.  */
 void
-bidi_unshelve_cache (void *databuf, int just_free)
+bidi_unshelve_cache (void *databuf, bool just_free)
 {
   unsigned char *p = databuf;
 
@@ -802,7 +802,7 @@ bidi_set_paragraph_end (struct bidi_it *bidi_it)
 
 /* Initialize the bidi iterator from buffer/string position CHARPOS.  */
 void
-bidi_init_it (ptrdiff_t charpos, ptrdiff_t bytepos, int frame_window_p,
+bidi_init_it (ptrdiff_t charpos, ptrdiff_t bytepos, bool frame_window_p,
               struct bidi_it *bidi_it)
 {
   if (! bidi_initialized)
@@ -872,11 +872,10 @@ bidi_line_init (struct bidi_it *bidi_it)
 
 /* Count bytes in string S between BEG/BEGBYTE and END.  BEG and END
    are zero-based character positions in S, BEGBYTE is byte position
-   corresponding to BEG.  UNIBYTE, if non-zero, means S is a unibyte
-   string.  */
+   corresponding to BEG.  UNIBYTE means S is a unibyte string.  */
 static inline ptrdiff_t
 bidi_count_bytes (const unsigned char *s, const ptrdiff_t beg,
-                  const ptrdiff_t begbyte, const ptrdiff_t end, int unibyte)
+                  const ptrdiff_t begbyte, const ptrdiff_t end, bool unibyte)
 {
   ptrdiff_t pos = beg;
   const unsigned char *p = s + begbyte, *start = p;
@@ -900,10 +899,10 @@ bidi_count_bytes (const unsigned char *s, const ptrdiff_t beg,
 
 /* Fetch and returns the character at byte position BYTEPOS.  If S is
    non-NULL, fetch the character from string S; otherwise fetch the
-   character from the current buffer.  UNIBYTE non-zero means S is a
+   character from the current buffer.  UNIBYTE means S is a
    unibyte string.  */
 static inline int
-bidi_char_at_pos (ptrdiff_t bytepos, const unsigned char *s, int unibyte)
+bidi_char_at_pos (ptrdiff_t bytepos, const unsigned char *s, bool unibyte)
 {
   if (s)
     {
@@ -923,9 +922,9 @@ bidi_char_at_pos (ptrdiff_t bytepos, const unsigned char *s, int unibyte)
    specifies the character position of the next display string, or -1
    if not yet computed.  When the next character is at or beyond that
    position, the function updates DISP_POS with the position of the
-   next display string.  DISP_PROP non-zero means that there's really
+   next display string.  *DISP_PROP non-zero means that there's really
    a display string at DISP_POS, as opposed to when we searched till
-   DISP_POS without finding one.  If DISP_PROP is 2, it means the
+   DISP_POS without finding one.  If *DISP_PROP is 2, it means the
    display spec is of the form `(space ...)', which is replaced with
    u+2029 to handle it as a paragraph separator.  STRING->s is the C
    string to iterate, or NULL if iterating over a buffer or a Lisp
@@ -933,7 +932,7 @@ bidi_char_at_pos (ptrdiff_t bytepos, const unsigned char *s, int unibyte)
 static inline int
 bidi_fetch_char (ptrdiff_t bytepos, ptrdiff_t charpos, ptrdiff_t *disp_pos,
                  int *disp_prop, struct bidi_string_data *string,
-                 int frame_window_p, ptrdiff_t *ch_len, ptrdiff_t *nchars)
+                 bool frame_window_p, ptrdiff_t *ch_len, ptrdiff_t *nchars)
 {
   int ch;
   ptrdiff_t endpos
@@ -1134,7 +1133,7 @@ bidi_find_paragraph_start (ptrdiff_t pos, ptrdiff_t pos_byte)
    R2L, just use that.  Otherwise, determine the paragraph direction
    from the first strong directional character of the paragraph.
 
-   NO_DEFAULT_P non-zero means don't default to L2R if the paragraph
+   NO_DEFAULT_P means don't default to L2R if the paragraph
    has no strong directional characters and both DIR and
    bidi_it->paragraph_dir are NEUTRAL_DIR.  In that case, search back
    in the buffer until a paragraph is found with a strong character,
@@ -1145,10 +1144,10 @@ bidi_find_paragraph_start (ptrdiff_t pos, ptrdiff_t pos_byte)
    direction as the preceding paragraph, even though Emacs generally
    views the separator as not belonging to any paragraph.  */
 void
-bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, int no_default_p)
+bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, bool no_default_p)
 {
   ptrdiff_t bytepos = bidi_it->bytepos;
-  int string_p = bidi_it->string.s != NULL || STRINGP (bidi_it->string.lstring);
+  bool string_p = bidi_it->string.s || STRINGP (bidi_it->string.lstring);
   ptrdiff_t pstartbyte;
   /* Note that begbyte is a byte position, while end is a character
      position.  Yes, this is ugly, but we are trying to avoid costly
@@ -1221,8 +1220,8 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, int no_default_p)
       bidi_it->separator_limit = -1;
       bidi_it->new_paragraph = 0;
 
-      /* The following loop is run more than once only if NO_DEFAULT_P
-         is non-zero, and only if we are iterating on a buffer.  */
+      /* The following loop is run more than once only if NO_DEFAULT_P,
+         and only if we are iterating on a buffer.  */
       do {
         ptrdiff_t pos1;
 
@@ -1320,7 +1319,7 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, int no_default_p)
   The rest of this file constitutes the core of the UBA implementation.
  ***********************************************************************/
 
-static inline int
+static inline bool
 bidi_explicit_dir_char (int ch)
 {
   bidi_type_t ch_type;
@@ -1345,7 +1344,7 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
   int current_level;
   int new_level;
   bidi_dir_t override;
-  int string_p = bidi_it->string.s != NULL || STRINGP (bidi_it->string.lstring);
+  bool string_p = bidi_it->string.s || STRINGP (bidi_it->string.lstring);
 
   /* If reseat()'ed, don't advance, so as to start iteration from the
      position where we were reseated.  bidi_it->bytepos can be less
@@ -2189,7 +2188,7 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
       ptrdiff_t nc = bidi_it->nchars;
       struct bidi_string_data bs = bidi_it->string;
       bidi_type_t chtype;
-      int fwp = bidi_it->frame_window_p;
+      bool fwp = bidi_it->frame_window_p;
       int dpp = bidi_it->disp_prop;
 
       if (bidi_it->nchars <= 0)
@@ -2268,8 +2267,8 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
   return level;
 }
 
-/* Move to the other edge of a level given by LEVEL.  If END_FLAG is
-   non-zero, we are at the end of a level, and we need to prepare to
+/* Move to the other edge of a level given by LEVEL.  If END_FLAG,
+   we are at the end of a level, and we need to prepare to
    resume the scan of the lower level.
 
    If this level's other edge is cached, we simply jump to it, filling
@@ -2289,7 +2288,7 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
    function moves to point C, whereas the UAX#9 ``level 2 run'' ends
    at point B.  */
 static void
-bidi_find_other_level_edge (struct bidi_it *bidi_it, int level, int end_flag)
+bidi_find_other_level_edge (struct bidi_it *bidi_it, int level, bool end_flag)
 {
   int dir = end_flag ? -bidi_it->scan_dir : bidi_it->scan_dir;
   ptrdiff_t idx;
@@ -2363,7 +2362,7 @@ bidi_move_to_visually_next (struct bidi_it *bidi_it)
      scanning the text whenever we find a level change.  */
   if (new_level != old_level)
     {
-      int ascending = new_level > old_level;
+      bool ascending = new_level > old_level;
       int level_to_search = ascending ? old_level + 1 : old_level;
       int incr = ascending ? 1 : -1;
       int expected_next_level = old_level + incr;
diff --git a/src/buffer.c b/src/buffer.c
index c900ef8c5a8..0e2e50d9f51 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -110,10 +110,10 @@ static char buffer_permanent_local_flags[MAX_PER_BUFFER_VARS];
 int last_per_buffer_idx;
 
 static void call_overlay_mod_hooks (Lisp_Object list, Lisp_Object overlay,
-                                    int after, Lisp_Object arg1,
+                                    bool after, Lisp_Object arg1,
                                     Lisp_Object arg2, Lisp_Object arg3);
 static void swap_out_buffer_local_variables (struct buffer *b);
-static void reset_buffer_local_variables (struct buffer *b, int permanent_too);
+static void reset_buffer_local_variables (struct buffer *, bool);
 
 /* Alist of all buffer names vs the buffers. */
 /* This used to be a variable, but is no longer,
@@ -155,7 +155,7 @@ static void alloc_buffer_text (struct buffer *, ptrdiff_t);
 static void free_buffer_text (struct buffer *b);
 static struct Lisp_Overlay * copy_overlays (struct buffer *, struct Lisp_Overlay *);
 static void modify_overlay (struct buffer *, ptrdiff_t, ptrdiff_t);
-static Lisp_Object buffer_lisp_local_variables (struct buffer *, int);
+static Lisp_Object buffer_lisp_local_variables (struct buffer *, bool);
 
 /* These setters are used only in this file, so they can be private.  */
 static inline void
@@ -979,15 +979,13 @@ reset_buffer (register struct buffer *b)
    it does not treat permanent locals consistently.
    Instead, use Fkill_all_local_variables.
 
-   If PERMANENT_TOO is 1, then we reset permanent
-   buffer-local variables.  If PERMANENT_TOO is 0,
-   we preserve those.  */
+   If PERMANENT_TOO, reset permanent buffer-local variables.
+   If not, preserve those.  */
 
 static void
-reset_buffer_local_variables (register struct buffer *b, int permanent_too)
+reset_buffer_local_variables (struct buffer *b, bool permanent_too)
 {
-  register int offset;
-  int i;
+  int offset, i;
 
   /* Reset the major mode to Fundamental, together with all the
      things that depend on the major mode.
@@ -1253,14 +1251,14 @@ buffer_local_value_1 (Lisp_Object variable, Lisp_Object buffer)
 /* Return an alist of the Lisp-level buffer-local bindings of
    buffer BUF.  That is, don't include the variables maintained
    in special slots in the buffer object.
-   If CLONE is zero elements of the form (VAR . unbound) are replaced
+   If not CLONE, replace elements of the form (VAR . unbound)
    by VAR.  */
 
 static Lisp_Object
-buffer_lisp_local_variables (struct buffer *buf, int clone)
+buffer_lisp_local_variables (struct buffer *buf, bool clone)
 {
   Lisp_Object result = Qnil;
-  register Lisp_Object tail;
+  Lisp_Object tail;
   for (tail = BVAR (buf, local_var_alist); CONSP (tail); tail = XCDR (tail))
     {
       Lisp_Object val, elt;
@@ -1351,11 +1349,9 @@ DEFUN ("set-buffer-modified-p", Fset_buffer_modified_p, Sset_buffer_modified_p,
        1, 1, 0,
        doc: /* Mark current buffer as modified or unmodified according to FLAG.
 A non-nil FLAG means mark the buffer modified.  */)
-  (register Lisp_Object flag)
+  (Lisp_Object flag)
 {
-  register int already;
-  register Lisp_Object fn;
-  Lisp_Object buffer, window;
+  Lisp_Object fn, buffer, window;
 
 #ifdef CLASH_DETECTION
   /* If buffer becoming modified, lock the file.
@@ -1365,7 +1361,7 @@ A non-nil FLAG means mark the buffer modified.  */)
   /* Test buffer-file-name so that binding it to nil is effective.  */
   if (!NILP (fn) && ! NILP (BVAR (current_buffer, filename)))
     {
-      already = SAVE_MODIFF < MODIFF;
+      bool already = SAVE_MODIFF < MODIFF;
       if (!already && !NILP (flag))
         lock_file (fn);
       else if (already && NILP (flag))
@@ -1432,7 +1428,7 @@ state of the current buffer.  Use with care.  */)
   /* Test buffer-file-name so that binding it to nil is effective.  */
   if (!NILP (fn) && ! NILP (BVAR (current_buffer, filename)))
     {
-      int already = SAVE_MODIFF < MODIFF;
+      bool already = SAVE_MODIFF < MODIFF;
       if (!already && !NILP (flag))
         lock_file (fn);
       else if (already && NILP (flag))
@@ -1557,7 +1553,6 @@ list first, followed by the list of all buffers.  If no other buffer
 exists, return the buffer `*scratch*' (creating it if necessary).  */)
   (register Lisp_Object buffer, Lisp_Object visible_ok, Lisp_Object frame)
 {
-  Lisp_Object Fset_buffer_major_mode (Lisp_Object buffer);
   Lisp_Object tail, buf, pred;
   Lisp_Object notsogood = Qnil;
 
@@ -1628,7 +1623,6 @@ exists, return the buffer `*scratch*' (creating it if necessary).  */)
 Lisp_Object
 other_buffer_safely (Lisp_Object buffer)
 {
-  Lisp_Object Fset_buffer_major_mode (Lisp_Object buffer);
   Lisp_Object tail, buf;
 
   tail = Vbuffer_alist;
@@ -1676,7 +1670,7 @@ No argument or nil as argument means do this for the current buffer.  */)
 
 /* Truncate undo list and shrink the gap of BUFFER.  */
 
-int
+void
 compact_buffer (struct buffer *buffer)
 {
   /* Verify indirection counters.  */
@@ -1718,9 +1712,7 @@ compact_buffer (struct buffer *buffer)
             }
         }
       buffer->text->compact = buffer->text->modiff;
-      return 1;
     }
-  return 0;
 }
 
 DEFUN ("kill-buffer", Fkill_buffer, Skill_buffer, 0, 1, "bKill buffer: ",
@@ -2070,8 +2062,10 @@ the current buffer's major mode.  */)
 
   CHECK_BUFFER (buffer);
 
-  if (STRINGP (BVAR (XBUFFER (buffer), name))
-      && strcmp (SSDATA (BVAR (XBUFFER (buffer), name)), "*scratch*") == 0)
+  if (NILP (BVAR (XBUFFER (buffer), name)))
+    error ("Attempt to set major mode for a dead buffer");
+
+  if (strcmp (SSDATA (BVAR (XBUFFER (buffer), name)), "*scratch*") == 0)
     function = find_symbol_value (intern ("initial-major-mode"));
   else
     {
@@ -2105,22 +2099,6 @@ DEFUN ("current-buffer", Fcurrent_buffer, Scurrent_buffer, 0, 0, 0,
   XSETBUFFER (buf, current_buffer);
   return buf;
 }
-
-/* Set the current buffer to B.
-
-   We previously set windows_or_buffers_changed here to invalidate
-   global unchanged information in beg_unchanged and end_unchanged.
-   This is no longer necessary because we now compute unchanged
-   information on a buffer-basis.  Every action affecting other
-   windows than the selected one requires a select_window at some
-   time, and that increments windows_or_buffers_changed.  */
-
-void
-set_buffer_internal (register struct buffer *b)
-{
-  if (current_buffer != b)
-    set_buffer_internal_1 (b);
-}
 
 /* Set the current buffer to B, and do not set windows_or_buffers_changed.
    This is used by redisplay.  */
@@ -2226,13 +2204,13 @@ ends when the current command terminates.  Use `switch-to-buffer' or
   return buffer;
 }
 
-/* Set the current buffer to BUFFER provided it is alive.  */
+/* Set the current buffer to BUFFER provided if it is alive.  */
 
 Lisp_Object
 set_buffer_if_live (Lisp_Object buffer)
 {
   if (! NILP (BVAR (XBUFFER (buffer), name)))
-    Fset_buffer (buffer);
+    set_buffer_internal (XBUFFER (buffer));
   return Qnil;
 }
 
@@ -2471,8 +2449,8 @@ current buffer is cleared.  */)
   struct Lisp_Marker *tail, *markers;
   struct buffer *other;
   ptrdiff_t begv, zv;
-  int narrowed = (BEG != BEGV || Z != ZV);
-  int modified_p = !NILP (Fbuffer_modified_p (Qnil));
+  bool narrowed = (BEG != BEGV || Z != ZV);
+  bool modified_p = !NILP (Fbuffer_modified_p (Qnil));
   Lisp_Object old_undo = BVAR (current_buffer, undo_list);
   struct gcpro gcpro1;
 
@@ -2821,19 +2799,19 @@ swap_out_buffer_local_variables (struct buffer *b)
    *VEC_PTR and *LEN_PTR should contain a valid vector and size
    when this function is called.
 
-   If EXTEND is non-zero, we make the vector bigger if necessary.
-   If EXTEND is zero, we never extend the vector,
-   and we store only as many overlays as will fit.
-   But we still return the total number of overlays.
+   If EXTEND, make the vector bigger if necessary.
+   If not, never extend the vector,
+   and store only as many overlays as will fit.
+   But still return the total number of overlays.
 
-   If CHANGE_REQ is true, then any position written into *PREV_PTR or
+   If CHANGE_REQ, any position written into *PREV_PTR or
    *NEXT_PTR is guaranteed to be not equal to POS, unless it is the
    default (BEGV or ZV).  */
 
 ptrdiff_t
-overlays_at (EMACS_INT pos, int extend, Lisp_Object **vec_ptr,
+overlays_at (EMACS_INT pos, bool extend, Lisp_Object **vec_ptr,
              ptrdiff_t *len_ptr,
-             ptrdiff_t *next_ptr, ptrdiff_t *prev_ptr, int change_req)
+             ptrdiff_t *next_ptr, ptrdiff_t *prev_ptr, bool change_req)
 {
   Lisp_Object overlay, start, end;
   struct Lisp_Overlay *tail;
@@ -2842,7 +2820,7 @@ overlays_at (EMACS_INT pos, int extend, Lisp_Object **vec_ptr,
   Lisp_Object *vec = *vec_ptr;
   ptrdiff_t next = ZV;
   ptrdiff_t prev = BEGV;
-  int inhibit_storing = 0;
+  bool inhibit_storing = 0;
 
   for (tail = current_buffer->overlays_before; tail; tail = tail->next)
     {
@@ -2959,13 +2937,13 @@ overlays_at (EMACS_INT pos, int extend, Lisp_Object **vec_ptr,
    *VEC_PTR and *LEN_PTR should contain a valid vector and size
    when this function is called.
 
-   If EXTEND is non-zero, we make the vector bigger if necessary.
-   If EXTEND is zero, we never extend the vector,
-   and we store only as many overlays as will fit.
-   But we still return the total number of overlays.  */
+   If EXTEND, make the vector bigger if necessary.
+   If not, never extend the vector,
+   and store only as many overlays as will fit.
+   But still return the total number of overlays.  */
 
 static ptrdiff_t
-overlays_in (EMACS_INT beg, EMACS_INT end, int extend,
+overlays_in (EMACS_INT beg, EMACS_INT end, bool extend,
              Lisp_Object **vec_ptr, ptrdiff_t *len_ptr,
              ptrdiff_t *next_ptr, ptrdiff_t *prev_ptr)
 {
@@ -2976,8 +2954,8 @@ overlays_in (EMACS_INT beg, EMACS_INT end, int extend,
   Lisp_Object *vec = *vec_ptr;
   ptrdiff_t next = ZV;
   ptrdiff_t prev = BEGV;
-  int inhibit_storing = 0;
-  int end_is_Z = end == Z;
+  bool inhibit_storing = 0;
+  bool end_is_Z = end == Z;
 
   for (tail = current_buffer->overlays_before; tail; tail = tail->next)
     {
@@ -3078,10 +3056,10 @@ overlays_in (EMACS_INT beg, EMACS_INT end, int extend,
 }
 
 
-/* Return non-zero if there exists an overlay with a non-nil
+/* Return true if there exists an overlay with a non-nil
    `mouse-face' property overlapping OVERLAY.  */
 
-int
+bool
 mouse_face_overlay_overlaps (Lisp_Object overlay)
 {
   ptrdiff_t start = OVERLAY_POSITION (OVERLAY_START (overlay));
@@ -3110,7 +3088,7 @@ mouse_face_overlay_overlaps (Lisp_Object overlay)
 
 
 /* Fast function to just test if we're at an overlay boundary.  */
-int
+bool
 overlay_touches_p (ptrdiff_t pos)
 {
   Lisp_Object overlay;
@@ -3327,7 +3305,7 @@ overlay_strings (ptrdiff_t pos, struct window *w, unsigned char **pstr)
   Lisp_Object overlay, window, str;
   struct Lisp_Overlay *ov;
   ptrdiff_t startpos, endpos;
-  int multibyte = ! NILP (BVAR (current_buffer, enable_multibyte_characters));
+  bool multibyte = ! NILP (BVAR (current_buffer, enable_multibyte_characters));
 
   overlay_heads.used = overlay_heads.bytes = 0;
   overlay_tails.used = overlay_tails.bytes = 0;
@@ -4321,7 +4299,7 @@ VALUE will be returned.*/)
   (Lisp_Object overlay, Lisp_Object prop, Lisp_Object value)
 {
   Lisp_Object tail, buffer;
-  int changed;
+  bool changed;
 
   CHECK_OVERLAY (overlay);
 
@@ -4396,7 +4374,7 @@ add_overlay_mod_hooklist (Lisp_Object functionlist, Lisp_Object overlay)
    and the insert-after-hooks of overlay ending at START.
 
    This is called both before and after the modification.
-   AFTER is nonzero when we call after the modification.
+   AFTER is true when we call after the modification.
 
    ARG1, ARG2, ARG3 are arguments to pass to the hook functions.
    When AFTER is nonzero, they are the start position,
@@ -4404,13 +4382,13 @@ add_overlay_mod_hooklist (Lisp_Object functionlist, Lisp_Object overlay)
    and the length of deleted or replaced old text.  */
 
 void
-report_overlay_modification (Lisp_Object start, Lisp_Object end, int after,
+report_overlay_modification (Lisp_Object start, Lisp_Object end, bool after,
                              Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3)
 {
   Lisp_Object prop, overlay;
   struct Lisp_Overlay *tail;
-  /* 1 if this change is an insertion.  */
-  int insertion = (after ? XFASTINT (arg3) == 0 : EQ (start, end));
+  /* True if this change is an insertion.  */
+  bool insertion = (after ? XFASTINT (arg3) == 0 : EQ (start, end));
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
 
   overlay = Qnil;
@@ -4530,7 +4508,7 @@ report_overlay_modification (Lisp_Object start, Lisp_Object end, int after,
 }
 
 static void
-call_overlay_mod_hooks (Lisp_Object list, Lisp_Object overlay, int after,
+call_overlay_mod_hooks (Lisp_Object list, Lisp_Object overlay, bool after,
                         Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3)
 {
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
@@ -4689,7 +4667,7 @@ static int mmap_page_size;
 
 /* 1 means mmap has been initialized.  */
 
-static int mmap_initialized_p;
+static bool mmap_initialized_p;
 
 /* Value is X rounded up to the next multiple of N.  */
 
@@ -4785,9 +4763,9 @@ mmap_find (void *start, void *end)
 
 
 /* Unmap a region.  P is a pointer to the start of the user-araa of
-   the region.  Value is non-zero if successful.  */
+   the region.  */
 
-static int
+static void
 mmap_free_1 (struct mmap_region *r)
 {
   if (r->next)
@@ -4798,24 +4776,19 @@ mmap_free_1 (struct mmap_region *r)
     mmap_regions = r->next;
 
   if (munmap (r, r->nbytes_mapped) == -1)
-    {
-      fprintf (stderr, "munmap: %s\n", emacs_strerror (errno));
-      return 0;
-    }
-
-  return 1;
+    fprintf (stderr, "munmap: %s\n", emacs_strerror (errno));
 }
 
 
 /* Enlarge region R by NPAGES pages.  NPAGES < 0 means shrink R.
-   Value is non-zero if successful.  */
+   Value is true if successful.  */
 
-static int
+static bool
 mmap_enlarge (struct mmap_region *r, int npages)
 {
   char *region_end = (char *) r + r->nbytes_mapped;
   size_t nbytes;
-  int success = 0;
+  bool success = 0;
 
   if (npages < 0)
     {
@@ -4865,17 +4838,16 @@ mmap_enlarge (struct mmap_region *r, int npages)
 }
 
 
-/* Set or reset variables holding references to mapped regions.  If
-   RESTORE_P is zero, set all variables to null.  If RESTORE_P is
-   non-zero, set all variables to the start of the user-areas
-   of mapped regions.
+/* Set or reset variables holding references to mapped regions.
+   If not RESTORE_P, set all variables to null.  If RESTORE_P, set all
+   variables to the start of the user-areas of mapped regions.
 
    This function is called from Fdump_emacs to ensure that the dumped
    Emacs doesn't contain references to memory that won't be mapped
    when Emacs starts.  */
 
 void
-mmap_set_vars (int restore_p)
+mmap_set_vars (bool restore_p)
 {
   struct mmap_region *r;
 
diff --git a/src/buffer.h b/src/buffer.h
index 6c63c52dc47..3acf1423816 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -471,7 +471,7 @@ struct buffer_text
     /* Usually 0.  Temporarily set to 1 in decode_coding_gap to
        prevent Fgarbage_collect from shrinking the gap and losing
        not-yet-decoded bytes.  */
-    int inhibit_shrinking;
+    bool inhibit_shrinking;
   };
 
 /* Most code should use this macro to access Lisp fields in struct buffer.  */
@@ -1006,23 +1006,46 @@ extern struct buffer buffer_local_symbols;
 
 extern void delete_all_overlays (struct buffer *);
 extern void reset_buffer (struct buffer *);
-extern int compact_buffer (struct buffer *);
+extern void compact_buffer (struct buffer *);
 extern void evaporate_overlays (ptrdiff_t);
-extern ptrdiff_t overlays_at (EMACS_INT pos, int extend, Lisp_Object **vec_ptr,
-                              ptrdiff_t *len_ptr, ptrdiff_t *next_ptr,
-                              ptrdiff_t *prev_ptr, int change_req);
+extern ptrdiff_t overlays_at (EMACS_INT, bool, Lisp_Object **,
+                              ptrdiff_t *, ptrdiff_t *, ptrdiff_t *, bool);
 extern ptrdiff_t sort_overlays (Lisp_Object *, ptrdiff_t, struct window *);
 extern void recenter_overlay_lists (struct buffer *, ptrdiff_t);
 extern ptrdiff_t overlay_strings (ptrdiff_t, struct window *, unsigned char **);
 extern void validate_region (Lisp_Object *, Lisp_Object *);
-extern void set_buffer_internal (struct buffer *);
 extern void set_buffer_internal_1 (struct buffer *);
 extern void set_buffer_temp (struct buffer *);
 extern Lisp_Object buffer_local_value_1 (Lisp_Object, Lisp_Object);
 extern void record_buffer (Lisp_Object);
 extern _Noreturn void buffer_slot_type_mismatch (Lisp_Object, int);
 extern void fix_overlays_before (struct buffer *, ptrdiff_t, ptrdiff_t);
-extern void mmap_set_vars (int);
+extern void mmap_set_vars (bool);
+
+/* Set the current buffer to B.
+
+   We previously set windows_or_buffers_changed here to invalidate
+   global unchanged information in beg_unchanged and end_unchanged.
+   This is no longer necessary because we now compute unchanged
+   information on a buffer-basis.  Every action affecting other
+   windows than the selected one requires a select_window at some
+   time, and that increments windows_or_buffers_changed.  */
+
+BUFFER_INLINE void
+set_buffer_internal (struct buffer *b)
+{
+  if (current_buffer != b)
+    set_buffer_internal_1 (b);
+}
+
+/* Arrange to go back to the original buffer after the next
+   call to unbind_to if the original buffer is still alive.  */
+
+BUFFER_INLINE void
+record_unwind_current_buffer (void)
+{
+  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
+}
 
 /* Get overlays at POSN into array OVERLAYS with NOVERLAYS elements.
    If NEXTP is non-NULL, return next overlay there.
@@ -1067,7 +1090,7 @@ set_buffer_intervals (struct buffer *b, INTERVAL i)
 
 /* Non-zero if current buffer has overlays.  */
 
-BUFFER_INLINE int
+BUFFER_INLINE bool
 buffer_has_overlays (void)
 {
   return current_buffer->overlays_before || current_buffer->overlays_after;
@@ -1243,7 +1266,7 @@ downcase (int c)
 }
 
 /* 1 if C is upper case.  */
-BUFFER_INLINE int uppercasep (int c) { return downcase (c) != c; }
+BUFFER_INLINE bool uppercasep (int c) { return downcase (c) != c; }
 
 /* Upcase a character C known to be not upper case.  */
 BUFFER_INLINE int
@@ -1255,8 +1278,11 @@ upcase1 (int c)
 }
 
 /* 1 if C is lower case.  */
-BUFFER_INLINE int lowercasep (int c)
-{ return !uppercasep (c) && upcase1 (c) != c; }
+BUFFER_INLINE bool
+lowercasep (int c)
+{
+  return !uppercasep (c) && upcase1 (c) != c;
+}
 
 /* Upcase a character C, or make no change if that cannot be done.  */
 BUFFER_INLINE int upcase (int c) { return uppercasep (c) ? c : upcase1 (c); }
diff --git a/src/bytecode.c b/src/bytecode.c
index 5ac8b4fa2bd..40729cbd453 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -553,7 +553,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
   if (INTEGERP (args_template))
     {
       ptrdiff_t at = XINT (args_template);
-      int rest = at & 128;
+      bool rest = (at & 128) != 0;
       int mandatory = at & 127;
       ptrdiff_t nonrest = at >> 8;
       eassert (mandatory <= nonrest);
@@ -1051,7 +1051,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 
         CASE (Bsave_current_buffer): /* Obsolete since ??.  */
         CASE (Bsave_current_buffer_1):
-          record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
+          record_unwind_current_buffer ();
           NEXT;
 
         CASE (Bsave_window_excursion): /* Obsolete since 24.1.  */
diff --git a/src/callint.c b/src/callint.c
index 36a59e812f2..b11545ddea2 100644
--- a/src/callint.c
+++ b/src/callint.c
@@ -150,7 +150,7 @@ static const char *callint_argfuns[]
     = {"", "point", "mark", "region-beginning", "region-end"};
 
 static void
-check_mark (int for_region)
+check_mark (bool for_region)
 {
   Lisp_Object tem;
   tem = Fmarker_buffer (BVAR (current_buffer, mark));
@@ -273,11 +273,11 @@ invoke it.  If KEYS is omitted or nil, the return value of
   signed char *varies;
 
   ptrdiff_t i, nargs;
-  int foo;
-  int arg_from_tty = 0;
+  ptrdiff_t mark;
+  bool arg_from_tty = 0;
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
   ptrdiff_t key_count;
-  int record_then_fail = 0;
+  bool record_then_fail = 0;
 
   Lisp_Object save_this_command, save_last_command;
   Lisp_Object save_this_original_command, save_real_this_command;
@@ -685,7 +685,7 @@ invoke it.  If KEYS is omitted or nil, the return value of
             goto have_prefix_arg;
         case 'n':               /* Read number from minibuffer.  */
           {
-            int first = 1;
+            bool first = 1;
             do
               {
                 Lisp_Object str;
@@ -726,11 +726,11 @@ invoke it.  If KEYS is omitted or nil, the return value of
           check_mark (1);
           set_marker_both (point_marker, Qnil, PT, PT_BYTE);
           /* visargs[i+1] = Qnil; */
-          foo = marker_position (BVAR (current_buffer, mark));
+          mark = marker_position (BVAR (current_buffer, mark));
           /* visargs[i] = Qnil; */
-          args[i] = PT < foo ? point_marker : BVAR (current_buffer, mark);
+          args[i] = PT < mark ? point_marker : BVAR (current_buffer, mark);
           varies[i] = 3;
-          args[++i] = PT > foo ? point_marker : BVAR (current_buffer, mark);
+          args[++i] = PT > mark ? point_marker : BVAR (current_buffer, mark);
           varies[i] = 4;
           break;
 
diff --git a/src/callproc.c b/src/callproc.c
index 4bf1da04e1a..2e9a8950700 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -77,7 +77,7 @@ static Lisp_Object Vtemp_file_name_pattern;
 
 /* True if we are about to fork off a synchronous process or if we
    are waiting for it.  */
-int synch_process_alive;
+bool synch_process_alive;
 
 /* Nonzero => this is a string explaining death of synchronous subprocess.  */
 const char *synch_process_death;
@@ -94,8 +94,8 @@ int synch_process_retcode;
    On MSDOS, delete the temporary file on any kind of termination.
    On Unix, kill the process and any children on termination by signal.  */
 
-/* Nonzero if this is termination due to exit.  */
-static int call_process_exited;
+/* True if this is termination due to exit.  */
+static bool call_process_exited;
 
 static Lisp_Object
 call_process_kill (Lisp_Object fdpid)
@@ -190,7 +190,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
   (ptrdiff_t nargs, Lisp_Object *args)
 {
   Lisp_Object infile, buffer, current_dir, path, cleanup_info_tail;
-  int display_p;
+  bool display_p;
   int fd[2];
   int filefd;
 #define CALLPROC_BUFFER_SIZE_MIN (16 * 1024)
@@ -217,7 +217,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
   struct coding_system argument_coding; /* coding-system of arguments */
   /* Set to the return value of Ffind_operation_coding_system.  */
   Lisp_Object coding_systems;
-  int output_to_buffer = 1;
+  bool output_to_buffer = 1;
 
   /* Qt denotes that Ffind_operation_coding_system is not yet called.  */
   coding_systems = Qt;
@@ -241,7 +241,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
     /* If arguments are supplied, we may have to encode them.  */
     if (nargs >= 5)
       {
-        int must_encode = 0;
+        bool must_encode = 0;
         Lisp_Object coding_attrs;
 
         for (i = 4; i < nargs; i++)
@@ -610,12 +610,12 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
       Lisp_Object volatile buffer_volatile = buffer;
       Lisp_Object volatile coding_systems_volatile = coding_systems;
       Lisp_Object volatile current_dir_volatile = current_dir;
-      int volatile display_p_volatile = display_p;
+      bool volatile display_p_volatile = display_p;
+      bool volatile output_to_buffer_volatile = output_to_buffer;
+      bool volatile sa_must_free_volatile = sa_must_free;
       int volatile fd1_volatile = fd1;
       int volatile fd_error_volatile = fd_error;
       int volatile fd_output_volatile = fd_output;
-      int volatile output_to_buffer_volatile = output_to_buffer;
-      int volatile sa_must_free_volatile = sa_must_free;
       ptrdiff_t volatile sa_count_volatile = sa_count;
       unsigned char const **volatile new_argv_volatile = new_argv;
 
@@ -766,11 +766,11 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
 
   if (output_to_buffer)
     {
-      register int nread;
-      int first = 1;
+      int nread;
+      bool first = 1;
       EMACS_INT total_read = 0;
       int carryover = 0;
-      int display_on_the_fly = display_p;
+      bool display_on_the_fly = display_p;
       struct coding_system saved_coding;
 
       saved_coding = process_coding;
@@ -1086,7 +1086,7 @@ static char **
 add_env (char **env, char **new_env, char *string)
 {
   char **ep;
-  int ok = 1;
+  bool ok = 1;
   if (string == NULL)
     return new_env;
 
@@ -1126,8 +1126,7 @@ add_env (char **env, char **new_env, char *string)
    Therefore, the superior process must save and restore the value
    of environ around the vfork and the call to this function.
 
-   SET_PGRP is nonzero if we should put the subprocess into a separate
-   process group.
+   If SET_PGRP, put the subprocess into a separate process group.
 
    CURRENT_DIR is an elisp string giving the path of the current
    directory the subprocess should have.  Since we can't really signal
@@ -1135,7 +1134,8 @@ add_env (char **env, char **new_env, char *string)
    executable directory by the parent.  */
 
 int
-child_setup (int in, int out, int err, register char **new_argv, int set_pgrp, Lisp_Object current_dir)
+child_setup (int in, int out, int err, char **new_argv, bool set_pgrp,
+             Lisp_Object current_dir)
 {
   char **env;
   char *pwd_var;
@@ -1394,7 +1394,7 @@ relocate_fd (int fd, int minfd)
 }
 #endif /* not WINDOWSNT */
 
-static int
+static bool
 getenv_internal_1 (const char *var, ptrdiff_t varlen, char **value,
                    ptrdiff_t *valuelen, Lisp_Object env)
 {
@@ -1429,7 +1429,7 @@ getenv_internal_1 (const char *var, ptrdiff_t varlen, char **value,
   return 0;
 }
 
-static int
+static bool
 getenv_internal (const char *var, ptrdiff_t varlen, char **value,
                  ptrdiff_t *valuelen, Lisp_Object frame)
 {
diff --git a/src/casefiddle.c b/src/casefiddle.c
index 81e84252b72..1102054b153 100644
--- a/src/casefiddle.c
+++ b/src/casefiddle.c
@@ -35,8 +35,8 @@ Lisp_Object Qidentity;
 static Lisp_Object
 casify_object (enum case_action flag, Lisp_Object obj)
 {
-  register int c, c1;
-  register int inword = flag == CASE_DOWN;
+  int c, c1;
+  bool inword = flag == CASE_DOWN;
 
   /* If the case table is flagged as modified, rescan it.  */
   if (NILP (XCHAR_TABLE (BVAR (current_buffer, downcase_table))->extras[1]))
@@ -47,7 +47,8 @@ casify_object (enum case_action flag, Lisp_Object obj)
       int flagbits = (CHAR_ALT | CHAR_SUPER | CHAR_HYPER
                       | CHAR_SHIFT | CHAR_CTL | CHAR_META);
       int flags = XINT (obj) & flagbits;
-      int multibyte = ! NILP (BVAR (current_buffer, enable_multibyte_characters));
+      bool multibyte = ! NILP (BVAR (current_buffer,
+                                     enable_multibyte_characters));
 
       /* If the character has higher bits set
          above the flags, return it unchanged.
@@ -189,9 +190,9 @@ The argument object is not altered--the value is a copy.  */)
 static void
 casify_region (enum case_action flag, Lisp_Object b, Lisp_Object e)
 {
-  register int c;
-  register int inword = flag == CASE_DOWN;
-  register int multibyte = !NILP (BVAR (current_buffer, enable_multibyte_characters));
+  int c;
+  bool inword = flag == CASE_DOWN;
+  bool multibyte = !NILP (BVAR (current_buffer, enable_multibyte_characters));
   ptrdiff_t start, end;
   ptrdiff_t start_byte;
 
diff --git a/src/casetab.c b/src/casetab.c
index a163d5204f8..3e22d0d0b77 100644
--- a/src/casetab.c
+++ b/src/casetab.c
@@ -79,7 +79,7 @@ This is the one used for new buffers.  */)
   return Vascii_downcase_table;
 }
 
-static Lisp_Object set_case_table (Lisp_Object table, int standard);
+static Lisp_Object set_case_table (Lisp_Object, bool);
 
 DEFUN ("set-case-table", Fset_case_table, Sset_case_table, 1, 1, 0,
        doc: /* Select a new case table for the current buffer.
@@ -113,7 +113,7 @@ See `set-case-table' for more info on case tables.  */)
 }
 
 static Lisp_Object
-set_case_table (Lisp_Object table, int standard)
+set_case_table (Lisp_Object table, bool standard)
 {
   Lisp_Object up, canon, eqv;
 
diff --git a/src/category.c b/src/category.c
index 1c9085fd558..80dc6938d8b 100644
--- a/src/category.c
+++ b/src/category.c
@@ -406,17 +406,17 @@ then delete CATEGORY from the category set instead of adding it.  */)
   return Qnil;
 }
 
-/* Return 1 if there is a word boundary between two word-constituent
-   characters C1 and C2 if they appear in this order, else return 0.
+/* Return true if there is a word boundary between two word-constituent
+   characters C1 and C2 if they appear in this order.
    Use the macro WORD_BOUNDARY_P instead of calling this function
    directly.  */
 
-int
+bool
 word_boundary_p (int c1, int c2)
 {
   Lisp_Object category_set1, category_set2;
   Lisp_Object tail;
-  int default_result;
+  bool default_result;
 
   if (EQ (CHAR_TABLE_REF (Vchar_script_table, c1),
           CHAR_TABLE_REF (Vchar_script_table, c2)))
diff --git a/src/category.h b/src/category.h
index 9fb981ed383..17cd203db45 100644
--- a/src/category.h
+++ b/src/category.h
@@ -77,14 +77,14 @@ INLINE_HEADER_BEGIN
 /* Return the category set of character C in the current category table.  */
 #define CATEGORY_SET(c) char_category_set (c)
 
-/* Return 1 if CATEGORY_SET contains CATEGORY, else return 0.
+/* Return true if CATEGORY_SET contains CATEGORY.
    The faster version of `!NILP (Faref (category_set, category))'.  */
 #define CATEGORY_MEMBER(category, category_set)                         \
   ((XCATEGORY_SET (category_set)->data[(category) / 8]                  \
     >> ((category) % 8)) & 1)
 
-/* Return 1 if category set of CH contains CATEGORY, else return 0.  */
-CATEGORY_INLINE int
+/* Return true if category set of CH contains CATEGORY.  */
+CATEGORY_INLINE bool
 CHAR_HAS_CATEGORY (int ch, int category)
 {
   Lisp_Object category_set = CATEGORY_SET (ch);
@@ -108,14 +108,14 @@ CHAR_HAS_CATEGORY (int ch, int category)
 #define CATEGORY_TABLE_VERSION (table) \
   Fchar_table_extra_slot (table, make_number (1))
 
-/* Return 1 if there is a word boundary between two word-constituent
-   characters C1 and C2 if they appear in this order, else return 0.
+/* Return true if there is a word boundary between two
+   word-constituent characters C1 and C2 if they appear in this order.
    There is no word boundary between two word-constituent ASCII and
    Latin-1 characters.  */
 #define WORD_BOUNDARY_P(c1, c2)                                 \
   (!(SINGLE_BYTE_CHAR_P (c1) && SINGLE_BYTE_CHAR_P (c2))        \
    && word_boundary_p (c1, c2))
 
-extern int word_boundary_p (int, int);
+extern bool word_boundary_p (int, int);
 
 INLINE_HEADER_END
diff --git a/src/character.c b/src/character.c
index b2acf36ec15..cfaaf8eeca9 100644
--- a/src/character.c
+++ b/src/character.c
@@ -427,7 +427,7 @@ lisp_string_width (Lisp_Object string, ptrdiff_t precision,
   /* This set multibyte to 0 even if STRING is multibyte when it
      contains only ascii and eight-bit-graphic, but that's
      intentional.  */
-  int multibyte = len < SBYTES (string);
+  bool multibyte = len < SBYTES (string);
   unsigned char *str = SDATA (string);
   ptrdiff_t i = 0, i_byte = 0;
   ptrdiff_t width = 0;
@@ -765,13 +765,10 @@ str_as_unibyte (unsigned char *str, ptrdiff_t bytes)
    corresponding byte and store in DST.  CHARS is the number of
    characters in SRC.  The value is the number of bytes stored in DST.
    Usually, the value is the same as CHARS, but is less than it if SRC
-   contains a non-ASCII, non-eight-bit character.  If ACCEPT_LATIN_1
-   is nonzero, a Latin-1 character is accepted and converted to a byte
-   of that character code.
-   Note: Currently the arg ACCEPT_LATIN_1 is not used.  */
+   contains a non-ASCII, non-eight-bit character.  */
 
 ptrdiff_t
-str_to_unibyte (const unsigned char *src, unsigned char *dst, ptrdiff_t chars, int accept_latin_1)
+str_to_unibyte (const unsigned char *src, unsigned char *dst, ptrdiff_t chars)
 {
   ptrdiff_t i;
 
@@ -781,8 +778,7 @@ str_to_unibyte (const unsigned char *src, unsigned char *dst, ptrdiff_t chars, i
 
       if (CHAR_BYTE8_P (c))
         c = CHAR_TO_BYTE8 (c);
-      else if (! ASCII_CHAR_P (c)
-               && (! accept_latin_1 || c >= 0x100))
+      else if (! ASCII_CHAR_P (c))
         return i;
       *dst++ = c;
     }
@@ -793,7 +789,7 @@ str_to_unibyte (const unsigned char *src, unsigned char *dst, ptrdiff_t chars, i
 static ptrdiff_t
 string_count_byte8 (Lisp_Object string)
 {
-  int multibyte = STRING_MULTIBYTE (string);
+  bool multibyte = STRING_MULTIBYTE (string);
   ptrdiff_t nbytes = SBYTES (string);
   unsigned char *p = SDATA (string);
   unsigned char *pend = p + nbytes;
@@ -825,7 +821,7 @@ string_escape_byte8 (Lisp_Object string)
 {
   ptrdiff_t nchars = SCHARS (string);
   ptrdiff_t nbytes = SBYTES (string);
-  int multibyte = STRING_MULTIBYTE (string);
+  bool multibyte = STRING_MULTIBYTE (string);
   ptrdiff_t byte8_count;
   const unsigned char *src, *src_end;
   unsigned char *dst;
diff --git a/src/character.h b/src/character.h
index 332dfee373a..70d4e67a978 100644
--- a/src/character.h
+++ b/src/character.h
@@ -676,7 +676,6 @@ extern int string_char (const unsigned char *,
                         const unsigned char **, int *);
 
 extern int translate_char (Lisp_Object, int c);
-extern int char_printable_p (int c);
 extern void parse_str_as_multibyte (const unsigned char *,
                                     ptrdiff_t, ptrdiff_t *, ptrdiff_t *);
 extern ptrdiff_t count_size_as_multibyte (const unsigned char *, ptrdiff_t);
@@ -685,7 +684,7 @@ extern ptrdiff_t str_as_multibyte (unsigned char *, ptrdiff_t, ptrdiff_t,
 extern ptrdiff_t str_to_multibyte (unsigned char *, ptrdiff_t, ptrdiff_t);
 extern ptrdiff_t str_as_unibyte (unsigned char *, ptrdiff_t);
 extern ptrdiff_t str_to_unibyte (const unsigned char *, unsigned char *,
-                                 ptrdiff_t, int);
+                                 ptrdiff_t);
 extern ptrdiff_t strwidth (const char *, ptrdiff_t);
 extern ptrdiff_t c_string_width (const unsigned char *, ptrdiff_t, int,
                                  ptrdiff_t *, ptrdiff_t *);
diff --git a/src/charset.c b/src/charset.c
index 3e286fa947d..0673790e91c 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -215,7 +215,7 @@ static struct
 
 /* Set to 1 to warn that a charset map is loaded and thus a buffer
    text and a string data may be relocated.  */
-int charset_map_loaded;
+bool charset_map_loaded;
 
 struct charset_map_entries
 {
@@ -256,7 +256,7 @@ load_charset_map (struct charset *charset, struct charset_map_entries *entries,
 {
   Lisp_Object vec IF_LINT (= Qnil), table IF_LINT (= Qnil);
   unsigned max_code = CHARSET_MAX_CODE (charset);
-  int ascii_compatible_p = charset->ascii_compatible_p;
+  bool ascii_compatible_p = charset->ascii_compatible_p;
   int min_char, max_char, nonascii_min_char;
   int i;
   unsigned char *fast_map = charset->fast_map;
@@ -423,7 +423,7 @@ load_charset_map (struct charset *charset, struct charset_map_entries *entries,
    paying attention to comment character '#'.  */
 
 static inline unsigned
-read_hex (FILE *fp, int *eof, int *overflow)
+read_hex (FILE *fp, bool *eof, bool *overflow)
 {
   int c;
   unsigned n;
@@ -512,7 +512,7 @@ load_charset_map_from_file (struct charset *charset, Lisp_Object mapfile, int co
     {
       unsigned from, to, c;
       int idx;
-      int eof = 0, overflow = 0;
+      bool eof = 0, overflow = 0;
 
       from = read_hex (fp, &eof, &overflow);
       if (eof)
@@ -717,10 +717,8 @@ map_charset_chars (void (*c_function)(Lisp_Object, Lisp_Object), Lisp_Object fun
                    Lisp_Object arg, struct charset *charset, unsigned from, unsigned to)
 {
   Lisp_Object range;
-  int partial;
-
-  partial = (from > CHARSET_MIN_CODE (charset)
-             || to < CHARSET_MAX_CODE (charset));
+  bool partial = (from > CHARSET_MIN_CODE (charset)
+                  || to < CHARSET_MAX_CODE (charset));
 
   if (CHARSET_METHOD (charset) == CHARSET_METHOD_OFFSET)
     {
@@ -855,7 +853,7 @@ usage: (define-charset-internal ...)  */)
   struct charset charset;
   int id;
   int dimension;
-  int new_definition_p;
+  bool new_definition_p;
   int nchars;
 
   if (nargs != charset_arg_max)
@@ -1250,7 +1248,7 @@ define_charset_internal (Lisp_Object name,
                          const char *code_space_chars,
                          unsigned min_code, unsigned max_code,
                          int iso_final, int iso_revision, int emacs_mule_id,
-                         int ascii_compatible, int supplementary,
+                         bool ascii_compatible, bool supplementary,
                          int code_offset)
 {
   const unsigned char *code_space = (const unsigned char *) code_space_chars;
@@ -1448,7 +1446,7 @@ if CHARSET is designated instead.  */)
   (Lisp_Object dimension, Lisp_Object chars, Lisp_Object final_char, Lisp_Object charset)
 {
   int id;
-  int chars_flag;
+  bool chars_flag;
 
   CHECK_CHARSET_GET_ID (charset, id);
   check_iso_charset_parameter (dimension, chars, final_char);
@@ -1499,7 +1497,9 @@ string_xstring_p (Lisp_Object string)
    It may lookup a translation table TABLE if supplied.  */
 
 static void
-find_charsets_in_text (const unsigned char *ptr, ptrdiff_t nchars, ptrdiff_t nbytes, Lisp_Object charsets, Lisp_Object table, int multibyte)
+find_charsets_in_text (const unsigned char *ptr, ptrdiff_t nchars,
+                       ptrdiff_t nbytes, Lisp_Object charsets,
+                       Lisp_Object table, bool multibyte)
 {
   const unsigned char *pend = ptr + nbytes;
 
@@ -1549,7 +1549,7 @@ only `ascii', `eight-bit-control', and `eight-bit-graphic'.  */)
   ptrdiff_t from, from_byte, to, stop, stop_byte;
   int i;
   Lisp_Object val;
-  int multibyte = ! NILP (BVAR (current_buffer, enable_multibyte_characters));
+  bool multibyte = ! NILP (BVAR (current_buffer, enable_multibyte_characters));
 
   validate_region (&beg, &end);
   from = XFASTINT (beg);
@@ -1735,7 +1735,7 @@ decode_char (struct charset *charset, unsigned int code)
 /* Variable used temporarily by the macro ENCODE_CHAR.  */
 Lisp_Object charset_work;
 
-/* Return a code-point of CHAR in CHARSET.  If CHAR doesn't belong to
+/* Return a code-point of C in CHARSET.  If C doesn't belong to
    CHARSET, return CHARSET_INVALID_CODE (CHARSET).  If STRICT is true,
    use CHARSET's strict_max_char instead of max_char.  */
 
@@ -1978,7 +1978,7 @@ is specified.  */)
 struct charset *
 char_charset (int c, Lisp_Object charset_list, unsigned int *code_return)
 {
-  int maybe_null = 0;
+  bool maybe_null = 0;
 
   if (NILP (charset_list))
     charset_list = Vcharset_ordered_list;
@@ -2106,7 +2106,7 @@ DIMENSION, CHARS, and FINAL-CHAR.  */)
   (Lisp_Object dimension, Lisp_Object chars, Lisp_Object final_char)
 {
   int id;
-  int chars_flag;
+  bool chars_flag;
 
   check_iso_charset_parameter (dimension, chars, final_char);
   chars_flag = XFASTINT (chars) == 96;
diff --git a/src/charset.h b/src/charset.h
index 4ef8ddc2c33..50d230489fe 100644
--- a/src/charset.h
+++ b/src/charset.h
@@ -173,12 +173,24 @@ struct charset
      check if a code-point is in a valid range.  */
   unsigned char *code_space_mask;
 
-  /* 1 if there's no gap in code-points.  */
-  int code_linear_p;
+  /* True if there's no gap in code-points.  */
+  unsigned code_linear_p : 1;
 
-  /* If the charset is treated as 94-chars in ISO-2022, the value is 0.
-     If the charset is treated as 96-chars in ISO-2022, the value is 1.  */
-  int iso_chars_96;
+  /* True if the charset is treated as 96 chars in ISO-2022
+     as opposed to 94 chars.  */
+  unsigned iso_chars_96 : 1;
+
+  /* True if the charset is compatible with ASCII.  */
+  unsigned ascii_compatible_p : 1;
+
+  /* True if the charset is supplementary.  */
+  unsigned supplementary_p : 1;
+
+  /* True if all the code points are representable by Lisp_Int.  */
+  unsigned compact_codes_p : 1;
+
+  /* True if the charset is unified with Unicode.  */
+  unsigned unified_p : 1;
 
   /* ISO final byte of the charset: 48..127.  It may be -1 if the
      charset doesn't conform to ISO-2022.  */
@@ -192,15 +204,6 @@ struct charset
      version.  Otherwise, -1.  */
   int emacs_mule_id;
 
-  /* Nonzero if the charset is compatible with ASCII.  */
-  int ascii_compatible_p;
-
-  /* Nonzero if the charset is supplementary.  */
-  int supplementary_p;
-
-  /* Nonzero if all the code points are representable by Lisp_Int.  */
-  int compact_codes_p;
-
   /* The method for encoding/decoding characters of the charset.  */
   enum charset_method method;
 
@@ -239,8 +242,6 @@ struct charset
   /* Offset value to calculate a character code from code-point, and
      visa versa.  */
   int code_offset;
-
-  int unified_p;
 };
 
 /* Hash table of charset symbols vs. the corresponding attribute
@@ -456,7 +457,7 @@ extern Lisp_Object charset_work;
 
 /* Set to 1 when a charset map is loaded to warn that a buffer text
    and a string data may be relocated.  */
-extern int charset_map_loaded;
+extern bool charset_map_loaded;
 
 
 /* Set CHARSET to the charset highest priority of C, CODE to the
@@ -474,10 +475,10 @@ extern int charset_map_loaded;
    macro ISO_CHARSET_TABLE (DIMENSION, CHARS, FINAL_CHAR).  */
 extern int iso_charset_table[ISO_MAX_DIMENSION][ISO_MAX_CHARS][ISO_MAX_FINAL];
 
-/* A charset of type iso2022 who has DIMENSION, CHARS, and FINAL
+/* A charset of type iso2022 who has DIMENSION, CHARS_96, and FINAL
    (final character).  */
 #define ISO_CHARSET_TABLE(dimension, chars_96, final)   \
-  iso_charset_table[(dimension) - 1][(chars_96)][(final)]
+  iso_charset_table[(dimension) - 1][chars_96][final]
 
 /* Nonzero if the charset who has FAST_MAP may contain C.  */
 #define CHARSET_FAST_MAP_REF(c, fast_map)               \
@@ -495,7 +496,7 @@ extern int iso_charset_table[ISO_MAX_DIMENSION][ISO_MAX_CHARS][ISO_MAX_FINAL];
 
 
 
-/* 1 if CHARSET may contain the character C.  */
+/* True if CHARSET may contain the character C.  */
 #define CHAR_CHARSET_P(c, charset)                                       \
   ((ASCII_CHAR_P (c) && (charset)->ascii_compatible_p)                   \
    || ((CHARSET_UNIFIED_P (charset)                                      \
diff --git a/src/chartab.c b/src/chartab.c
index 711a49ed397..c14df0ebac6 100644
--- a/src/chartab.c
+++ b/src/chartab.c
@@ -200,7 +200,7 @@ copy_char_table (Lisp_Object table)
 }
 
 static Lisp_Object
-sub_char_table_ref (Lisp_Object table, int c, int is_uniprop)
+sub_char_table_ref (Lisp_Object table, int c, bool is_uniprop)
 {
   struct Lisp_Sub_Char_Table *tbl = XSUB_CHAR_TABLE (table);
   int depth = XINT (tbl->depth);
@@ -245,7 +245,7 @@ char_table_ref (Lisp_Object table, int c)
 
 static Lisp_Object
 sub_char_table_ref_and_range (Lisp_Object table, int c, int *from, int *to,
-                              Lisp_Object defalt, int is_uniprop)
+                              Lisp_Object defalt, bool is_uniprop)
 {
   struct Lisp_Sub_Char_Table *tbl = XSUB_CHAR_TABLE (table);
   int depth = XINT (tbl->depth);
@@ -320,7 +320,7 @@ char_table_ref_and_range (Lisp_Object table, int c, int *from, int *to)
   struct Lisp_Char_Table *tbl = XCHAR_TABLE (table);
   int chartab_idx = CHARTAB_IDX (c, 0, 0), idx;
   Lisp_Object val;
-  int is_uniprop = UNIPROP_TABLE_P (table);
+  bool is_uniprop = UNIPROP_TABLE_P (table);
 
   val = tbl->contents[chartab_idx];
   if (*from < 0)
@@ -382,7 +382,7 @@ char_table_ref_and_range (Lisp_Object table, int c, int *from, int *to)
 
 
 static void
-sub_char_table_set (Lisp_Object table, int c, Lisp_Object val, int is_uniprop)
+sub_char_table_set (Lisp_Object table, int c, Lisp_Object val, bool is_uniprop)
 {
   struct Lisp_Sub_Char_Table *tbl = XSUB_CHAR_TABLE (table);
   int depth = XINT ((tbl)->depth);
@@ -438,7 +438,7 @@ char_table_set (Lisp_Object table, int c, Lisp_Object val)
 
 static void
 sub_char_table_set_range (Lisp_Object table, int from, int to, Lisp_Object val,
-                          int is_uniprop)
+                          bool is_uniprop)
 {
   struct Lisp_Sub_Char_Table *tbl = XSUB_CHAR_TABLE (table);
   int depth = XINT ((tbl)->depth);
@@ -484,7 +484,7 @@ char_table_set_range (Lisp_Object table, int from, int to, Lisp_Object val)
     char_table_set (table, from, val);
   else
     {
-      int is_uniprop = UNIPROP_TABLE_P (table);
+      bool is_uniprop = UNIPROP_TABLE_P (table);
       int lim = CHARTAB_IDX (to, 0, 0);
       int i, c;
 
@@ -683,7 +683,8 @@ optimize_sub_char_table (Lisp_Object table, Lisp_Object test)
   struct Lisp_Sub_Char_Table *tbl = XSUB_CHAR_TABLE (table);
   int depth = XINT (tbl->depth);
   Lisp_Object elt, this;
-  int i, optimizable;
+  int i;
+  bool optimizable;
 
   elt = XSUB_CHAR_TABLE (table)->contents[0];
   if (SUB_CHAR_TABLE_P (elt))
@@ -762,7 +763,7 @@ map_sub_char_table (void (*c_function) (Lisp_Object, Lisp_Object, Lisp_Object),
   int chars_in_block;
   int from = XINT (XCAR (range)), to = XINT (XCDR (range));
   int i, c;
-  int is_uniprop = UNIPROP_TABLE_P (top);
+  bool is_uniprop = UNIPROP_TABLE_P (top);
   uniprop_decoder_t decoder = UNIPROP_GET_DECODER (top);
 
   if (SUB_CHAR_TABLE_P (table))
@@ -811,7 +812,7 @@ map_sub_char_table (void (*c_function) (Lisp_Object, Lisp_Object, Lisp_Object),
             this = XCHAR_TABLE (top)->defalt;
           if (!EQ (val, this))
             {
-              int different_value = 1;
+              bool different_value = 1;
 
               if (NILP (val))
                 {
diff --git a/src/cmds.c b/src/cmds.c
index b416135ee9e..90d3cd6dced 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -47,10 +47,10 @@ DEFUN ("forward-point", Fforward_point, Sforward_point, 1, 1, 0,
   return make_number (PT + XINT (n));
 }
 
-/* Add N to point; or subtract N if FORWARD is zero.  N defaults to 1.
+/* Add N to point; or subtract N if FORWARD is false.  N defaults to 1.
    Validate the new location.  Return nil.  */
 static Lisp_Object
-move_point (Lisp_Object n, int forward)
+move_point (Lisp_Object n, bool forward)
 {
   /* This used to just set point to point + XINT (n), and then check
      to see if it was within boundaries.  But now that SET_PT can
@@ -277,7 +277,7 @@ After insertion, the value of `auto-fill-function' is called if the
 At the end, it runs `post-self-insert-hook'.  */)
   (Lisp_Object n)
 {
-  int remove_boundary = 1;
+  bool remove_boundary = 1;
   CHECK_NATNUM (n);
 
   if (!EQ (Vthis_command, KVAR (current_kboard, Vlast_command)))
@@ -438,7 +438,7 @@ internal_self_insert (int c, EMACS_INT n)
                   : UNIBYTE_TO_CHAR (XFASTINT (Fprevious_char ())))
           == Sword))
     {
-      int modiff = MODIFF;
+      EMACS_INT modiff = MODIFF;
       Lisp_Object sym;
 
       sym = call0 (Qexpand_abbrev);
diff --git a/src/coding.c b/src/coding.c
index 971686dc180..02e7b34695e 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -147,18 +147,18 @@ STRUCT CODING_SYSTEM
   CODING conforms to the format of XXX, and update the members of
   DETECT_INFO.
 
-  Return 1 if the byte sequence conforms to XXX, otherwise return 0.
+  Return true if the byte sequence conforms to XXX.
 
   Below is the template of these functions.  */
 
 #if 0
-static int
+static bool
 detect_coding_XXX (struct coding_system *coding,
                    struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   ptrdiff_t consumed_chars = 0;
   int found = 0;
   ...;
@@ -212,7 +212,7 @@ decode_coding_XXXX (struct coding_system *coding)
   /* A buffer to produce decoded characters.  */
   int *charbuf = coding->charbuf + coding->charbuf_used;
   int *charbuf_end = coding->charbuf + coding->charbuf_size;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
 
   while (1)
     {
@@ -260,7 +260,7 @@ decode_coding_XXXX (struct coding_system *coding)
 static void
 encode_coding_XXX (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf->charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
@@ -651,8 +651,8 @@ static struct coding_system coding_categories[coding_category_max];
 
 /* Safely get one byte from the source text pointed by SRC which ends
    at SRC_END, and set C to that byte.  If there are not enough bytes
-   in the source, it jumps to `no_more_source'.  If multibytep is
-   nonzero, and a multibyte character is found at SRC, set C to the
+   in the source, it jumps to 'no_more_source'.  If MULTIBYTEP,
+   and a multibyte character is found at SRC, set C to the
    negative value of the character code.  The caller should declare
    and set these variables appropriately in advance:
         src, src_end, multibytep */
@@ -685,7 +685,7 @@ static struct coding_system coding_categories[coding_category_max];
 /* Safely get two bytes from the source text pointed by SRC which ends
    at SRC_END, and set C1 and C2 to those bytes while skipping the
    heading multibyte characters.  If there are not enough bytes in the
-   source, it jumps to `no_more_source'.  If multibytep is nonzero and
+   source, it jumps to 'no_more_source'.  If MULTIBYTEP and
    a multibyte character is found for C2, set C2 to the negative value
    of the character code.  The caller should declare and set these
    variables appropriately in advance:
@@ -746,8 +746,8 @@ static struct coding_system coding_categories[coding_category_max];
 
 
 /* Store a byte C in the place pointed by DST and increment DST to the
-   next free point, and increment PRODUCED_CHARS.  If MULTIBYTEP is
-   nonzero, store in an appropriate multibyte from.  The caller should
+   next free point, and increment PRODUCED_CHARS.  If MULTIBYTEP,
+   store in an appropriate multibyte form.  The caller should
    declare and set the variables `dst' and `multibytep' appropriately
    in advance.  */
 
@@ -806,83 +806,6 @@ static struct coding_system coding_categories[coding_category_max];
   } while (0)
 
 
-/* Prototypes for static functions.  */
-static void record_conversion_result (struct coding_system *coding,
-                                      enum coding_result_code result);
-static int detect_coding_utf_8 (struct coding_system *,
-                                struct coding_detection_info *info);
-static void decode_coding_utf_8 (struct coding_system *);
-static int encode_coding_utf_8 (struct coding_system *);
-
-static int detect_coding_utf_16 (struct coding_system *,
-                                 struct coding_detection_info *info);
-static void decode_coding_utf_16 (struct coding_system *);
-static int encode_coding_utf_16 (struct coding_system *);
-
-static int detect_coding_iso_2022 (struct coding_system *,
-                                   struct coding_detection_info *info);
-static void decode_coding_iso_2022 (struct coding_system *);
-static int encode_coding_iso_2022 (struct coding_system *);
-
-static int detect_coding_emacs_mule (struct coding_system *,
-                                     struct coding_detection_info *info);
-static void decode_coding_emacs_mule (struct coding_system *);
-static int encode_coding_emacs_mule (struct coding_system *);
-
-static int detect_coding_sjis (struct coding_system *,
-                               struct coding_detection_info *info);
-static void decode_coding_sjis (struct coding_system *);
-static int encode_coding_sjis (struct coding_system *);
-
-static int detect_coding_big5 (struct coding_system *,
-                               struct coding_detection_info *info);
-static void decode_coding_big5 (struct coding_system *);
-static int encode_coding_big5 (struct coding_system *);
-
-static int detect_coding_ccl (struct coding_system *,
-                              struct coding_detection_info *info);
-static void decode_coding_ccl (struct coding_system *);
-static int encode_coding_ccl (struct coding_system *);
-
-static void decode_coding_raw_text (struct coding_system *);
-static int encode_coding_raw_text (struct coding_system *);
-
-static void coding_set_source (struct coding_system *);
-static ptrdiff_t coding_change_source (struct coding_system *);
-static void coding_set_destination (struct coding_system *);
-static ptrdiff_t coding_change_destination (struct coding_system *);
-static void coding_alloc_by_realloc (struct coding_system *, ptrdiff_t);
-static void coding_alloc_by_making_gap (struct coding_system *,
-                                        ptrdiff_t, ptrdiff_t);
-static unsigned char *alloc_destination (struct coding_system *,
-                                         ptrdiff_t, unsigned char *);
-static void setup_iso_safe_charsets (Lisp_Object);
-static ptrdiff_t encode_designation_at_bol (struct coding_system *,
-                                      int *, int *, unsigned char *);
-static int detect_eol (const unsigned char *,
-                       ptrdiff_t, enum coding_category);
-static Lisp_Object adjust_coding_eol_type (struct coding_system *, int);
-static void decode_eol (struct coding_system *);
-static Lisp_Object get_translation_table (Lisp_Object, int, int *);
-static Lisp_Object get_translation (Lisp_Object, int *, int *);
-static int produce_chars (struct coding_system *, Lisp_Object, int);
-static inline void produce_charset (struct coding_system *, int *,
-                                    ptrdiff_t);
-static void produce_annotation (struct coding_system *, ptrdiff_t);
-static int decode_coding (struct coding_system *);
-static inline int *handle_composition_annotation (ptrdiff_t, ptrdiff_t,
-                                                  struct coding_system *,
-                                                  int *, ptrdiff_t *);
-static inline int *handle_charset_annotation (ptrdiff_t, ptrdiff_t,
-                                              struct coding_system *,
-                                              int *, ptrdiff_t *);
-static void consume_chars (struct coding_system *, Lisp_Object, int);
-static int encode_coding (struct coding_system *);
-static Lisp_Object make_conversion_work_buffer (int);
-static Lisp_Object code_conversion_restore (Lisp_Object);
-static inline int char_encodable_p (int, Lisp_Object);
-static Lisp_Object make_subsidiaries (Lisp_Object);
-
 static void
 record_conversion_result (struct coding_system *coding,
                           enum coding_result_code result)
@@ -1264,8 +1187,7 @@ alloc_destination (struct coding_system *coding, ptrdiff_t nbytes,
 /*** 3. UTF-8 ***/
 
 /* See the above "GENERAL NOTES on `detect_coding_XXX ()' functions".
-   Check if a text is encoded in UTF-8.  If it is, return 1, else
-   return 0.  */
+   Return true if a text is encoded in UTF-8.  */
 
 #define UTF_8_1_OCTET_P(c)         ((c) < 0x80)
 #define UTF_8_EXTRA_OCTET_P(c)     (((c) & 0xC0) == 0x80)
@@ -1278,16 +1200,16 @@ alloc_destination (struct coding_system *coding, ptrdiff_t nbytes,
 #define UTF_8_BOM_2 0xBB
 #define UTF_8_BOM_3 0xBF
 
-static int
+static bool
 detect_coding_utf_8 (struct coding_system *coding,
                      struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source, *src_base;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   ptrdiff_t consumed_chars = 0;
-  int bom_found = 0;
-  int found = 0;
+  bool bom_found = 0;
+  bool found = 0;
 
   detect_info->checked |= CATEGORY_MASK_UTF_8;
   /* A coding system of this category is always ASCII compatible.  */
@@ -1371,10 +1293,10 @@ decode_coding_utf_8 (struct coding_system *coding)
   int *charbuf = coding->charbuf + coding->charbuf_used;
   int *charbuf_end = coding->charbuf + coding->charbuf_size;
   ptrdiff_t consumed_chars = 0, consumed_chars_base = 0;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   enum utf_bom_type bom = CODING_UTF_8_BOM (coding);
-  int eol_dos =
-    !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
+  bool eol_dos
+    = !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
   int byte_after_cr = -1;
 
   if (bom != utf_without_bom)
@@ -1513,10 +1435,10 @@ decode_coding_utf_8 (struct coding_system *coding)
 }
 
 
-static int
+static bool
 encode_coding_utf_8 (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
@@ -1577,8 +1499,7 @@ encode_coding_utf_8 (struct coding_system *coding)
 
 
 /* See the above "GENERAL NOTES on `detect_coding_XXX ()' functions".
-   Check if a text is encoded in one of UTF-16 based coding systems.
-   If it is, return 1, else return 0.  */
+   Return true if a text is encoded in one of UTF-16 based coding systems.  */
 
 #define UTF_16_HIGH_SURROGATE_P(val) \
   (((val) & 0xFC00) == 0xD800)
@@ -1587,13 +1508,13 @@ encode_coding_utf_8 (struct coding_system *coding)
   (((val) & 0xFC00) == 0xDC00)
 
 
-static int
+static bool
 detect_coding_utf_16 (struct coding_system *coding,
                       struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   int c1, c2;
 
   detect_info->checked |= CATEGORY_MASK_UTF_16;
@@ -1680,12 +1601,12 @@ decode_coding_utf_16 (struct coding_system *coding)
   /* We may produces at most 3 chars in one loop.  */
   int *charbuf_end = coding->charbuf + coding->charbuf_size - 2;
   ptrdiff_t consumed_chars = 0, consumed_chars_base = 0;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   enum utf_bom_type bom = CODING_UTF_16_BOM (coding);
   enum utf_16_endian_type endian = CODING_UTF_16_ENDIAN (coding);
   int surrogate = CODING_UTF_16_SURROGATE (coding);
-  int eol_dos =
-    !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
+  bool eol_dos
+    = !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
   int byte_after_cr1 = -1, byte_after_cr2 = -1;
 
   if (bom == utf_with_bom)
@@ -1795,17 +1716,17 @@ decode_coding_utf_16 (struct coding_system *coding)
   coding->charbuf_used = charbuf - coding->charbuf;
 }
 
-static int
+static bool
 encode_coding_utf_16 (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
   unsigned char *dst_end = coding->destination + coding->dst_bytes;
   int safe_room = 8;
   enum utf_bom_type bom = CODING_UTF_16_BOM (coding);
-  int big_endian = CODING_UTF_16_ENDIAN (coding) == utf_16_big_endian;
+  bool big_endian = CODING_UTF_16_ENDIAN (coding) == utf_16_big_endian;
   ptrdiff_t produced_chars = 0;
   int c;
 
@@ -1930,16 +1851,15 @@ char emacs_mule_bytes[256];
 
 
 /* See the above "GENERAL NOTES on `detect_coding_XXX ()' functions".
-   Check if a text is encoded in `emacs-mule'.  If it is, return 1,
-   else return 0.  */
+   Return true if a text is encoded in 'emacs-mule'.  */
 
-static int
+static bool
 detect_coding_emacs_mule (struct coding_system *coding,
                           struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source, *src_base;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   ptrdiff_t consumed_chars = 0;
   int c;
   int found = 0;
@@ -2029,12 +1949,12 @@ emacs_mule_char (struct coding_system *coding, const unsigned char *src,
 {
   const unsigned char *src_end = coding->source + coding->src_bytes;
   const unsigned char *src_base = src;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   int charset_ID;
   unsigned code;
   int c;
   int consumed_chars = 0;
-  int mseq_found = 0;
+  bool mseq_found = 0;
 
   ONE_MORE_BYTE (c);
   if (c < 0)
@@ -2411,12 +2331,12 @@ decode_coding_emacs_mule (struct coding_system *coding)
       /* We can produce up to 2 characters in a loop.  */
       - 1;
   ptrdiff_t consumed_chars = 0, consumed_chars_base;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   ptrdiff_t char_offset = coding->produced_char;
   ptrdiff_t last_offset = char_offset;
   int last_id = charset_ascii;
-  int eol_dos =
-    !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
+  bool eol_dos
+    = !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
   int byte_after_cr = -1;
   struct composition_status *cmp_status = &coding->spec.emacs_mule.cmp_status;
 
@@ -2657,10 +2577,10 @@ decode_coding_emacs_mule (struct coding_system *coding)
   } while (0);
 
 
-static int
+static bool
 encode_coding_emacs_mule (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
@@ -2722,7 +2642,7 @@ encode_coding_emacs_mule (struct coding_system *coding)
 
           if (preferred_charset_id >= 0)
             {
-              int result;
+              bool result;
 
               charset = CHARSET_FROM_ID (preferred_charset_id);
               CODING_CHAR_CHARSET_P (coding, dst, dst_end, c, charset, result);
@@ -3017,17 +2937,17 @@ setup_iso_safe_charsets (Lisp_Object attrs)
 
 
 /* See the above "GENERAL NOTES on `detect_coding_XXX ()' functions".
-   Check if a text is encoded in one of ISO-2022 based coding systems.
-   If it is, return 1, else return 0.  */
+   Return true if a text is encoded in one of ISO-2022 based coding
+   systems.  */
 
-static int
+static bool
 detect_coding_iso_2022 (struct coding_system *coding,
                         struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source, *src_base = src;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
-  int single_shifting = 0;
+  bool multibytep = coding->src_multibyte;
+  bool single_shifting = 0;
   int id;
   int c, c1;
   ptrdiff_t consumed_chars = 0;
@@ -3390,8 +3310,6 @@ detect_coding_iso_2022 (struct coding_system *coding,
 
 /* Finish the current composition as invalid.  */
 
-static int finish_composition (int *, struct composition_status *);
-
 static int
 finish_composition (int *charbuf, struct composition_status *cmp_status)
 {
@@ -3541,7 +3459,7 @@ decode_coding_iso_2022 (struct coding_system *coding)
   int *charbuf_end
     = coding->charbuf + coding->charbuf_size - (MAX_ANNOTATION_LENGTH * 3);
   ptrdiff_t consumed_chars = 0, consumed_chars_base;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   /* Charsets invoked to graphic plane 0 and 1 respectively.  */
   int charset_id_0 = CODING_ISO_INVOKED_CHARSET (coding, 0);
   int charset_id_1 = CODING_ISO_INVOKED_CHARSET (coding, 1);
@@ -3553,8 +3471,8 @@ decode_coding_iso_2022 (struct coding_system *coding)
   ptrdiff_t char_offset = coding->produced_char;
   ptrdiff_t last_offset = char_offset;
   int last_id = charset_ascii;
-  int eol_dos =
-    !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
+  bool eol_dos
+    = !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
   int byte_after_cr = -1;
   int i;
 
@@ -4282,7 +4200,7 @@ encode_invocation_designation (struct charset *charset,
                                struct coding_system *coding,
                                unsigned char *dst, ptrdiff_t *p_nchars)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   ptrdiff_t produced_chars = *p_nchars;
   int reg;                      /* graphic register number */
   int id = CHARSET_ID (charset);
@@ -4380,7 +4298,7 @@ encode_designation_at_bol (struct coding_system *coding,
   int r[4];
   int c, found = 0, reg;
   ptrdiff_t produced_chars = 0;
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   Lisp_Object attrs;
   Lisp_Object charset_list;
 
@@ -4422,21 +4340,21 @@ encode_designation_at_bol (struct coding_system *coding,
 
 /* See the above "GENERAL NOTES on `encode_coding_XXX ()' functions".  */
 
-static int
+static bool
 encode_coding_iso_2022 (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
   unsigned char *dst_end = coding->destination + coding->dst_bytes;
   int safe_room = 16;
-  int bol_designation
+  bool bol_designation
     = (CODING_ISO_FLAGS (coding) & CODING_ISO_FLAG_DESIGNATE_AT_BOL
        && CODING_ISO_BOL (coding));
   ptrdiff_t produced_chars = 0;
   Lisp_Object attrs, eol_type, charset_list;
-  int ascii_compatible;
+  bool ascii_compatible;
   int c;
   int preferred_charset_id = -1;
 
@@ -4523,8 +4441,9 @@ encode_coding_iso_2022 (struct coding_system *coding)
                     CODING_ISO_DESIGNATION (coding, i)
                       = CODING_ISO_INITIAL (coding, i);
                 }
-              bol_designation
-                = CODING_ISO_FLAGS (coding) & CODING_ISO_FLAG_DESIGNATE_AT_BOL;
+              bol_designation = ((CODING_ISO_FLAGS (coding)
+                                  & CODING_ISO_FLAG_DESIGNATE_AT_BOL)
+                                 != 0);
             }
           else if (CODING_ISO_FLAGS (coding) & CODING_ISO_FLAG_RESET_AT_CNTL)
             ENCODE_RESET_PLANE_AND_REGISTER ();
@@ -4551,7 +4470,7 @@ encode_coding_iso_2022 (struct coding_system *coding)
 
           if (preferred_charset_id >= 0)
             {
-              int result;
+              bool result;
 
               charset = CHARSET_FROM_ID (preferred_charset_id);
               CODING_CHAR_CHARSET_P (coding, dst, dst_end, c, charset, result);
@@ -4631,16 +4550,15 @@ encode_coding_iso_2022 (struct coding_system *coding)
   */
 
 /* See the above "GENERAL NOTES on `detect_coding_XXX ()' functions".
-   Check if a text is encoded in SJIS.  If it is, return
-   CATEGORY_MASK_SJIS, else return 0.  */
+   Return true if a text is encoded in SJIS.  */
 
-static int
+static bool
 detect_coding_sjis (struct coding_system *coding,
                     struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source, *src_base;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   ptrdiff_t consumed_chars = 0;
   int found = 0;
   int c;
@@ -4688,16 +4606,15 @@ detect_coding_sjis (struct coding_system *coding,
 }
 
 /* See the above "GENERAL NOTES on `detect_coding_XXX ()' functions".
-   Check if a text is encoded in BIG5.  If it is, return
-   CATEGORY_MASK_BIG5, else return 0.  */
+   Return true if a text is encoded in BIG5.  */
 
-static int
+static bool
 detect_coding_big5 (struct coding_system *coding,
                     struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source, *src_base;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   ptrdiff_t consumed_chars = 0;
   int found = 0;
   int c;
@@ -4735,8 +4652,7 @@ detect_coding_big5 (struct coding_system *coding,
   return 1;
 }
 
-/* See the above "GENERAL NOTES on `decode_coding_XXX ()' functions".
-   If SJIS_P is 1, decode SJIS text, else decode BIG5 test.  */
+/* See the above "GENERAL NOTES on `decode_coding_XXX ()' functions".  */
 
 static void
 decode_coding_sjis (struct coding_system *coding)
@@ -4750,15 +4666,15 @@ decode_coding_sjis (struct coding_system *coding)
   int *charbuf_end
     = coding->charbuf + coding->charbuf_size - (MAX_ANNOTATION_LENGTH * 2);
   ptrdiff_t consumed_chars = 0, consumed_chars_base;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   struct charset *charset_roman, *charset_kanji, *charset_kana;
   struct charset *charset_kanji2;
   Lisp_Object attrs, charset_list, val;
   ptrdiff_t char_offset = coding->produced_char;
   ptrdiff_t last_offset = char_offset;
   int last_id = charset_ascii;
-  int eol_dos =
-    !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
+  bool eol_dos
+    = !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
   int byte_after_cr = -1;
 
   CODING_GET_INFO (coding, attrs, charset_list);
@@ -4868,14 +4784,14 @@ decode_coding_big5 (struct coding_system *coding)
   int *charbuf_end
     = coding->charbuf + coding->charbuf_size - (MAX_ANNOTATION_LENGTH * 2);
   ptrdiff_t consumed_chars = 0, consumed_chars_base;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   struct charset *charset_roman, *charset_big5;
   Lisp_Object attrs, charset_list, val;
   ptrdiff_t char_offset = coding->produced_char;
   ptrdiff_t last_offset = char_offset;
   int last_id = charset_ascii;
-  int eol_dos =
-    !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
+  bool eol_dos
+    = !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
   int byte_after_cr = -1;
 
   CODING_GET_INFO (coding, attrs, charset_list);
@@ -4957,13 +4873,12 @@ decode_coding_big5 (struct coding_system *coding)
    `japanese-jisx0208', `chinese-big5-1', and `chinese-big5-2'.  We
    are sure that all these charsets are registered as official charset
    (i.e. do not have extended leading-codes).  Characters of other
-   charsets are produced without any encoding.  If SJIS_P is 1, encode
-   SJIS text, else encode BIG5 text.  */
+   charsets are produced without any encoding.  */
 
-static int
+static bool
 encode_coding_sjis (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
@@ -4971,7 +4886,7 @@ encode_coding_sjis (struct coding_system *coding)
   int safe_room = 4;
   ptrdiff_t produced_chars = 0;
   Lisp_Object attrs, charset_list, val;
-  int ascii_compatible;
+  bool ascii_compatible;
   struct charset *charset_kanji, *charset_kana;
   struct charset *charset_kanji2;
   int c;
@@ -5054,10 +4969,10 @@ encode_coding_sjis (struct coding_system *coding)
   return 0;
 }
 
-static int
+static bool
 encode_coding_big5 (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
@@ -5065,7 +4980,7 @@ encode_coding_big5 (struct coding_system *coding)
   int safe_room = 4;
   ptrdiff_t produced_chars = 0;
   Lisp_Object attrs, charset_list, val;
-  int ascii_compatible;
+  bool ascii_compatible;
   struct charset *charset_big5;
   int c;
 
@@ -5130,17 +5045,16 @@ encode_coding_big5 (struct coding_system *coding)
 /*** 10. CCL handlers ***/
 
 /* See the above "GENERAL NOTES on `detect_coding_XXX ()' functions".
-   Check if a text is encoded in a coding system of which
-   encoder/decoder are written in CCL program.  If it is, return
-   CATEGORY_MASK_CCL, else return 0.  */
+   Return true if a text is encoded in a coding system of which
+   encoder/decoder are written in CCL program.  */
 
-static int
+static bool
 detect_coding_ccl (struct coding_system *coding,
                    struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source, *src_base;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   ptrdiff_t consumed_chars = 0;
   int found = 0;
   unsigned char *valids;
@@ -5182,7 +5096,7 @@ decode_coding_ccl (struct coding_system *coding)
   int *charbuf = coding->charbuf + coding->charbuf_used;
   int *charbuf_end = coding->charbuf + coding->charbuf_size;
   ptrdiff_t consumed_chars = 0;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   struct ccl_program *ccl = &coding->spec.ccl->ccl;
   int source_charbuf[1024];
   int source_byteidx[1025];
@@ -5243,11 +5157,11 @@ decode_coding_ccl (struct coding_system *coding)
   coding->charbuf_used = charbuf - coding->charbuf;
 }
 
-static int
+static bool
 encode_coding_ccl (struct coding_system *coding)
 {
   struct ccl_program *ccl = &coding->spec.ccl->ccl;
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
@@ -5308,7 +5222,6 @@ encode_coding_ccl (struct coding_system *coding)
   return 0;
 }
 
-
 
 /*** 10, 11. no-conversion handlers ***/
 
@@ -5317,8 +5230,8 @@ encode_coding_ccl (struct coding_system *coding)
 static void
 decode_coding_raw_text (struct coding_system *coding)
 {
-  int eol_dos =
-    !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
+  bool eol_dos
+    = !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
 
   coding->chars_at_source = 1;
   coding->consumed_char = coding->src_chars;
@@ -5333,10 +5246,10 @@ decode_coding_raw_text (struct coding_system *coding)
     record_conversion_result (coding, CODING_RESULT_SUCCESS);
 }
 
-static int
+static bool
 encode_coding_raw_text (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = coding->charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
@@ -5414,21 +5327,20 @@ encode_coding_raw_text (struct coding_system *coding)
 }
 
 /* See the above "GENERAL NOTES on `detect_coding_XXX ()' functions".
-   Check if a text is encoded in a charset-based coding system.  If it
-   is, return 1, else return 0.  */
+   Return true if a text is encoded in a charset-based coding system.  */
 
-static int
+static bool
 detect_coding_charset (struct coding_system *coding,
                        struct coding_detection_info *detect_info)
 {
   const unsigned char *src = coding->source, *src_base;
   const unsigned char *src_end = coding->source + coding->src_bytes;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   ptrdiff_t consumed_chars = 0;
   Lisp_Object attrs, valids, name;
   int found = 0;
   ptrdiff_t head_ascii = coding->head_ascii;
-  int check_latin_extra = 0;
+  bool check_latin_extra = 0;
 
   detect_info->checked |= CATEGORY_MASK_CHARSET;
 
@@ -5532,14 +5444,14 @@ decode_coding_charset (struct coding_system *coding)
   int *charbuf_end
     = coding->charbuf + coding->charbuf_size - (MAX_ANNOTATION_LENGTH * 2);
   ptrdiff_t consumed_chars = 0, consumed_chars_base;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   Lisp_Object attrs = CODING_ID_ATTRS (coding->id);
   Lisp_Object valids;
   ptrdiff_t char_offset = coding->produced_char;
   ptrdiff_t last_offset = char_offset;
   int last_id = charset_ascii;
-  int eol_dos =
-    !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
+  bool eol_dos
+    = !inhibit_eol_conversion && EQ (CODING_ID_EOL_TYPE (coding->id), Qdos);
   int byte_after_cr = -1;
 
   valids = AREF (attrs, coding_attr_charset_valids);
@@ -5648,10 +5560,10 @@ decode_coding_charset (struct coding_system *coding)
   coding->charbuf_used = charbuf - coding->charbuf;
 }
 
-static int
+static bool
 encode_coding_charset (struct coding_system *coding)
 {
-  int multibytep = coding->dst_multibyte;
+  bool multibytep = coding->dst_multibyte;
   int *charbuf = coding->charbuf;
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
@@ -5659,7 +5571,7 @@ encode_coding_charset (struct coding_system *coding)
   int safe_room = MAX_MULTIBYTE_LENGTH;
   ptrdiff_t produced_chars = 0;
   Lisp_Object attrs, charset_list;
-  int ascii_compatible;
+  bool ascii_compatible;
   int c;
 
   CODING_GET_INFO (coding, attrs, charset_list);
@@ -5865,7 +5777,6 @@ setup_coding_system (Lisp_Object coding_system, struct coding_system *coding)
       coding->encoder = encode_coding_emacs_mule;
       coding->common_flags
         |= (CODING_REQUIRE_DECODING_MASK | CODING_REQUIRE_ENCODING_MASK);
-      coding->spec.emacs_mule.full_support = 1;
       if (! NILP (AREF (attrs, coding_attr_emacs_mule_full))
           && ! EQ (CODING_ATTR_CHARSET_LIST (attrs), Vemacs_mule_charset_list))
         {
@@ -5883,7 +5794,6 @@ setup_coding_system (Lisp_Object coding_system, struct coding_system *coding)
             SSET (safe_charsets, XFASTINT (XCAR (tail)), 0);
           coding->max_charset_id = max_charset_id;
           coding->safe_charsets = SDATA (safe_charsets);
-          coding->spec.emacs_mule.full_support = 1;
         }
       coding->spec.emacs_mule.cmp_status.state = COMPOSING_NO;
       coding->spec.emacs_mule.cmp_status.method = COMPOSITION_NO;
@@ -6216,11 +6126,9 @@ detect_eol (const unsigned char *source, ptrdiff_t src_bytes,
 
   if ((1 << category) & CATEGORY_MASK_UTF_16)
     {
-      int msb, lsb;
-
-      msb = category == (coding_category_utf_16_le
-                         | coding_category_utf_16_le_nosig);
-      lsb = 1 - msb;
+      bool msb = category == (coding_category_utf_16_le
+                              | coding_category_utf_16_le_nosig);
+      bool lsb = !msb;
 
       while (src + 1 < src_end)
         {
@@ -6335,7 +6243,7 @@ static void
 detect_coding (struct coding_system *coding)
 {
   const unsigned char *src, *src_end;
-  int saved_mode = coding->mode;
+  unsigned int saved_mode = coding->mode;
 
   coding->consumed = coding->consumed_char = 0;
   coding->produced = coding->produced_char = 0;
@@ -6350,7 +6258,7 @@ detect_coding (struct coding_system *coding)
     {
       int c, i;
       struct coding_detection_info detect_info;
-      int null_byte_found = 0, eight_bit_found = 0;
+      bool null_byte_found = 0, eight_bit_found = 0;
 
       detect_info.checked = detect_info.found = detect_info.rejected = 0;
       for (src = coding->source; src < src_end; src++)
@@ -6609,11 +6517,11 @@ decode_eol (struct coding_system *coding)
 
 
 /* Return a translation table (or list of them) from coding system
-   attribute vector ATTRS for encoding (ENCODEP is nonzero) or
-   decoding (ENCODEP is zero). */
+   attribute vector ATTRS for encoding (if ENCODEP) or decoding (if
+   not ENCODEP). */
 
 static Lisp_Object
-get_translation_table (Lisp_Object attrs, int encodep, int *max_lookup)
+get_translation_table (Lisp_Object attrs, bool encodep, int *max_lookup)
 {
   Lisp_Object standard, translation_table;
   Lisp_Object val;
@@ -6743,7 +6651,7 @@ get_translation (Lisp_Object trans, int *buf, int *buf_end)
 
 static int
 produce_chars (struct coding_system *coding, Lisp_Object translation_table,
-               int last_block)
+               bool last_block)
 {
   unsigned char *dst = coding->destination + coding->produced;
   unsigned char *dst_end = coding->destination + coding->dst_bytes;
@@ -6846,7 +6754,7 @@ produce_chars (struct coding_system *coding, Lisp_Object translation_table,
         {
           if (coding->src_multibyte)
             {
-              int multibytep = 1;
+              bool multibytep = 1;
               ptrdiff_t consumed_chars = 0;
 
               while (1)
@@ -6882,7 +6790,7 @@ produce_chars (struct coding_system *coding, Lisp_Object translation_table,
           else
             while (src < src_end)
               {
-                int multibytep = 1;
+                bool multibytep = 1;
                 int c = *src++;
 
                 if (dst >= dst_end - 1)
@@ -7018,7 +6926,7 @@ produce_charset (struct coding_system *coding, int *charbuf, ptrdiff_t pos)
     if (! coding->charbuf)                                              \
       {                                                                 \
         record_conversion_result (coding, CODING_RESULT_INSUFFICIENT_MEM); \
-        return coding->result;                                          \
+        return;                                                         \
       }                                                                 \
     coding->charbuf_size = size;                                        \
   } while (0)
@@ -7079,7 +6987,7 @@ produce_annotation (struct coding_system *coding, ptrdiff_t pos)
    CODING->dst_object.
 */
 
-static int
+static void
 decode_coding (struct coding_system *coding)
 {
   Lisp_Object attrs;
@@ -7098,8 +7006,7 @@ decode_coding (struct coding_system *coding)
   undo_list = Qt;
   if (BUFFERP (coding->dst_object))
     {
-      if (current_buffer != XBUFFER (coding->dst_object))
-        set_buffer_internal (XBUFFER (coding->dst_object));
+      set_buffer_internal (XBUFFER (coding->dst_object));
       if (GPT != PT)
         move_gap_both (PT, PT_BYTE);
 
@@ -7212,7 +7119,6 @@ decode_coding (struct coding_system *coding)
       bset_undo_list (current_buffer, undo_list);
       record_insert (coding->dst_pos, coding->produced_char);
     }
-  return coding->result;
 }
 
 
@@ -7341,7 +7247,7 @@ consume_chars (struct coding_system *coding, Lisp_Object translation_table,
   const unsigned char *src_end = coding->source + coding->src_bytes;
   ptrdiff_t pos = coding->src_pos + coding->consumed_char;
   ptrdiff_t end_pos = coding->src_pos + coding->src_chars;
-  int multibytep = coding->src_multibyte;
+  bool multibytep = coding->src_multibyte;
   Lisp_Object eol_type;
   int c;
   ptrdiff_t stop, stop_composition, stop_charset;
@@ -7488,7 +7394,7 @@ consume_chars (struct coding_system *coding, Lisp_Object translation_table,
    If CODING->dst_object is nil, the encoded data is placed at the
    memory area specified by CODING->destination.  */
 
-static int
+static void
 encode_coding (struct coding_system *coding)
 {
   Lisp_Object attrs;
@@ -7530,8 +7436,6 @@ encode_coding (struct coding_system *coding)
 
   if (BUFFERP (coding->dst_object) && coding->produced_char > 0)
     insert_from_gap (coding->produced_char, coding->produced);
-
-  return (coding->result);
 }
 
 
@@ -7545,26 +7449,27 @@ static Lisp_Object Vcode_conversion_workbuf_name;
    versions of Vcode_conversion_workbuf_name.  */
 static Lisp_Object Vcode_conversion_reused_workbuf;
 
-/* 1 iff Vcode_conversion_reused_workbuf is already in use.  */
-static int reused_workbuf_in_use;
+/* True iff Vcode_conversion_reused_workbuf is already in use.  */
+static bool reused_workbuf_in_use;
 
 
 /* Return a working buffer of code conversion.  MULTIBYTE specifies the
    multibyteness of returning buffer.  */
 
 static Lisp_Object
-make_conversion_work_buffer (int multibyte)
+make_conversion_work_buffer (bool multibyte)
 {
   Lisp_Object name, workbuf;
   struct buffer *current;
 
-  if (reused_workbuf_in_use++)
+  if (reused_workbuf_in_use)
     {
       name = Fgenerate_new_buffer_name (Vcode_conversion_workbuf_name, Qnil);
       workbuf = Fget_buffer_create (name);
     }
   else
     {
+      reused_workbuf_in_use = 1;
       if (NILP (Fbuffer_live_p (Vcode_conversion_reused_workbuf)))
         Vcode_conversion_reused_workbuf
           = Fget_buffer_create (Vcode_conversion_workbuf_name);
@@ -7606,7 +7511,7 @@ code_conversion_restore (Lisp_Object arg)
 }
 
 Lisp_Object
-code_conversion_save (int with_work_buf, int multibyte)
+code_conversion_save (bool with_work_buf, bool multibyte)
 {
   Lisp_Object workbuf = Qnil;
 
@@ -7617,7 +7522,7 @@ code_conversion_save (int with_work_buf, int multibyte)
   return workbuf;
 }
 
-int
+void
 decode_coding_gap (struct coding_system *coding,
                    ptrdiff_t chars, ptrdiff_t bytes)
 {
@@ -7660,7 +7565,6 @@ decode_coding_gap (struct coding_system *coding,
     }
 
   unbind_to (count, Qnil);
-  return coding->result;
 }
 
 
@@ -7706,8 +7610,8 @@ decode_coding_object (struct coding_system *coding,
   ptrdiff_t chars = to - from;
   ptrdiff_t bytes = to_byte - from_byte;
   Lisp_Object attrs;
-  int saved_pt = -1, saved_pt_byte IF_LINT (= 0);
-  int need_marker_adjustment = 0;
+  ptrdiff_t saved_pt = -1, saved_pt_byte IF_LINT (= 0);
+  bool need_marker_adjustment = 0;
   Lisp_Object old_deactivate_mark;
 
   old_deactivate_mark = Vdeactivate_mark;
@@ -7894,9 +7798,9 @@ encode_coding_object (struct coding_system *coding,
   ptrdiff_t chars = to - from;
   ptrdiff_t bytes = to_byte - from_byte;
   Lisp_Object attrs;
-  int saved_pt = -1, saved_pt_byte IF_LINT (= 0);
-  int need_marker_adjustment = 0;
-  int kill_src_buffer = 0;
+  ptrdiff_t saved_pt = -1, saved_pt_byte IF_LINT (= 0);
+  bool need_marker_adjustment = 0;
+  bool kill_src_buffer = 0;
   Lisp_Object old_deactivate_mark;
 
   old_deactivate_mark = Vdeactivate_mark;
@@ -8172,10 +8076,10 @@ function `define-coding-system'.  */)
 
 
 /* Detect how the bytes at SRC of length SRC_BYTES are encoded.  If
-   HIGHEST is nonzero, return the coding system of the highest
+   HIGHEST, return the coding system of the highest
    priority among the detected coding systems.  Otherwise return a
    list of detected coding systems sorted by their priorities.  If
-   MULTIBYTEP is nonzero, it is assumed that the bytes are in correct
+   MULTIBYTEP, it is assumed that the bytes are in correct
    multibyte form but contains only ASCII and eight-bit chars.
    Otherwise, the bytes are raw bytes.
 
@@ -8190,7 +8094,7 @@ function `define-coding-system'.  */)
 Lisp_Object
 detect_coding_system (const unsigned char *src,
                       ptrdiff_t src_chars, ptrdiff_t src_bytes,
-                      int highest, int multibytep,
+                      bool highest, bool multibytep,
                       Lisp_Object coding_system)
 {
   const unsigned char *src_end = src + src_bytes;
@@ -8200,7 +8104,7 @@ detect_coding_system (const unsigned char *src,
   ptrdiff_t id;
   struct coding_detection_info detect_info;
   enum coding_category base_category;
-  int null_byte_found = 0, eight_bit_found = 0;
+  bool null_byte_found = 0, eight_bit_found = 0;
 
   if (NILP (coding_system))
     coding_system = Qundecided;
@@ -8556,7 +8460,7 @@ highest priority.  */)
 }
 
 
-static inline int
+static inline bool
 char_encodable_p (int c, Lisp_Object attrs)
 {
   Lisp_Object tail;
@@ -8728,7 +8632,7 @@ to the string.  */)
   Lisp_Object positions;
   ptrdiff_t from, to;
   const unsigned char *p, *stop, *pend;
-  int ascii_compatible;
+  bool ascii_compatible;
 
   setup_coding_system (Fcheck_coding_system (coding_system), &coding);
   attrs = CODING_ID_ATTRS (coding.id);
@@ -8952,7 +8856,7 @@ is nil.  */)
 static Lisp_Object
 code_convert_region (Lisp_Object start, Lisp_Object end,
                      Lisp_Object coding_system, Lisp_Object dst_object,
-                     int encodep, int norecord)
+                     bool encodep, bool norecord)
 {
   struct coding_system coding;
   ptrdiff_t from, from_byte, to, to_byte;
@@ -9040,7 +8944,8 @@ not fully specified.)  */)
 
 Lisp_Object
 code_convert_string (Lisp_Object string, Lisp_Object coding_system,
-                     Lisp_Object dst_object, int encodep, int nocopy, int norecord)
+                     Lisp_Object dst_object, bool encodep, bool nocopy,
+                     bool norecord)
 {
   struct coding_system coding;
   ptrdiff_t chars, bytes;
@@ -9088,7 +8993,7 @@ code_convert_string (Lisp_Object string, Lisp_Object coding_system,
 
 Lisp_Object
 code_convert_string_norecord (Lisp_Object string, Lisp_Object coding_system,
-                              int encodep)
+                              bool encodep)
 {
   return code_convert_string (string, coding_system, Qt, encodep, 0, 1);
 }
@@ -9489,7 +9394,7 @@ usage: (set-coding-system-priority &rest coding-systems)  */)
   (ptrdiff_t nargs, Lisp_Object *args)
 {
   ptrdiff_t i, j;
-  int changed[coding_category_max];
+  bool changed[coding_category_max];
   enum coding_category priorities[coding_category_max];
 
   memset (changed, 0, sizeof changed);
diff --git a/src/coding.h b/src/coding.h
index 2987f19607b..c45d2ef86e2 100644
--- a/src/coding.h
+++ b/src/coding.h
@@ -321,7 +321,7 @@ struct composition_status
 {
   enum composition_state state;
   enum composition_method method;
-  int old_form;           /* 0:pre-21 form, 1:post-21 form */
+  bool old_form;          /* true if pre-21 form */
   int length;             /* number of elements produced in charbuf */
   int nchars;             /* number of characters composed */
   int ncomps;             /* number of composition components */
@@ -350,18 +350,18 @@ struct iso_2022_spec
      there was an invalid designation previously.  */
   int current_designation[4];
 
-  /* Set to 1 temporarily only when graphic register 2 or 3 is invoked
-     by single-shift while encoding.  */
-  int single_shifting;
-
-  /* Set to 1 temporarily only when processing at beginning of line.  */
-  int bol;
-
   /* If positive, we are now scanning CTEXT extended segment.  */
   int ctext_extended_segment_len;
 
-  /* If nonzero, we are now scanning embedded UTF-8 sequence.  */
-  int embedded_utf_8;
+  /* True temporarily only when graphic register 2 or 3 is invoked by
+     single-shift while encoding.  */
+  unsigned single_shifting : 1;
+
+  /* True temporarily only when processing at beginning of line.  */
+  unsigned bol : 1;
+
+  /* If true, we are now scanning embedded UTF-8 sequence.  */
+  unsigned embedded_utf_8 : 1;
 
   /* The current composition.  */
   struct composition_status cmp_status;
@@ -369,7 +369,6 @@ struct iso_2022_spec
 
 struct emacs_mule_spec
 {
-  int full_support;
   struct composition_status cmp_status;
 };
 
@@ -470,10 +469,6 @@ struct coding_system
   Lisp_Object dst_object;
   unsigned char *destination;
 
-  /* Set to 1 if the source of conversion is not in the member
-     `charbuf', but at `src_object'.  */
-  int chars_at_source;
-
   /* If an element is non-negative, it is a character code.
 
      If it is in the range -128..-1, it is a 8-bit character code
@@ -489,18 +484,21 @@ struct coding_system
   int *charbuf;
   int charbuf_size, charbuf_used;
 
+  /* True if the source of conversion is not in the member
+     `charbuf', but at `src_object'.  */
+  unsigned chars_at_source : 1;
+
   /* Set to 1 if charbuf contains an annotation.  */
-  int annotated;
+  unsigned annotated : 1;
 
   unsigned char carryover[64];
   int carryover_bytes;
 
   int default_char;
 
-  int (*detector) (struct coding_system *,
-                   struct coding_detection_info *);
+  bool (*detector) (struct coding_system *, struct coding_detection_info *);
   void (*decoder) (struct coding_system *);
-  int (*encoder) (struct coding_system *);
+  bool (*encoder) (struct coding_system *);
 };
 
 /* Meanings of bits in the member `common_flags' of the structure
@@ -688,22 +686,20 @@ struct coding_system
 #define ENCODE_UTF_8(str) code_convert_string_norecord (str, Qutf_8, 1)
 
 /* Extern declarations.  */
-extern Lisp_Object code_conversion_save (int, int);
-extern int decoding_buffer_size (struct coding_system *, int);
-extern int encoding_buffer_size (struct coding_system *, int);
+extern Lisp_Object code_conversion_save (bool, bool);
 extern void setup_coding_system (Lisp_Object, struct coding_system *);
 extern Lisp_Object coding_charset_list (struct coding_system *);
 extern Lisp_Object coding_system_charset_list (Lisp_Object);
 extern Lisp_Object code_convert_string (Lisp_Object, Lisp_Object,
-                                        Lisp_Object, int, int, int);
+                                        Lisp_Object, bool, bool, bool);
 extern Lisp_Object code_convert_string_norecord (Lisp_Object, Lisp_Object,
-                                                 int);
+                                                 bool);
 extern Lisp_Object raw_text_coding_system (Lisp_Object);
 extern Lisp_Object coding_inherit_eol_type (Lisp_Object, Lisp_Object);
 extern Lisp_Object complement_process_encoding_system (Lisp_Object);
 
-extern int decode_coding_gap (struct coding_system *,
-                              ptrdiff_t, ptrdiff_t);
+extern void decode_coding_gap (struct coding_system *,
+                               ptrdiff_t, ptrdiff_t);
 extern void decode_coding_object (struct coding_system *,
                                   Lisp_Object, ptrdiff_t, ptrdiff_t,
                                   ptrdiff_t, ptrdiff_t, Lisp_Object);
@@ -778,6 +774,5 @@ extern struct coding_system safe_terminal_coding;
 extern Lisp_Object Qcoding_system_error;
 
 extern char emacs_mule_bytes[256];
-extern int emacs_mule_string_char (unsigned char *);
 
 #endif /* EMACS_CODING_H */
diff --git a/src/composite.c b/src/composite.c
index 4e90e9bb914..eddabb66d33 100644
--- a/src/composite.c
+++ b/src/composite.c
@@ -428,7 +428,7 @@ get_composition_id (ptrdiff_t charpos, ptrdiff_t bytepos, ptrdiff_t nchars,
 
    This doesn't check the validity of composition.  */
 
-int
+bool
 find_composition (ptrdiff_t pos, ptrdiff_t limit,
                   ptrdiff_t *start, ptrdiff_t *end,
                   Lisp_Object *prop, Lisp_Object object)
@@ -709,7 +709,7 @@ static Lisp_Object fill_gstring_header (Lisp_Object, Lisp_Object,
                                         Lisp_Object, Lisp_Object,
                                         Lisp_Object);
 
-int
+bool
 composition_gstring_p (Lisp_Object gstring)
 {
   Lisp_Object header;
@@ -1212,11 +1212,13 @@ composition_compute_stop_pos (struct composition_it *cmp_it, ptrdiff_t charpos,
    string.  In that case, FACE must not be NULL.
 
    If the character is composed, setup members of CMP_IT (id, nglyphs,
-   from, to, reversed_p), and return 1.  Otherwise, update
-   CMP_IT->stop_pos, and return 0.  */
+   from, to, reversed_p), and return true.  Otherwise, update
+   CMP_IT->stop_pos, and return false.  */
 
-int
-composition_reseat_it (struct composition_it *cmp_it, ptrdiff_t charpos, ptrdiff_t bytepos, ptrdiff_t endpos, struct window *w, struct face *face, Lisp_Object string)
+bool
+composition_reseat_it (struct composition_it *cmp_it, ptrdiff_t charpos,
+                       ptrdiff_t bytepos, ptrdiff_t endpos, struct window *w,
+                       struct face *face, Lisp_Object string)
 {
   if (endpos < 0)
     endpos = NILP (string) ? BEGV : 0;
@@ -1482,10 +1484,10 @@ struct position_record
 /* This is like find_composition, but find an automatic composition
    instead.  It is assured that POS is not within a static
    composition.  If found, set *GSTRING to the glyph-string
-   representing the composition, and return 1.  Otherwise, *GSTRING to
-   Qnil, and return 0.  */
+   representing the composition, and return true.  Otherwise, *GSTRING to
+   Qnil, and return false.  */
 
-static int
+static bool
 find_automatic_composition (ptrdiff_t pos, ptrdiff_t limit,
                             ptrdiff_t *start, ptrdiff_t *end,
                             Lisp_Object *gstring, Lisp_Object string)
@@ -1498,7 +1500,7 @@ find_automatic_composition (ptrdiff_t pos, ptrdiff_t limit,
   int c;
   Lisp_Object window;
   struct window *w;
-  int need_adjustment = 0;
+  bool need_adjustment = 0;
 
   window = Fget_buffer_window (Fcurrent_buffer (), Qnil);
   if (NILP (window))
diff --git a/src/composite.h b/src/composite.h
index 6a7e0a5e2c7..68f5b27ee42 100644
--- a/src/composite.h
+++ b/src/composite.h
@@ -223,8 +223,8 @@ extern Lisp_Object Qcomposition;
 extern Lisp_Object composition_hash_table;
 extern ptrdiff_t get_composition_id (ptrdiff_t, ptrdiff_t, ptrdiff_t,
                                      Lisp_Object, Lisp_Object);
-extern int find_composition (ptrdiff_t, ptrdiff_t, ptrdiff_t *, ptrdiff_t *,
-                             Lisp_Object *, Lisp_Object);
+extern bool find_composition (ptrdiff_t, ptrdiff_t, ptrdiff_t *, ptrdiff_t *,
+                              Lisp_Object *, Lisp_Object);
 extern void update_compositions (ptrdiff_t, ptrdiff_t, int);
 extern void make_composition_value_copy (Lisp_Object);
 extern void compose_region (int, int, Lisp_Object, Lisp_Object,
@@ -310,17 +310,16 @@ struct font_metrics;
 
 extern Lisp_Object composition_gstring_put_cache (Lisp_Object, ptrdiff_t);
 extern Lisp_Object composition_gstring_from_id (ptrdiff_t);
-extern int composition_gstring_p (Lisp_Object);
+extern bool composition_gstring_p (Lisp_Object);
 extern int composition_gstring_width (Lisp_Object, ptrdiff_t, ptrdiff_t,
                                       struct font_metrics *);
 
 extern void composition_compute_stop_pos (struct composition_it *,
                                           ptrdiff_t, ptrdiff_t, ptrdiff_t,
                                           Lisp_Object);
-extern int composition_reseat_it (struct composition_it *,
-                                  ptrdiff_t, ptrdiff_t, ptrdiff_t,
-                                  struct window *, struct face *,
-                                  Lisp_Object);
+extern bool composition_reseat_it (struct composition_it *, ptrdiff_t,
+                                   ptrdiff_t, ptrdiff_t, struct window *,
+                                   struct face *, Lisp_Object);
 extern int composition_update_it (struct composition_it *,
                                   ptrdiff_t, ptrdiff_t, Lisp_Object);
 
diff --git a/src/data.c b/src/data.c
index f812c280b40..d8b7f42ea3f 100644
--- a/src/data.c
+++ b/src/data.c
@@ -83,8 +83,8 @@ Lisp_Object Qoverflow_error, Qunderflow_error;
 Lisp_Object Qfloatp;
 Lisp_Object Qnumberp, Qnumber_or_marker_p;
 
-Lisp_Object Qinteger, Qinterval, Qfloat, Qvector;
-Lisp_Object Qsymbol, Qstring, Qcons, Qmisc;
+Lisp_Object Qinteger, Qsymbol;
+static Lisp_Object Qcons, Qfloat, Qmisc, Qstring, Qvector;
 Lisp_Object Qwindow;
 static Lisp_Object Qoverlay, Qwindow_configuration;
 static Lisp_Object Qprocess, Qmarker;
@@ -1080,10 +1080,10 @@ DEFUN ("set", Fset, Sset, 2, 2, 0,
   return newval;
 }
 
-/* Return 1 if SYMBOL currently has a let-binding
+/* Return true if SYMBOL currently has a let-binding
    which was made in the buffer that is now current.  */
 
-static int
+static bool
 let_shadows_buffer_binding_p (struct Lisp_Symbol *symbol)
 {
   struct specbinding *p;
@@ -1102,7 +1102,7 @@ let_shadows_buffer_binding_p (struct Lisp_Symbol *symbol)
   return 0;
 }
 
-static int
+static bool
 let_shadows_global_binding_p (Lisp_Object symbol)
 {
   struct specbinding *p;
@@ -1118,14 +1118,15 @@ let_shadows_global_binding_p (Lisp_Object symbol)
    If buffer/frame-locality is an issue, WHERE specifies which context to use.
    (nil stands for the current buffer/frame).
 
-   If BINDFLAG is zero, then if this symbol is supposed to become
+   If BINDFLAG is false, then if this symbol is supposed to become
    local in every buffer where it is set, then we make it local.
-   If BINDFLAG is nonzero, we don't do that.  */
+   If BINDFLAG is true, we don't do that.  */
 
 void
-set_internal (register Lisp_Object symbol, register Lisp_Object newval, register Lisp_Object where, int bindflag)
+set_internal (Lisp_Object symbol, Lisp_Object newval, Lisp_Object where,
+              bool bindflag)
 {
-  int voide = EQ (newval, Qunbound);
+  bool voide = EQ (newval, Qunbound);
   struct Lisp_Symbol *sym;
   Lisp_Object tem1;
 
@@ -1464,7 +1465,8 @@ union Lisp_Val_Fwd
   };
 
 static struct Lisp_Buffer_Local_Value *
-make_blv (struct Lisp_Symbol *sym, int forwarded, union Lisp_Val_Fwd valcontents)
+make_blv (struct Lisp_Symbol *sym, bool forwarded,
+          union Lisp_Val_Fwd valcontents)
 {
   struct Lisp_Buffer_Local_Value *blv = xmalloc (sizeof *blv);
   Lisp_Object symbol;
@@ -1508,7 +1510,7 @@ The function `default-value' gets the default value and `set-default' sets it.
   struct Lisp_Symbol *sym;
   struct Lisp_Buffer_Local_Value *blv = NULL;
   union Lisp_Val_Fwd valcontents IF_LINT (= {LISP_INITIALLY_ZERO});
-  int forwarded IF_LINT (= 0);
+  bool forwarded IF_LINT (= 0);
 
   CHECK_SYMBOL (variable);
   sym = XSYMBOL (variable);
@@ -1580,10 +1582,10 @@ See also `make-variable-buffer-local'.
 
 Do not use `make-local-variable' to make a hook variable buffer-local.
 Instead, use `add-hook' and specify t for the LOCAL argument.  */)
-  (register Lisp_Object variable)
+  (Lisp_Object variable)
 {
-  register Lisp_Object tem;
-  int forwarded IF_LINT (= 0);
+  Lisp_Object tem;
+  bool forwarded IF_LINT (= 0);
   union Lisp_Val_Fwd valcontents IF_LINT (= {LISP_INITIALLY_ZERO});
   struct Lisp_Symbol *sym;
   struct Lisp_Buffer_Local_Value *blv = NULL;
@@ -1767,9 +1769,9 @@ is to set the VARIABLE frame parameter of that frame.  See
 Note that since Emacs 23.1, variables cannot be both buffer-local and
 frame-local any more (buffer-local bindings used to take precedence over
 frame-local bindings).  */)
-  (register Lisp_Object variable)
+  (Lisp_Object variable)
 {
-  int forwarded;
+  bool forwarded;
   union Lisp_Val_Fwd valcontents;
   struct Lisp_Symbol *sym;
   struct Lisp_Buffer_Local_Value *blv = NULL;
@@ -2225,7 +2227,7 @@ static Lisp_Object
 arithcompare (Lisp_Object num1, Lisp_Object num2, enum comparison comparison)
 {
   double f1 = 0, f2 = 0;
-  int floatp = 0;
+  bool floatp = 0;
 
   CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (num1);
   CHECK_NUMBER_OR_FLOAT_COERCE_MARKER (num2);
@@ -2342,7 +2344,7 @@ DEFUN ("zerop", Fzerop, Szerop, 1, 1, 0,
 uintmax_t
 cons_to_unsigned (Lisp_Object c, uintmax_t max)
 {
-  int valid = 0;
+  bool valid = 0;
   uintmax_t val IF_LINT (= 0);
   if (INTEGERP (c))
     {
@@ -2395,7 +2397,7 @@ cons_to_unsigned (Lisp_Object c, uintmax_t max)
 intmax_t
 cons_to_signed (Lisp_Object c, intmax_t min, intmax_t max)
 {
-  int valid = 0;
+  bool valid = 0;
   intmax_t val IF_LINT (= 0);
   if (INTEGERP (c))
     {
@@ -2513,14 +2515,11 @@ static Lisp_Object float_arith_driver (double, ptrdiff_t, enum arithop,
 static Lisp_Object
 arith_driver (enum arithop code, ptrdiff_t nargs, Lisp_Object *args)
 {
-  register Lisp_Object val;
-  ptrdiff_t argnum;
-  register EMACS_INT accum = 0;
-  register EMACS_INT next;
-
-  int overflow = 0;
-  ptrdiff_t ok_args;
-  EMACS_INT ok_accum;
+  Lisp_Object val;
+  ptrdiff_t argnum, ok_args;
+  EMACS_INT accum = 0;
+  EMACS_INT next, ok_accum;
+  bool overflow = 0;
 
   switch (code)
     {
@@ -3090,8 +3089,6 @@ syms_of_data (void)
   DEFSYM (Qchar_table, "char-table");
   DEFSYM (Qbool_vector, "bool-vector");
   DEFSYM (Qhash_table, "hash-table");
-  /* Used by Fgarbage_collect.  */
-  DEFSYM (Qinterval, "interval");
   DEFSYM (Qmisc, "misc");
 
   DEFSYM (Qdefun, "defun");
diff --git a/src/dbusbind.c b/src/dbusbind.c
index f63f2948304..901820648cb 100644
--- a/src/dbusbind.c
+++ b/src/dbusbind.c
@@ -70,7 +70,7 @@ static Lisp_Object QCdbus_registered_signal;
 static Lisp_Object xd_registered_buses;
 
 /* Whether we are reading a D-Bus event.  */
-static int xd_in_read_queued_messages = 0;
+static bool xd_in_read_queued_messages = 0;
 
 
 /* We use "xd_" and "XD_" as prefix for all internal symbols, because
@@ -997,8 +997,7 @@ xd_find_watch_fd (DBusWatch *watch)
 }
 
 /* Prototype.  */
-static void
-xd_read_queued_messages (int fd, void *data, int for_read);
+static void xd_read_queued_messages (int fd, void *data);
 
 /* Start monitoring WATCH for possible I/O.  */
 static dbus_bool_t
@@ -1686,7 +1685,7 @@ xd_read_message (Lisp_Object bus)
 
 /* Callback called when something is ready to read or write.  */
 static void
-xd_read_queued_messages (int fd, void *data, int for_read)
+xd_read_queued_messages (int fd, void *data)
 {
   Lisp_Object busp = xd_registered_buses;
   Lisp_Object bus = Qnil;
diff --git a/src/dired.c b/src/dired.c
index 771230717e3..fa293258107 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -109,18 +109,20 @@ directory_files_internal_unwind (Lisp_Object dh)
 }
 
 /* Function shared by Fdirectory_files and Fdirectory_files_and_attributes.
-   When ATTRS is zero, return a list of directory filenames; when
-   non-zero, return a list of directory filenames and their attributes.
+   If not ATTRS, return a list of directory filenames;
+   if ATTRS, return a list of directory filenames and their attributes.
    In the latter case, ID_FORMAT is passed to Ffile_attributes.  */
 
 Lisp_Object
-directory_files_internal (Lisp_Object directory, Lisp_Object full, Lisp_Object match, Lisp_Object nosort, int attrs, Lisp_Object id_format)
+directory_files_internal (Lisp_Object directory, Lisp_Object full,
+                          Lisp_Object match, Lisp_Object nosort, bool attrs,
+                          Lisp_Object id_format)
 {
   DIR *d;
   ptrdiff_t directory_nbytes;
   Lisp_Object list, dirfilename, encoded_directory;
   struct re_pattern_buffer *bufp = NULL;
-  int needsep = 0;
+  bool needsep = 0;
   ptrdiff_t count = SPECPDL_INDEX ();
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
   DIRENTRY *dp;
@@ -227,7 +229,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full, Lisp_Object m
       if (DIRENTRY_NONEMPTY (dp))
         {
           ptrdiff_t len;
-          int wanted = 0;
+          bool wanted = 0;
           Lisp_Object name, finalname;
           struct gcpro gcpro1, gcpro2;
 
@@ -381,9 +383,8 @@ which see.  */)
 }
 
 
-static Lisp_Object file_name_completion
-  (Lisp_Object file, Lisp_Object dirname, int all_flag, int ver_flag,
-   Lisp_Object predicate);
+static Lisp_Object file_name_completion (Lisp_Object, Lisp_Object, bool,
+                                         Lisp_Object);
 
 DEFUN ("file-name-completion", Ffile_name_completion, Sfile_name_completion,
        2, 3, 0,
@@ -415,7 +416,7 @@ determined by the variable `completion-ignored-extensions', which see.  */)
   if (!NILP (handler))
     return call4 (handler, Qfile_name_completion, file, directory, predicate);
 
-  return file_name_completion (file, directory, 0, 0, predicate);
+  return file_name_completion (file, directory, 0, predicate);
 }
 
 DEFUN ("file-name-all-completions", Ffile_name_all_completions,
@@ -439,14 +440,15 @@ These are all file names in directory DIRECTORY which begin with FILE.  */)
   if (!NILP (handler))
     return call3 (handler, Qfile_name_all_completions, file, directory);
 
-  return file_name_completion (file, directory, 1, 0, Qnil);
+  return file_name_completion (file, directory, 1, Qnil);
 }
 
 static int file_name_completion_stat (Lisp_Object dirname, DIRENTRY *dp, struct stat *st_addr);
 static Lisp_Object Qdefault_directory;
 
 static Lisp_Object
-file_name_completion (Lisp_Object file, Lisp_Object dirname, int all_flag, int ver_flag, Lisp_Object predicate)
+file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag,
+                      Lisp_Object predicate)
 {
   DIR *d;
   ptrdiff_t bestmatchsize = 0;
@@ -458,11 +460,11 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, int all_flag, int v
   Lisp_Object encoded_file;
   Lisp_Object encoded_dir;
   struct stat st;
-  int directoryp;
-  /* If includeall is zero, exclude files in completion-ignored-extensions as
+  bool directoryp;
+  /* If not INCLUDEALL, exclude files in completion-ignored-extensions as
      well as "." and "..".  Until shown otherwise, assume we can't exclude
      anything.  */
-  int includeall = 1;
+  bool includeall = 1;
   ptrdiff_t count = SPECPDL_INDEX ();
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
 
@@ -500,7 +502,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, int all_flag, int v
     {
       DIRENTRY *dp;
       ptrdiff_t len;
-      int canexclude = 0;
+      bool canexclude = 0;
 
       errno = 0;
       dp = readdir (d);
@@ -528,7 +530,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, int all_flag, int v
       if (file_name_completion_stat (encoded_dir, dp, &st) < 0)
         continue;
 
-      directoryp = S_ISDIR (st.st_mode);
+      directoryp = S_ISDIR (st.st_mode) != 0;
       tem = Qnil;
       /* If all_flag is set, always include all.
          It would not actually be helpful to the user to ignore any possible
@@ -716,7 +718,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, int all_flag, int v
               /* This tests that the current file is an exact match
                  but BESTMATCH is not (it is too long).  */
               if ((matchsize == SCHARS (name)
-                   && matchsize + !!directoryp < SCHARS (bestmatch))
+                   && matchsize + directoryp < SCHARS (bestmatch))
                   ||
                   /* If there is no exact match ignoring case,
                      prefer a match that does not change the case
@@ -728,7 +730,7 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, int all_flag, int v
                      either both or neither are exact.  */
                   (((matchsize == SCHARS (name))
                     ==
-                    (matchsize + !!directoryp == SCHARS (bestmatch)))
+                    (matchsize + directoryp == SCHARS (bestmatch)))
                    && (cmp = Fcompare_strings (name, zero,
                                                make_number (SCHARS (file)),
                                                file, zero,
diff --git a/src/dispextern.h b/src/dispextern.h
index a25aac96df9..1140d98f8a7 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -671,7 +671,7 @@ struct glyph_matrix
 
   /* Values of BEGV and ZV as of last redisplay.  Set in
      mark_window_display_accurate_1.  */
-  int begv, zv;
+  ptrdiff_t begv, zv;
 };
 
 
@@ -1126,11 +1126,11 @@ struct glyph_row *matrix_row (struct glyph_matrix *, int);
       ((ROW)->phys_height - (ROW)->phys_ascent  \
        > (ROW)->height - (ROW)->ascent)
 
-/* Non-zero means that fonts have been loaded since the last glyph
+/* True means that fonts have been loaded since the last glyph
    matrix adjustments.  The function redisplay_internal adjusts glyph
-   matrices when this flag is non-zero.  */
+   matrices when this flag is true.  */
 
-extern int fonts_changed_p;
+extern bool fonts_changed_p;
 
 /* A glyph for a space.  */
 
@@ -1149,7 +1149,7 @@ extern int updated_area;
 /* Non-zero means last display completed.  Zero means it was
    preempted.  */
 
-extern int display_completed;
+extern bool display_completed;
 
 
 
@@ -1415,7 +1415,7 @@ struct glyph_string
       && !NILP (BVAR (XBUFFER (W->buffer), mode_line_format))   \
       && WINDOW_TOTAL_LINES (W) > 1)
 
-/* Value is non-zero if window W wants a header line.  */
+/* Value is true if window W wants a header line.  */
 
 #define WINDOW_WANTS_HEADER_LINE_P(W)                                   \
      (!MINI_WINDOW_P ((W))                                              \
@@ -1856,7 +1856,6 @@ struct bidi_it {
   int resolved_level;           /* final resolved level of this character */
   int invalid_levels;           /* how many PDFs to ignore */
   int invalid_rl_levels;        /* how many PDFs from RLE/RLO to ignore */
-  int prev_was_pdf;             /* if non-zero, previous char was PDF */
   struct bidi_saved_info prev;  /* info about previous character */
   struct bidi_saved_info last_strong; /* last-seen strong directional char */
   struct bidi_saved_info next_for_neutral; /* surrounding characters for... */
@@ -1879,6 +1878,7 @@ struct bidi_it {
   struct bidi_string_data string;       /* string to reorder */
   bidi_dir_t paragraph_dir;     /* current paragraph direction */
   ptrdiff_t separator_limit;    /* where paragraph separator should end */
+  unsigned prev_was_pdf : 1;    /* if non-zero, previous char was PDF */
   unsigned first_elt : 1;       /* if non-zero, examine current char first */
   unsigned new_paragraph : 1;   /* if non-zero, we expect a new paragraph */
   unsigned frame_window_p : 1;  /* non-zero if displaying on a GUI frame */
@@ -2085,10 +2085,10 @@ struct composition_it
   ptrdiff_t lookback;
   /* If non-negative, number of glyphs of the glyph-string.  */
   int nglyphs;
-  /* Nonzero iff the composition is created while buffer is scanned in
+  /* True iff the composition is created while buffer is scanned in
      reverse order, and thus the grapheme clusters must be rendered
      from the last to the first.  */
-  int reversed_p;
+  bool reversed_p;
 
   /** The following members contain information about the current
       grapheme cluster.  */
@@ -3002,14 +3002,14 @@ enum tool_bar_item_image
 
 /* Defined in bidi.c */
 
-extern void bidi_init_it (ptrdiff_t, ptrdiff_t, int, struct bidi_it *);
+extern void bidi_init_it (ptrdiff_t, ptrdiff_t, bool, struct bidi_it *);
 extern void bidi_move_to_visually_next (struct bidi_it *);
-extern void bidi_paragraph_init (bidi_dir_t, struct bidi_it *, int);
+extern void bidi_paragraph_init (bidi_dir_t, struct bidi_it *, bool);
 extern int  bidi_mirror_char (int);
 extern void bidi_push_it (struct bidi_it *);
 extern void bidi_pop_it (struct bidi_it *);
 extern void *bidi_shelve_cache (void);
-extern void bidi_unshelve_cache (void *, int);
+extern void bidi_unshelve_cache (void *, bool);
 
 /* Defined in xdisp.c */
 
@@ -3304,7 +3304,7 @@ extern Lisp_Object marginal_area_string (struct window *, enum window_part,
 extern void redraw_frame (struct frame *);
 extern void cancel_line (int, struct frame *);
 extern void init_desired_glyphs (struct frame *);
-extern int update_frame (struct frame *, int, int);
+extern bool update_frame (struct frame *, bool, bool);
 extern void bitch_at_user (void);
 void adjust_glyphs (struct frame *);
 void free_glyphs (struct frame *);
@@ -3320,13 +3320,13 @@ void rotate_matrix (struct glyph_matrix *, int, int, int);
 void increment_matrix_positions (struct glyph_matrix *,
                                  int, int, ptrdiff_t, ptrdiff_t);
 void blank_row (struct window *, struct glyph_row *, int);
-void enable_glyph_matrix_rows (struct glyph_matrix *, int, int, int);
+void clear_glyph_matrix_rows (struct glyph_matrix *, int, int);
 void clear_glyph_row (struct glyph_row *);
 void prepare_desired_row (struct glyph_row *);
-void set_window_update_flags (struct window *, int);
-void update_single_window (struct window *, int);
-void do_pending_window_change (int);
-void change_frame_size (struct frame *, int, int, int, int, int);
+void set_window_update_flags (struct window *, bool);
+void update_single_window (struct window *, bool);
+void do_pending_window_change (bool);
+void change_frame_size (struct frame *, int, int, bool, bool, bool);
 void init_display (void);
 void syms_of_display (void);
 extern Lisp_Object Qredisplay_dont_pause;
diff --git a/src/dispnew.c b/src/dispnew.c
index ce7c4ebcb4c..4e307880111 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -88,7 +88,7 @@ static void update_frame_line (struct frame *, int);
 static int required_matrix_height (struct window *);
 static int required_matrix_width (struct window *);
 static void adjust_frame_glyphs (struct frame *);
-static void change_frame_size_1 (struct frame *, int, int, int, int, int);
+static void change_frame_size_1 (struct frame *, int, int, bool, bool, bool);
 static void increment_row_positions (struct glyph_row *, ptrdiff_t, ptrdiff_t);
 static void fill_up_frame_row_with_spaces (struct glyph_row *, int);
 static void build_frame_matrix_from_window_tree (struct glyph_matrix *,
@@ -98,20 +98,20 @@ static void build_frame_matrix_from_leaf_window (struct glyph_matrix *,
 static void adjust_frame_message_buffer (struct frame *);
 static void adjust_decode_mode_spec_buffer (struct frame *);
 static void fill_up_glyph_row_with_spaces (struct glyph_row *);
-static void clear_window_matrices (struct window *, int);
+static void clear_window_matrices (struct window *, bool);
 static void fill_up_glyph_row_area_with_spaces (struct glyph_row *, int);
-static int scrolling_window (struct window *, int);
-static int update_window_line (struct window *, int, int *);
+static int scrolling_window (struct window *, bool);
+static bool update_window_line (struct window *, int, bool *);
 static void mirror_make_current (struct window *, int);
 #ifdef GLYPH_DEBUG
 static void check_matrix_pointers (struct glyph_matrix *,
                                    struct glyph_matrix *);
 #endif
 static void mirror_line_dance (struct window *, int, int, int *, char *);
-static int update_window_tree (struct window *, int);
-static int update_window (struct window *, int);
-static int update_frame_1 (struct frame *, int, int);
-static int scrolling (struct frame *);
+static bool update_window_tree (struct window *, bool);
+static bool update_window (struct window *, bool);
+static bool update_frame_1 (struct frame *, bool, bool);
+static bool scrolling (struct frame *);
 static void set_window_cursor_after_update (struct window *);
 static void adjust_frame_glyphs_for_window_redisplay (struct frame *);
 static void adjust_frame_glyphs_for_frame_redisplay (struct frame *);
@@ -122,14 +122,14 @@ static void adjust_frame_glyphs_for_frame_redisplay (struct frame *);
 static EMACS_TIME preemption_period;
 static EMACS_TIME preemption_next_check;
 
-/* Nonzero upon entry to redisplay means do not assume anything about
+/* True upon entry to redisplay means do not assume anything about
    current contents of actual terminal frame; clear and redraw it.  */
 
-int frame_garbaged;
+bool frame_garbaged;
 
-/* Nonzero means last display completed.  Zero means it was preempted.  */
+/* True means last display completed.  False means it was preempted.  */
 
-int display_completed;
+bool display_completed;
 
 Lisp_Object Qdisplay_table, Qredisplay_dont_pause;
 
@@ -146,13 +146,13 @@ Lisp_Object selected_frame;
 
 struct frame *last_nonminibuf_frame;
 
-/* 1 means SIGWINCH happened when not safe.  */
+/* True means SIGWINCH happened when not safe.  */
 
-static int delayed_size_change;
+static bool delayed_size_change;
 
 /* 1 means glyph initialization has been completed at startup.  */
 
-static int glyphs_initialized_initially_p;
+static bool glyphs_initialized_initially_p;
 
 /* Updated window if != 0.  Set by update_window.  */
 
@@ -178,15 +178,15 @@ static int glyph_pool_count;
 
 static struct frame *frame_matrix_frame;
 
-/* Non-zero means that fonts have been loaded since the last glyph
+/* True means that fonts have been loaded since the last glyph
    matrix adjustments.  Redisplay must stop, and glyph matrices must
-   be adjusted when this flag becomes non-zero during display.  The
+   be adjusted when this flag becomes true during display.  The
    reason fonts can be loaded so late is that fonts of fontsets are
    loaded on demand.  Another reason is that a line contains many
    characters displayed by zero width or very narrow glyphs of
    variable-width fonts.  */
 
-int fonts_changed_p;
+bool fonts_changed_p;
 
 /* Convert vpos and hpos from frame to window and vice versa.
    This may only be used for terminal frames.  */
@@ -222,16 +222,14 @@ static int history_idx;
    history.  */
 
 static uprintmax_t history_tick;
-
-static void add_frame_display_history (struct frame *, int);
 
 /* Add to the redisplay history how window W has been displayed.
    MSG is a trace containing the information how W's glyph matrix
-   has been constructed.  PAUSED_P non-zero means that the update
+   has been constructed.  PAUSED_P means that the update
    has been interrupted for pending input.  */
 
 static void
-add_window_display_history (struct window *w, const char *msg, int paused_p)
+add_window_display_history (struct window *w, const char *msg, bool paused_p)
 {
   char *buf;
 
@@ -254,11 +252,11 @@ add_window_display_history (struct window *w, const char *msg, int paused_p)
 
 
 /* Add to the redisplay history that frame F has been displayed.
-   PAUSED_P non-zero means that the update has been interrupted for
+   PAUSED_P means that the update has been interrupted for
    pending input.  */
 
 static void
-add_frame_display_history (struct frame *f, int paused_p)
+add_frame_display_history (struct frame *f, bool paused_p)
 {
   char *buf;
 
@@ -395,10 +393,10 @@ margin_glyphs_to_reserve (struct window *w, int total_glyphs, Lisp_Object margin
   return n;
 }
 
-/* Return non-zero if ROW's hash value is correct, zero if not.
+/* Return true if ROW's hash value is correct.
    Optimized away if ENABLE_CHECKING is not defined.  */
 
-static int
+static bool
 verify_row_hash (struct glyph_row *row)
 {
   return row->hash == row_hash (row);
@@ -431,9 +429,9 @@ adjust_glyph_matrix (struct window *w, struct glyph_matrix *matrix, int x, int y
 {
   int i;
   int new_rows;
-  int marginal_areas_changed_p = 0;
-  int header_line_changed_p = 0;
-  int header_line_p = 0;
+  bool marginal_areas_changed_p = 0;
+  bool header_line_changed_p = 0;
+  bool header_line_p = 0;
   int left = -1, right = -1;
   int window_width = -1, window_height = -1;
 
@@ -736,30 +734,28 @@ increment_matrix_positions (struct glyph_matrix *matrix, int start, int end,
 }
 
 
-/* Enable a range of rows in glyph matrix MATRIX.  START and END are
-   the row indices of the first and last + 1 row to enable.  If
-   ENABLED_P is non-zero, enabled_p flags in rows will be set to 1.  */
+/* Clear the enable_p flags in a range of rows in glyph matrix MATRIX.
+   START and END are the row indices of the first and last + 1 row to clear.  */
 
 void
-enable_glyph_matrix_rows (struct glyph_matrix *matrix, int start, int end, int enabled_p)
+clear_glyph_matrix_rows (struct glyph_matrix *matrix, int start, int end)
 {
   eassert (start <= end);
   eassert (start >= 0 && start < matrix->nrows);
   eassert (end >= 0 && end <= matrix->nrows);
 
   for (; start < end; ++start)
-    matrix->rows[start].enabled_p = enabled_p != 0;
+    matrix->rows[start].enabled_p = 0;
 }
 
 
 /* Clear MATRIX.
 
-   This empties all rows in MATRIX by setting the enabled_p flag for
-   all rows of the matrix to zero.  The function prepare_desired_row
-   will eventually really clear a row when it sees one with a zero
-   enabled_p flag.
+   Empty all rows in MATRIX by clearing their enabled_p flags.
+   The function prepare_desired_row will eventually really clear a row
+   when it sees one with a false enabled_p flag.
 
-   Resets update hints to defaults value.  The only update hint
+   Reset update hints to default values.  The only update hint
    currently present is the flag MATRIX->no_scrolling_p.  */
 
 void
@@ -767,7 +763,7 @@ clear_glyph_matrix (struct glyph_matrix *matrix)
 {
   if (matrix)
     {
-      enable_glyph_matrix_rows (matrix, 0, matrix->nrows, 0);
+      clear_glyph_matrix_rows (matrix, 0, matrix->nrows);
       matrix->no_scrolling_p = 0;
     }
 }
@@ -853,11 +849,11 @@ clear_desired_matrices (register struct frame *f)
 }
 
 
-/* Clear matrices in window tree rooted in W.  If DESIRED_P is
-   non-zero clear desired matrices, otherwise clear current matrices.  */
+/* Clear matrices in window tree rooted in W.  If DESIRED_P,
+   clear desired matrices, otherwise clear current matrices.  */
 
 static void
-clear_window_matrices (struct window *w, int desired_p)
+clear_window_matrices (struct window *w, bool desired_p)
 {
   while (w)
     {
@@ -1109,12 +1105,12 @@ assign_row (struct glyph_row *to, struct glyph_row *from)
 /* Test whether the glyph memory of the glyph row WINDOW_ROW, which is
    a row in a window matrix, is a slice of the glyph memory of the
    glyph row FRAME_ROW which is a row in a frame glyph matrix.  Value
-   is non-zero if the glyph memory of WINDOW_ROW is part of the glyph
+   is true if the glyph memory of WINDOW_ROW is part of the glyph
    memory of FRAME_ROW.  */
 
 #ifdef GLYPH_DEBUG
 
-static int
+static bool
 glyph_row_slice_p (struct glyph_row *window_row, struct glyph_row *frame_row)
 {
   struct glyph *window_glyph_start = window_row->glyphs[0];
@@ -1161,7 +1157,7 @@ prepare_desired_row (struct glyph_row *row)
 {
   if (!row->enabled_p)
     {
-      int rp = row->reversed_p;
+      bool rp = row->reversed_p;
 
       clear_glyph_row (row);
       row->enabled_p = 1;
@@ -1260,12 +1256,11 @@ line_draw_cost (struct glyph_matrix *matrix, int vpos)
 }
 
 
-/* Test two glyph rows A and B for equality.  Value is non-zero if A
-   and B have equal contents.  MOUSE_FACE_P non-zero means compare the
-   mouse_face_p flags of A and B, too.  */
+/* Return true if the glyph rows A and B have equal contents.
+   MOUSE_FACE_P means compare the mouse_face_p flags of A and B, too.  */
 
-static inline int
-row_equal_p (struct glyph_row *a, struct glyph_row *b, int mouse_face_p)
+static inline bool
+row_equal_p (struct glyph_row *a, struct glyph_row *b, bool mouse_face_p)
 {
   eassert (verify_row_hash (a));
   eassert (verify_row_hash (b));
@@ -1380,14 +1375,14 @@ free_glyph_pool (struct glyph_pool *pool)
    is changed from a large value to a smaller one.  But, if someone
    does it once, we can expect that he will do it again.
 
-   Value is non-zero if the pool changed in a way which makes
+   Return true if the pool changed in a way which makes
    re-adjusting window glyph matrices necessary.  */
 
-static int
+static bool
 realloc_glyph_pool (struct glyph_pool *pool, struct dim matrix_dim)
 {
   ptrdiff_t needed;
-  int changed_p;
+  bool changed_p;
 
   changed_p = (pool->glyphs == 0
                || matrix_dim.height != pool->nrows
@@ -1561,7 +1556,7 @@ check_matrix_invariants (struct window *w)
 
    X and Y are column/row within the frame glyph matrix where
    sub-matrices for the window tree rooted at WINDOW must be
-   allocated.  DIM_ONLY_P non-zero means that the caller of this
+   allocated.  DIM_ONLY_P means that the caller of this
    function is only interested in the result matrix dimension, and
    matrix adjustments should not be performed.
 
@@ -1638,7 +1633,7 @@ check_matrix_invariants (struct window *w)
 
 static struct dim
 allocate_matrices_for_frame_redisplay (Lisp_Object window, int x, int y,
-                                       int dim_only_p, int *window_change_flags)
+                                       bool dim_only_p, int *window_change_flags)
 {
   struct frame *f = XFRAME (WINDOW_FRAME (XWINDOW (window)));
   int x0 = x, y0 = y;
@@ -1646,7 +1641,7 @@ allocate_matrices_for_frame_redisplay (Lisp_Object window, int x, int y,
   struct dim total;
   struct dim dim;
   struct window *w;
-  int in_horz_combination_p;
+  bool in_horz_combination_p;
 
   /* What combination is WINDOW part of?  Compute this once since the
      result is the same for all windows in the `next' chain.  The
@@ -1704,7 +1699,7 @@ allocate_matrices_for_frame_redisplay (Lisp_Object window, int x, int y,
           /* Actually change matrices, if allowed.  Do not consider
              CHANGED_LEAF_MATRIX computed above here because the pool
              may have been changed which we don't now here.  We trust
-             that we only will be called with DIM_ONLY_P != 0 when
+             that we only will be called with DIM_ONLY_P when
              necessary.  */
           if (!dim_only_p)
             {
@@ -1919,9 +1914,9 @@ adjust_frame_glyphs (struct frame *f)
   f->glyphs_initialized_p = 1;
 }
 
-/* Return 1 if any window in the tree has nonzero window margins.  See
+/* Return true if any window in the tree has nonzero window margins.  See
    the hack at the end of adjust_frame_glyphs_for_frame_redisplay.  */
-static int
+static bool
 showing_window_margins_p (struct window *w)
 {
   while (w)
@@ -2052,7 +2047,7 @@ static void
 adjust_frame_glyphs_for_frame_redisplay (struct frame *f)
 {
   struct dim matrix_dim;
-  int pool_changed_p;
+  bool pool_changed_p;
   int window_change_flags;
   int top_window_y;
 
@@ -2468,7 +2463,7 @@ build_frame_matrix_from_window_tree (struct glyph_matrix *matrix, struct window
    desired frame matrix built.  W is a leaf window whose desired or
    current matrix is to be added to FRAME_MATRIX.  W's flag
    must_be_updated_p determines which matrix it contributes to
-   FRAME_MATRIX.  If must_be_updated_p is non-zero, W's desired matrix
+   FRAME_MATRIX.  If W->must_be_updated_p, W's desired matrix
    is added to FRAME_MATRIX, otherwise W's current matrix is added.
    Adding a desired matrix means setting up used counters and such in
    frame rows, while adding a current window matrix to FRAME_MATRIX
@@ -2519,7 +2514,7 @@ build_frame_matrix_from_leaf_window (struct glyph_matrix *frame_matrix, struct w
     {
       struct glyph_row *frame_row = frame_matrix->rows + frame_y;
       struct glyph_row *window_row = window_matrix->rows + window_y;
-      int current_row_p = window_matrix == w->current_matrix;
+      bool current_row_p = window_matrix == w->current_matrix;
 
       /* Fill up the frame row with spaces up to the left margin of the
          window row.  */
@@ -2692,7 +2687,7 @@ make_current (struct glyph_matrix *desired_matrix, struct glyph_matrix *current_
 {
   struct glyph_row *current_row = MATRIX_ROW (current_matrix, row);
   struct glyph_row *desired_row = MATRIX_ROW (desired_matrix, row);
-  int mouse_face_p = current_row->mouse_face_p;
+  bool mouse_face_p = current_row->mouse_face_p;
 
   /* Do current_row = desired_row.  This exchanges glyph pointers
      between both rows, and does a structure assignment otherwise.  */
@@ -2789,7 +2784,7 @@ mirrored_line_dance (struct glyph_matrix *matrix, int unchanged_at_top, int nlin
   /* Assign new rows, maybe clear lines.  */
   for (i = 0; i < nlines; ++i)
     {
-      int enabled_before_p = new_rows[i].enabled_p;
+      bool enabled_before_p = new_rows[i].enabled_p;
 
       eassert (i + unchanged_at_top < matrix->nrows);
       eassert (unchanged_at_top + copy_from[i] < matrix->nrows);
@@ -2897,7 +2892,8 @@ mirror_line_dance (struct window *w, int unchanged_at_top, int nlines, int *copy
           /* W is a leaf window, and we are working on its current
              matrix m.  */
           struct glyph_matrix *m = w->current_matrix;
-          int i, sync_p = 0;
+          int i;
+          bool sync_p = 0;
           struct glyph_row *old_rows;
 
           /* Make a copy of the original rows of matrix m.  */
@@ -2919,22 +2915,19 @@ mirror_line_dance (struct window *w, int unchanged_at_top, int nlines, int *copy
               int window_from = frame_from - m->matrix_y;
 
               /* Is assigned line inside window?  */
-              int from_inside_window_p
+              bool from_inside_window_p
                 = window_from >= 0 && window_from < m->matrix_h;
 
               /* Is assigned to line inside window?  */
-              int to_inside_window_p
+              bool to_inside_window_p
                 = window_to >= 0 && window_to < m->matrix_h;
 
               if (from_inside_window_p && to_inside_window_p)
                 {
-                  /* Enabled setting before assignment.  */
-                  int enabled_before_p;
-
                   /* Do the assignment.  The enabled_p flag is saved
                      over the assignment because the old redisplay did
                      that.  */
-                  enabled_before_p = m->rows[window_to].enabled_p;
+                  bool enabled_before_p = m->rows[window_to].enabled_p;
                   m->rows[window_to] = old_rows[window_from];
                   m->rows[window_to].enabled_p = enabled_before_p;
 
@@ -3155,17 +3148,16 @@ DEFUN ("redraw-display", Fredraw_display, Sredraw_display, 0, 0, "",
 
 /* Update frame F based on the data in desired matrices.
 
-   If FORCE_P is non-zero, don't let redisplay be stopped by detecting
-   pending input.  If INHIBIT_HAIRY_ID_P is non-zero, don't try
-   scrolling.
+   If FORCE_P, don't let redisplay be stopped by detecting pending input.
+   If INHIBIT_HAIRY_ID_P, don't try scrolling.
 
-   Value is non-zero if redisplay was stopped due to pending input.  */
+   Value is true if redisplay was stopped due to pending input.  */
 
-int
-update_frame (struct frame *f, int force_p, int inhibit_hairy_id_p)
+bool
+update_frame (struct frame *f, bool force_p, bool inhibit_hairy_id_p)
 {
-  /* 1 means display has been paused because of pending input.  */
-  int paused_p;
+  /* True means display has been paused because of pending input.  */
+  bool paused_p;
   struct window *root_window = XWINDOW (f->root_window);
 
   if (redisplay_dont_pause)
@@ -3283,13 +3275,13 @@ update_frame (struct frame *f, int force_p, int inhibit_hairy_id_p)
                          Window-based updates
  ************************************************************************/
 
-/* Perform updates in window tree rooted at W.  FORCE_P non-zero means
-   don't stop updating when input is pending.  */
+/* Perform updates in window tree rooted at W.
+   If FORCE_P, don't stop updating if input is pending.  */
 
-static int
-update_window_tree (struct window *w, int force_p)
+static bool
+update_window_tree (struct window *w, bool force_p)
 {
-  int paused_p = 0;
+  bool paused_p = 0;
 
   while (w && !paused_p)
     {
@@ -3307,11 +3299,11 @@ update_window_tree (struct window *w, int force_p)
 }
 
 
-/* Update window W if its flag must_be_updated_p is non-zero.  If
-   FORCE_P is non-zero, don't stop updating if input is pending.  */
+/* Update window W if its flag must_be_updated_p is set.
+   If FORCE_P, don't stop updating if input is pending.  */
 
 void
-update_single_window (struct window *w, int force_p)
+update_single_window (struct window *w, bool force_p)
 {
   if (w->must_be_updated_p)
     {
@@ -3460,7 +3452,7 @@ redraw_overlapping_rows (struct window *w, int yb)
 static void
 check_current_matrix_flags (struct window *w)
 {
-  int last_seen_p = 0;
+  bool last_seen_p = 0;
   int i, yb = window_text_bottom_y (w);
 
   for (i = 0; i < w->current_matrix->nrows - 1; ++i)
@@ -3476,14 +3468,14 @@ check_current_matrix_flags (struct window *w)
 #endif /* GLYPH_DEBUG */
 
 
-/* Update display of window W.  FORCE_P non-zero means that we should
-   not stop when detecting pending input.  */
+/* Update display of window W.
+   If FORCE_P, don't stop updating when input is pending.  */
 
-static int
-update_window (struct window *w, int force_p)
+static bool
+update_window (struct window *w, bool force_p)
 {
   struct glyph_matrix *desired_matrix = w->desired_matrix;
-  int paused_p;
+  bool paused_p;
 #if !PERIODIC_PREEMPTION_CHECKING
   int preempt_count = baud_rate / 2400 + 1;
 #endif
@@ -3506,7 +3498,8 @@ update_window (struct window *w, int force_p)
       struct glyph_row *row, *end;
       struct glyph_row *mode_line_row;
       struct glyph_row *header_line_row;
-      int yb, changed_p = 0, mouse_face_overwritten_p = 0;
+      int yb;
+      bool changed_p = 0, mouse_face_overwritten_p = 0;
 #if ! PERIODIC_PREEMPTION_CHECKING
       int n_updated = 0;
 #endif
@@ -3693,15 +3686,15 @@ update_marginal_area (struct window *w, int area, int vpos)
 
 
 /* Update the display of the text area of row VPOS in window W.
-   Value is non-zero if display has changed.  */
+   Value is true if display has changed.  */
 
-static int
+static bool
 update_text_area (struct window *w, int vpos)
 {
   struct glyph_row *current_row = MATRIX_ROW (w->current_matrix, vpos);
   struct glyph_row *desired_row = MATRIX_ROW (w->desired_matrix, vpos);
   struct redisplay_interface *rif = FRAME_RIF (XFRAME (WINDOW_FRAME (w)));
-  int changed_p = 0;
+  bool changed_p = 0;
 
   /* Let functions in xterm.c know what area subsequent X positions
      will be relative to.  */
@@ -3751,9 +3744,9 @@ update_text_area (struct window *w, int vpos)
       int stop, i, x;
       struct glyph *current_glyph = current_row->glyphs[TEXT_AREA];
       struct glyph *desired_glyph = desired_row->glyphs[TEXT_AREA];
-      int overlapping_glyphs_p = current_row->contains_overlapping_glyphs_p;
+      bool overlapping_glyphs_p = current_row->contains_overlapping_glyphs_p;
       int desired_stop_pos = desired_row->used[TEXT_AREA];
-      int abort_skipping = 0;
+      bool abort_skipping = 0;
 
       /* If the desired row extends its face to the text area end, and
          unless the current row also does so at the same position,
@@ -3773,7 +3766,7 @@ update_text_area (struct window *w, int vpos)
          in common.  */
       while (i < stop)
         {
-          int can_skip_p = !abort_skipping;
+          bool can_skip_p = !abort_skipping;
 
           /* Skip over glyphs that both rows have in common.  These
              don't have to be written.  We can't skip if the last
@@ -3847,7 +3840,7 @@ update_text_area (struct window *w, int vpos)
               int start_x = x, start_hpos = i;
               struct glyph *start = desired_glyph;
               int current_x = x;
-              int skip_first_p = !can_skip_p;
+              bool skip_first_p = !can_skip_p;
 
               /* Find the next glyph that's equal again.  */
               while (i < stop
@@ -3938,16 +3931,15 @@ update_text_area (struct window *w, int vpos)
 }
 
 
-/* Update row VPOS in window W.  Value is non-zero if display has been
-   changed.  */
+/* Update row VPOS in window W.  Value is true if display has been changed.  */
 
-static int
-update_window_line (struct window *w, int vpos, int *mouse_face_overwritten_p)
+static bool
+update_window_line (struct window *w, int vpos, bool *mouse_face_overwritten_p)
 {
   struct glyph_row *current_row = MATRIX_ROW (w->current_matrix, vpos);
   struct glyph_row *desired_row = MATRIX_ROW (w->desired_matrix, vpos);
   struct redisplay_interface *rif = FRAME_RIF (XFRAME (WINDOW_FRAME (w)));
-  int changed_p = 0;
+  bool changed_p = 0;
 
   /* Set the row being updated.  This is important to let xterm.c
      know what line height values are in effect.  */
@@ -4095,7 +4087,7 @@ set_window_cursor_after_update (struct window *w)
    tree rooted at W.  */
 
 void
-set_window_update_flags (struct window *w, int on_p)
+set_window_update_flags (struct window *w, bool on_p)
 {
   while (w)
     {
@@ -4198,7 +4190,7 @@ add_row_entry (struct glyph_row *row)
 
 
 /* Try to reuse part of the current display of W by scrolling lines.
-   HEADER_LINE_P non-zero means W has a header line.
+   HEADER_LINE_P means W has a header line.
 
    The algorithm is taken from Communications of the ACM, Apr78 "A
    Technique for Isolating Differences Between Files."  It should take
@@ -4224,7 +4216,7 @@ add_row_entry (struct glyph_row *row)
    1    if we did scroll.  */
 
 static int
-scrolling_window (struct window *w, int header_line_p)
+scrolling_window (struct window *w, bool header_line_p)
 {
   struct glyph_matrix *desired_matrix = w->desired_matrix;
   struct glyph_matrix *current_matrix = w->current_matrix;
@@ -4237,7 +4229,7 @@ scrolling_window (struct window *w, int header_line_p)
   struct redisplay_interface *rif = FRAME_RIF (XFRAME (WINDOW_FRAME (w)));
 
   /* Skip over rows equal at the start.  */
-  for (i = header_line_p ? 1 : 0; i < current_matrix->nrows - 1; ++i)
+  for (i = header_line_p; i < current_matrix->nrows - 1; ++i)
     {
       struct glyph_row *d = MATRIX_ROW (desired_matrix, i);
       struct glyph_row *c = MATRIX_ROW (current_matrix, i);
@@ -4496,7 +4488,7 @@ scrolling_window (struct window *w, int header_line_p)
         for (j = nruns - 1; j > i; --j)
           {
             struct run *p = runs[j];
-            int truncated_p = 0;
+            bool truncated_p = 0;
 
             if (p->nrows > 0
                 && p->desired_y < r->desired_y + r->height
@@ -4559,7 +4551,7 @@ scrolling_window (struct window *w, int header_line_p)
         for (j = 0; j < r->nrows; ++j)
           {
             struct glyph_row *from, *to;
-            int to_overlapped_p;
+            bool to_overlapped_p;
 
             to = MATRIX_ROW (current_matrix, r->desired_vpos + j);
             from = MATRIX_ROW (desired_matrix, r->desired_vpos + j);
@@ -4594,20 +4586,19 @@ scrolling_window (struct window *w, int header_line_p)
 
 /* Update the desired frame matrix of frame F.
 
-   FORCE_P non-zero means that the update should not be stopped by
-   pending input.  INHIBIT_HAIRY_ID_P non-zero means that scrolling
-   should not be tried.
+   FORCE_P means that the update should not be stopped by pending input.
+   INHIBIT_HAIRY_ID_P means that scrolling should not be tried.
 
-   Value is non-zero if update was stopped due to pending input.  */
+   Value is true if update was stopped due to pending input.  */
 
-static int
-update_frame_1 (struct frame *f, int force_p, int inhibit_id_p)
+static bool
+update_frame_1 (struct frame *f, bool force_p, bool inhibit_id_p)
 {
   /* Frame matrices to work on.  */
   struct glyph_matrix *current_matrix = f->current_matrix;
   struct glyph_matrix *desired_matrix = f->desired_matrix;
   int i;
-  int pause_p;
+  bool pause_p;
   int preempt_count = baud_rate / 2400 + 1;
 
   eassert (current_matrix && desired_matrix);
@@ -4699,7 +4690,7 @@ update_frame_1 (struct frame *f, int force_p, int inhibit_id_p)
         }
     }
 
-  pause_p = (i < FRAME_LINES (f) - 1) ? i : 0;
+  pause_p = 0 < i && i < FRAME_LINES (f) - 1;
 
   /* Now just clean up termcap drivers and set cursor, etc.  */
   if (!pause_p)
@@ -4809,7 +4800,7 @@ update_frame_1 (struct frame *f, int force_p, int inhibit_id_p)
 
 /* Do line insertions/deletions on frame F for frame-based redisplay.  */
 
-static int
+static bool
 scrolling (struct frame *frame)
 {
   int unchanged_at_top, unchanged_at_bottom;
@@ -4952,10 +4943,10 @@ update_frame_line (struct frame *f, int vpos)
   struct glyph_matrix *desired_matrix = f->desired_matrix;
   struct glyph_row *current_row = MATRIX_ROW (current_matrix, vpos);
   struct glyph_row *desired_row = MATRIX_ROW (desired_matrix, vpos);
-  int must_write_whole_line_p;
-  int write_spaces_p = FRAME_MUST_WRITE_SPACES (f);
-  int colored_spaces_p = (FACE_FROM_ID (f, DEFAULT_FACE_ID)->background
-                          != FACE_TTY_DEFAULT_BG_COLOR);
+  bool must_write_whole_line_p;
+  bool write_spaces_p = FRAME_MUST_WRITE_SPACES (f);
+  bool colored_spaces_p = (FACE_FROM_ID (f, DEFAULT_FACE_ID)->background
+                           != FACE_TTY_DEFAULT_BG_COLOR);
 
   if (colored_spaces_p)
     write_spaces_p = 1;
@@ -5289,7 +5280,7 @@ buffer_posn_from_coords (struct window *w, int *x, int *y, struct display_pos *p
   /* start_display takes into account the header-line row, but IT's
      vpos still counts from the glyph row that includes the window's
      start position.  Adjust for a possible header-line row.  */
-  it.vpos += WINDOW_WANTS_HEADER_LINE_P (w) ? 1 : 0;
+  it.vpos += WINDOW_WANTS_HEADER_LINE_P (w);
 
   x0 = *x;
 
@@ -5613,12 +5604,12 @@ window_change_signal (int signalnum) /* If we don't have an argument, */
 #endif /* SIGWINCH */
 
 
-/* Do any change in frame size that was requested by a signal.  SAFE
-   non-zero means this function is called from a place where it is
-   safe to change frame sizes  while a redisplay is in progress.  */
+/* Do any change in frame size that was requested by a signal.
+   SAFE means this function is called from a place where it is
+   safe to change frame sizes while a redisplay is in progress.  */
 
 void
-do_pending_window_change (int safe)
+do_pending_window_change (bool safe)
 {
   /* If window_change_signal should have run before, run it now.  */
   if (redisplaying_p && !safe)
@@ -5645,16 +5636,17 @@ do_pending_window_change (int safe)
 /* Change the frame height and/or width.  Values may be given as zero to
    indicate no change is to take place.
 
-   If DELAY is non-zero, then assume we're being called from a signal
-   handler, and queue the change for later - perhaps the next
-   redisplay.  Since this tries to resize windows, we can't call it
+   If DELAY, assume we're being called from a signal handler, and
+   queue the change for later - perhaps the next redisplay.
+   Since this tries to resize windows, we can't call it
    from a signal handler.
 
-   SAFE non-zero means this function is called from a place where it's
+   SAFE means this function is called from a place where it's
    safe to change frame sizes while a redisplay is in progress.  */
 
 void
-change_frame_size (register struct frame *f, int newheight, int newwidth, int pretend, int delay, int safe)
+change_frame_size (struct frame *f, int newheight, int newwidth,
+                   bool pretend, bool delay, bool safe)
 {
   Lisp_Object tail, frame;
 
@@ -5673,7 +5665,8 @@ change_frame_size (register struct frame *f, int newheight, int newwidth, int pr
 }
 
 static void
-change_frame_size_1 (register struct frame *f, int newheight, int newwidth, int pretend, int delay, int safe)
+change_frame_size_1 (struct frame *f, int newheight, int newwidth,
+                     bool pretend, bool delay, bool safe)
 {
   int new_frame_total_cols;
   ptrdiff_t count = SPECPDL_INDEX ();
@@ -5769,7 +5762,7 @@ change_frame_size_1 (register struct frame *f, int newheight, int newwidth, int
 
   UNBLOCK_INPUT;
 
-  record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+  record_unwind_current_buffer ();
 
   run_window_configuration_change_hook (f);
 
@@ -5929,13 +5922,13 @@ additional wait period, in milliseconds; this is for backwards compatibility.
 
    TIMEOUT is number of seconds to wait (float or integer),
    or t to wait forever.
-   READING is 1 if reading input.
+   READING is true if reading input.
    If DO_DISPLAY is >0 display process output while waiting.
    If DO_DISPLAY is >1 perform an initial redisplay before waiting.
 */
 
 Lisp_Object
-sit_for (Lisp_Object timeout, int reading, int do_display)
+sit_for (Lisp_Object timeout, bool reading, int do_display)
 {
   intmax_t sec;
   int nsec;
diff --git a/src/editfns.c b/src/editfns.c
index 0bd632d14b7..7b451e4e443 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -946,13 +946,10 @@ BODY is executed just like `progn'.
 usage: (save-current-buffer &rest BODY)  */)
   (Lisp_Object args)
 {
-  Lisp_Object val;
   ptrdiff_t count = SPECPDL_INDEX ();
 
-  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
-
-  val = Fprogn (args);
-  return unbind_to (count, val);
+  record_unwind_current_buffer ();
+  return unbind_to (count, Fprogn (args));
 }
 
 DEFUN ("buffer-size", Fbufsize, Sbufsize, 0, 1, 0,
diff --git a/src/emacs.c b/src/emacs.c
index 9e7efcabbf7..7ff5c43dbea 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -279,11 +279,6 @@ static int fatal_error_code;
 /* Nonzero if handling a fatal error already.  */
 int fatal_error_in_progress;
 
-/* If non-null, call this function from fatal_error_signal before
-   committing suicide.  */
-
-static void (*fatal_error_signal_hook) (void);
-
 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 /* When compiled with GTK and running under Gnome,
    multiple threads may be created.  Keep track of our main
@@ -331,9 +326,6 @@ fatal_error_signal (int sig)
   sigunblock (sigmask (fatal_error_code));
 #endif
 
-  if (fatal_error_signal_hook)
-    fatal_error_signal_hook ();
-
   kill (getpid (), fatal_error_code);
 }
 
diff --git a/src/eval.c b/src/eval.c
index c41e3f54d4d..df44c87dc25 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -2722,33 +2722,9 @@ DEFUN ("functionp", Ffunctionp, Sfunctionp, 1, 1, 0,
        doc: /* Non-nil if OBJECT is a function.  */)
      (Lisp_Object object)
 {
-  if (SYMBOLP (object) && !NILP (Ffboundp (object)))
-    {
-      object = Findirect_function (object, Qt);
-
-      if (CONSP (object) && EQ (XCAR (object), Qautoload))
-        {
-          /* Autoloaded symbols are functions, except if they load
-             macros or keymaps.  */
-          int i;
-          for (i = 0; i < 4 && CONSP (object); i++)
-            object = XCDR (object);
-
-          return (CONSP (object) && !NILP (XCAR (object))) ? Qnil : Qt;
-        }
-    }
-
-  if (SUBRP (object))
-    return (XSUBR (object)->max_args != UNEVALLED) ? Qt : Qnil;
-  else if (COMPILEDP (object))
+  if (FUNCTIONP (object))
     return Qt;
-  else if (CONSP (object))
-    {
-      Lisp_Object car = XCAR (object);
-      return (EQ (car, Qlambda) || EQ (car, Qclosure)) ? Qt : Qnil;
-    }
-  else
-    return Qnil;
+  return Qnil;
 }
 
 DEFUN ("funcall", Ffuncall, Sfuncall, 1, MANY, 0,
diff --git a/src/fileio.c b/src/fileio.c
index 6deca0bf1e1..7466914af1c 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -3142,8 +3142,7 @@ decide_coding_unwind (Lisp_Object unwind_data)
   undo_list = XCAR (unwind_data);
   buffer = XCDR (unwind_data);
 
-  if (current_buffer != XBUFFER (buffer))
-    set_buffer_internal (XBUFFER (buffer));
+  set_buffer_internal (XBUFFER (buffer));
   adjust_markers_for_delete (BEG, BEG_BYTE, Z, Z_BYTE);
   adjust_overlays_for_delete (BEG, Z - BEG);
   set_buffer_intervals (current_buffer, NULL);
@@ -3481,7 +3480,7 @@ variable `last-coding-system-used' to the coding system actually used.  */)
                   Lisp_Object workbuf;
                   struct buffer *buf;
 
-                  record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+                  record_unwind_current_buffer ();
 
                   workbuf = Fget_buffer_create (build_string (" *code-converting-work*"));
                   buf = XBUFFER (workbuf);
@@ -3760,7 +3759,8 @@ variable `last-coding-system-used' to the coding system actually used.  */)
       ptrdiff_t temp;
       ptrdiff_t this = 0;
       ptrdiff_t this_count = SPECPDL_INDEX ();
-      int multibyte = ! NILP (BVAR (current_buffer, enable_multibyte_characters));
+      bool multibyte
+        = ! NILP (BVAR (current_buffer, enable_multibyte_characters));
       Lisp_Object conversion_buffer;
       struct gcpro gcpro1;
 
diff --git a/src/fns.c b/src/fns.c
index 3225fefc5e3..f6acdcada3f 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -1100,7 +1100,7 @@ an error is signaled.  */)
     {
       ptrdiff_t chars = SCHARS (string);
       unsigned char *str = xmalloc (chars);
-      ptrdiff_t converted = str_to_unibyte (SDATA (string), str, chars, 0);
+      ptrdiff_t converted = str_to_unibyte (SDATA (string), str, chars);
 
       if (converted < chars)
         error ("Can't convert the %"pD"dth character to unibyte", converted);
@@ -4656,13 +4656,12 @@ secure_hash (Lisp_Object algorithm, Lisp_Object object, Lisp_Object start, Lisp_
     {
       struct buffer *prev = current_buffer;
 
-      record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+      record_unwind_current_buffer ();
 
       CHECK_BUFFER (object);
 
       bp = XBUFFER (object);
-      if (bp != current_buffer)
-        set_buffer_internal (bp);
+      set_buffer_internal (bp);
 
       if (NILP (start))
         b = BEGV;
@@ -4749,8 +4748,7 @@ secure_hash (Lisp_Object algorithm, Lisp_Object object, Lisp_Object start, Lisp_
         }
 
       object = make_buffer_string (b, e, 0);
-      if (prev != current_buffer)
-        set_buffer_internal (prev);
+      set_buffer_internal (prev);
       /* Discard the unwind protect for recovering the current
          buffer.  */
       specpdl_ptr--;
diff --git a/src/frame.c b/src/frame.c
index a00f44a1e5a..4785840a95f 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -4247,7 +4247,6 @@ syms_of_frame (void)
   DEFSYM (Qx, "x");
   DEFSYM (Qw32, "w32");
   DEFSYM (Qpc, "pc");
-  DEFSYM (Qmac, "mac");
   DEFSYM (Qns, "ns");
   DEFSYM (Qvisible, "visible");
   DEFSYM (Qbuffer_predicate, "buffer-predicate");
diff --git a/src/frame.h b/src/frame.h
index 92fbda42c70..9421aa45414 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -34,7 +34,7 @@ INLINE_HEADER_BEGIN
 /* Miscellanea.  */
 
 /* Nonzero means there is at least one garbaged frame. */
-extern int frame_garbaged;
+extern bool frame_garbaged;
 
 
 /* The structure representing a frame.  */
@@ -621,11 +621,21 @@ typedef struct frame *FRAME_PTR;
 #define FRAME_INITIAL_P(f) ((f)->output_method == output_initial)
 #define FRAME_TERMCAP_P(f) ((f)->output_method == output_termcap)
 #define FRAME_X_P(f) ((f)->output_method == output_x_window)
+#ifndef WINDOWSNT
+#define FRAME_W32_P(f) (0)
+#else
 #define FRAME_W32_P(f) ((f)->output_method == output_w32)
+#endif
+#ifndef MSDOS
+#define FRAME_MSDOS_P(f) (0)
+#else
 #define FRAME_MSDOS_P(f) ((f)->output_method == output_msdos_raw)
-#define FRAME_MAC_P(f) ((f)->output_method == output_mac)
+#endif
+#ifndef HAVE_NS
+#define FRAME_NS_P(f) (0)
+#else
 #define FRAME_NS_P(f) ((f)->output_method == output_ns)
-
+#endif
 /* FRAME_WINDOW_P tests whether the frame is a window, and is
    defined to be the predicate for the window system being used.  */
 
diff --git a/src/insdel.c b/src/insdel.c
index 1dceb67bffa..8cb98566085 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -1779,8 +1779,7 @@ modify_region (struct buffer *buffer, ptrdiff_t start, ptrdiff_t end,
 {
   struct buffer *old_buffer = current_buffer;
 
-  if (buffer != old_buffer)
-    set_buffer_internal (buffer);
+  set_buffer_internal (buffer);
 
   prepare_to_modify_buffer (start, end, NULL);
 
@@ -1794,8 +1793,7 @@ modify_region (struct buffer *buffer, ptrdiff_t start, ptrdiff_t end,
 
   bset_point_before_scroll (buffer, Qnil);
 
-  if (buffer != old_buffer)
-    set_buffer_internal (old_buffer);
+  set_buffer_internal (old_buffer);
 }
 
 /* Check that it is okay to modify the buffer between START and END,
@@ -2119,7 +2117,7 @@ DEFUN ("combine-after-change-execute", Fcombine_after_change_execute,
       return Qnil;
     }
 
-  record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+  record_unwind_current_buffer ();
 
   Fset_buffer (combine_after_change_buffer);
 
diff --git a/src/keyboard.c b/src/keyboard.c
index 3d4061accfc..d9b88a8a911 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -1434,8 +1434,7 @@ command_loop_1 (void)
         Fkill_emacs (Qnil);
 
       /* Make sure the current window's buffer is selected.  */
-      if (XBUFFER (XWINDOW (selected_window)->buffer) != current_buffer)
-        set_buffer_internal (XBUFFER (XWINDOW (selected_window)->buffer));
+      set_buffer_internal (XBUFFER (XWINDOW (selected_window)->buffer));
 
       /* Display any malloc warning that just came out.  Use while because
          displaying one warning can cause another.  */
@@ -1513,8 +1512,7 @@ command_loop_1 (void)
       /* A filter may have run while we were reading the input.  */
       if (! FRAME_LIVE_P (XFRAME (selected_frame)))
         Fkill_emacs (Qnil);
-      if (XBUFFER (XWINDOW (selected_window)->buffer) != current_buffer)
-        set_buffer_internal (XBUFFER (XWINDOW (selected_window)->buffer));
+      set_buffer_internal (XBUFFER (XWINDOW (selected_window)->buffer));
 
       ++num_input_keys;
 
@@ -9574,7 +9572,7 @@ read_key_sequence (Lisp_Object *keybuf, int bufsize, Lisp_Object prompt,
                          because we may get input from a subprocess which
                          wants to change the selected window and stuff (say,
                          emacsclient).  */
-                      record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+                      record_unwind_current_buffer ();
 
                       if (! FRAME_LIVE_P (XFRAME (selected_frame)))
                         Fkill_emacs (Qnil);
@@ -11251,7 +11249,7 @@ The `posn-' functions access elements of such lists.  */)
 
   if (WINDOWP (frame_or_window))
     {
-      struct window *w = decode_valid_window (frame_or_window);
+      struct window *w = decode_live_window (frame_or_window);
 
       XSETINT (x, (XINT (x)
                    + WINDOW_LEFT_EDGE_X (w)
diff --git a/src/keymap.c b/src/keymap.c
index 21f7dcb5d37..4031091501c 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -1570,9 +1570,7 @@ like in the respective argument of `key-binding'. */)
              would not be a problem here, but it is easier to keep
              things the same.
           */
-
-          record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
-
+          record_unwind_current_buffer ();
           set_buffer_internal (XBUFFER (XWINDOW (window)->buffer));
         }
     }
diff --git a/src/lisp.h b/src/lisp.h
index d9a7c9d0bdc..49a2832d686 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -606,10 +606,8 @@ clip_to_bounds (ptrdiff_t lower, EMACS_INT num, ptrdiff_t upper)
 
 #define AREF(ARRAY, IDX)        XVECTOR ((ARRAY))->contents[IDX]
 #define ASIZE(ARRAY)            XVECTOR ((ARRAY))->header.size
-/* The IDX==IDX tries to detect when the macro argument is side-effecting.  */
 #define ASET(ARRAY, IDX, VAL)   \
-  (eassert ((IDX) == (IDX)),                            \
-   eassert ((IDX) >= 0 && (IDX) < ASIZE (ARRAY)),       \
+  (eassert (0 <= (IDX) && (IDX) < ASIZE (ARRAY)),       \
    XVECTOR (ARRAY)->contents[IDX] = (VAL))
 
 /* Convenience macros for dealing with Lisp strings.  */
@@ -1906,11 +1904,7 @@ typedef struct {
                          Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object)
 
 /* Non-zero if OBJ is a Lisp function.  */
-#define FUNCTIONP(OBJ)                                  \
-     ((CONSP (OBJ) && EQ (XCAR (OBJ), Qlambda))         \
-      || (SYMBOLP (OBJ) && !NILP (Ffboundp (OBJ)))      \
-      || COMPILEDP (OBJ)                                \
-      || SUBRP (OBJ))
+#define FUNCTIONP(OBJ) functionp(OBJ)
 
 /* defsubr (Sname);
    is how we define the symbol for function `name' at start-up time.  */
@@ -2579,8 +2573,7 @@ extern Lisp_Object Qoverflow_error, Qunderflow_error;
 extern Lisp_Object Qfloatp;
 extern Lisp_Object Qnumberp, Qnumber_or_marker_p;
 
-extern Lisp_Object Qinteger, Qinterval, Qsymbol, Qstring;
-extern Lisp_Object Qmisc, Qvector, Qfloat, Qcons, Qbuffer;
+extern Lisp_Object Qbuffer, Qinteger, Qsymbol;
 
 extern Lisp_Object Qfont_spec, Qfont_entity, Qfont_object;
 
@@ -2627,7 +2620,7 @@ extern _Noreturn void args_out_of_range_3 (Lisp_Object, Lisp_Object,
                                            Lisp_Object);
 extern _Noreturn Lisp_Object wrong_type_argument (Lisp_Object, Lisp_Object);
 extern Lisp_Object do_symval_forwarding (union Lisp_Fwd *);
-extern void set_internal (Lisp_Object, Lisp_Object, Lisp_Object, int);
+extern void set_internal (Lisp_Object, Lisp_Object, Lisp_Object, bool);
 extern void syms_of_data (void);
 extern void init_data (void);
 extern void swap_in_global_binding (struct Lisp_Symbol *);
@@ -2639,7 +2632,7 @@ extern void keys_of_cmds (void);
 /* Defined in coding.c */
 extern Lisp_Object Qcharset;
 extern Lisp_Object detect_coding_system (const unsigned char *, ptrdiff_t,
-                                         ptrdiff_t, int, int, Lisp_Object);
+                                         ptrdiff_t, bool, bool, Lisp_Object);
 extern void init_coding (void);
 extern void init_coding_once (void);
 extern void syms_of_coding (void);
@@ -2773,7 +2766,7 @@ _Noreturn void __executable_start (void);
 #endif
 extern Lisp_Object selected_frame;
 extern Lisp_Object Vwindow_system;
-extern Lisp_Object sit_for (Lisp_Object, int, int);
+extern Lisp_Object sit_for (Lisp_Object, bool, int);
 extern void init_display (void);
 extern void syms_of_display (void);
 
@@ -3110,14 +3103,14 @@ extern void syms_of_editfns (void);
 extern void set_time_zone_rule (const char *);
 
 /* Defined in buffer.c.  */
-extern int mouse_face_overlay_overlaps (Lisp_Object);
+extern bool mouse_face_overlay_overlaps (Lisp_Object);
 extern _Noreturn void nsberror (Lisp_Object);
 extern void adjust_overlays_for_insert (ptrdiff_t, ptrdiff_t);
 extern void adjust_overlays_for_delete (ptrdiff_t, ptrdiff_t);
 extern void fix_start_end_in_overlays (ptrdiff_t, ptrdiff_t);
-extern void report_overlay_modification (Lisp_Object, Lisp_Object, int,
+extern void report_overlay_modification (Lisp_Object, Lisp_Object, bool,
                                          Lisp_Object, Lisp_Object, Lisp_Object);
-extern int overlay_touches_p (ptrdiff_t);
+extern bool overlay_touches_p (ptrdiff_t);
 extern Lisp_Object Vbuffer_alist;
 extern Lisp_Object set_buffer_if_live (Lisp_Object);
 extern Lisp_Object other_buffer_safely (Lisp_Object);
@@ -3330,7 +3323,7 @@ extern void setup_process_coding_systems (Lisp_Object);
 #ifndef DOS_NT
  _Noreturn
 #endif
-extern int child_setup (int, int, int, char **, int, Lisp_Object);
+extern int child_setup (int, int, int, char **, bool, Lisp_Object);
 extern void init_callproc_1 (void);
 extern void init_callproc (void);
 extern void set_initial_environment (void);
@@ -3441,7 +3434,7 @@ extern void syms_of_ccl (void);
 extern void syms_of_dired (void);
 extern Lisp_Object directory_files_internal (Lisp_Object, Lisp_Object,
                                              Lisp_Object, Lisp_Object,
-                                             int, Lisp_Object);
+                                             bool, Lisp_Object);
 
 /* Defined in term.c */
 extern int *char_ins_del_vector;
@@ -3586,7 +3579,7 @@ extern Lisp_Object safe_alloca_unwind (Lisp_Object);
 extern void *record_xmalloc (size_t);
 
 #define USE_SAFE_ALLOCA                 \
-  ptrdiff_t sa_count = SPECPDL_INDEX (); int sa_must_free = 0
+  ptrdiff_t sa_count = SPECPDL_INDEX (); bool sa_must_free = 0
 
 /* SAFE_ALLOCA allocates a simple buffer.  */
 
@@ -3656,6 +3649,38 @@ maybe_gc (void)
     Fgarbage_collect ();
 }
 
+LISP_INLINE int
+functionp (Lisp_Object object)
+{
+  if (SYMBOLP (object) && !NILP (Ffboundp (object)))
+    {
+      object = Findirect_function (object, Qt);
+
+      if (CONSP (object) && EQ (XCAR (object), Qautoload))
+        {
+          /* Autoloaded symbols are functions, except if they load
+             macros or keymaps.  */
+          int i;
+          for (i = 0; i < 4 && CONSP (object); i++)
+            object = XCDR (object);
+
+          return ! (CONSP (object) && !NILP (XCAR (object)));
+        }
+    }
+
+  if (SUBRP (object))
+    return XSUBR (object)->max_args != UNEVALLED;
+  else if (COMPILEDP (object))
+    return 1;
+  else if (CONSP (object))
+    {
+      Lisp_Object car = XCAR (object);
+      return EQ (car, Qlambda) || EQ (car, Qclosure);
+    }
+  else
+    return 0;
+}
+
 INLINE_HEADER_END
 
 #endif /* EMACS_LISP_H */
diff --git a/src/makefile.w32-in b/src/makefile.w32-in
index bdb292099bc..e5959e0b1a5 100644
--- a/src/makefile.w32-in
+++ b/src/makefile.w32-in
@@ -480,6 +480,7 @@ $(BLD)/alloc.$(O) : \
         $(SRC)/syssignal.h \
         $(SRC)/w32.h \
         $(NT_INC)/unistd.h \
+        $(GNU_LIB)/execinfo.h \
         $(GNU_LIB)/verify.h \
         $(BLOCKINPUT_H) \
         $(BUFFER_H) \
diff --git a/src/minibuf.c b/src/minibuf.c
index 2154d1654df..41cc48017eb 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -817,7 +817,7 @@ get_minibuffer (EMACS_INT depth)
          while the buffer doesn't know about them any more.  */
       delete_all_overlays (XBUFFER (buf));
       reset_buffer (XBUFFER (buf));
-      record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+      record_unwind_current_buffer ();
       Fset_buffer (buf);
       if (!NILP (Ffboundp (intern ("minibuffer-inactive-mode"))))
         call0 (intern ("minibuffer-inactive-mode"));
diff --git a/src/nsmenu.m b/src/nsmenu.m
index e8a0b43a01b..ab285f26df2 100644
--- a/src/nsmenu.m
+++ b/src/nsmenu.m
@@ -1497,6 +1497,7 @@ ns_popup_dialog (Lisp_Object position, Lisp_Object contents, Lisp_Object header)
   FlippedView *contentView;
   NSImage *img;
 
+  dialog_return   = Qundefined;
   area.origin.x   = 3*SPACER;
   area.origin.y   = 2*SPACER;
   area.size.width = ICONSIZE;
@@ -1584,7 +1585,7 @@ ns_popup_dialog (Lisp_Object position, Lisp_Object contents, Lisp_Object header)
 
 - (BOOL)windowShouldClose: (id)sender
 {
-  [NSApp stopModalWithCode: XHASH (Qnil)]; // FIXME: BIG UGLY HACK!!
+  [NSApp stop:self];
   return NO;
 }
 
@@ -1673,7 +1674,11 @@ void process_dialog (id window, Lisp_Object list)
 
   seltag = [[sellist objectAtIndex: 0] tag];
   if (seltag != XHASH (Qundefined)) // FIXME: BIG UGLY HACK!!
-    [NSApp stopModalWithCode: seltag];
+    {
+      dialog_return = seltag;
+      [NSApp stop:self];
+    }
+
   return self;
 }
 
@@ -1756,13 +1761,27 @@ void process_dialog (id window, Lisp_Object list)
  
 - (void)timeout_handler: (NSTimer *)timedEntry
 {
+  NSEvent *nxev = [NSEvent otherEventWithType: NSApplicationDefined
+                            location: NSMakePoint (0, 0)
+                       modifierFlags: 0
+                           timestamp: 0
+                        windowNumber: [[NSApp mainWindow] windowNumber]
+                             context: [NSApp context]
+                             subtype: 0
+                               data1: 0
+                               data2: 0];
+
   timer_fired = 1;
-  [NSApp abortModal];
+  /* We use sto because stopModal/abortModal out of the main loop does not
+     seem to work in 10.6.  But as we use stop we must send a real event so
+     the stop is seen and acted upon.  */
+  [NSApp stop:self];
+  [NSApp postEvent: nxev atStart: NO];
 }
 
 - (Lisp_Object)runDialogAt: (NSPoint)p
 {
-  NSInteger ret = 0;
+  Lisp_Object ret = Qundefined;
 
   while (popup_activated_flag)
     {
@@ -1781,7 +1800,9 @@ void process_dialog (id window, Lisp_Object list)
                                        forMode: NSModalPanelRunLoopMode];
         }
       timer_fired = 0;
+      dialog_return = Qundefined;
       ret = [NSApp runModalForWindow: self];
+      ret = dialog_return;
       if (! timer_fired)
         {
           if (tmo != nil) [tmo invalidate]; /* Cancels timer */
diff --git a/src/nsterm.h b/src/nsterm.h
index 54f4a4ec89e..72b8d13cc47 100644
--- a/src/nsterm.h
+++ b/src/nsterm.h
@@ -196,6 +196,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    NSMatrix *matrix;
    int rows, cols;
    int timer_fired;
+   Lisp_Object dialog_return;
    }
 - initFromContents: (Lisp_Object)menu isQuestion: (BOOL)isQ;
 - addButton: (char *)str value: (Lisp_Object)val row: (int)row;
diff --git a/src/nsterm.m b/src/nsterm.m
index 12ca52684e6..c892a5486a7 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -5091,7 +5091,8 @@ not_in_argv (NSString *arg)
       /* TODO: still need this? */
       if (code == 0x2DC)
         code = '~'; /* 0x7E */
-      emacs_event->modifiers = 0;
+      if (code != 32) /* Space */
+        emacs_event->modifiers = 0;
       emacs_event->kind
         = code > 0xFF ? MULTIBYTE_CHAR_KEYSTROKE_EVENT : ASCII_KEYSTROKE_EVENT;
       emacs_event->code = code;
diff --git a/src/print.c b/src/print.c
index 64449aeaf2a..52c07c79122 100644
--- a/src/print.c
+++ b/src/print.c
@@ -197,8 +197,7 @@ int print_output_debug_flag EXTERNALLY_VISIBLE = 1;
                                ? PT - start_point : 0),                 \
                   old_point_byte + (old_point_byte >= start_point_byte  \
                                     ? PT_BYTE - start_point_byte : 0)); \
-   if (old != current_buffer)                                           \
-     set_buffer_internal (old);
+   set_buffer_internal (old);
 
 #define PRINTCHAR(ch) printchar (ch, printcharfun)
 
@@ -488,7 +487,7 @@ temp_output_buffer_setup (const char *bufname)
   register struct buffer *old = current_buffer;
   register Lisp_Object buf;
 
-  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
+  record_unwind_current_buffer ();
 
   Fset_buffer (Fget_buffer_create (build_string (bufname)));
 
diff --git a/src/process.c b/src/process.c
index 7f6f6bafbea..fbe56ebcb54 100644
--- a/src/process.c
+++ b/src/process.c
@@ -4870,15 +4870,13 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
       for (channel = 0; channel <= max_input_desc; ++channel)
         {
           struct fd_callback_data *d = &fd_callback_info[channel];
-          if (FD_ISSET (channel, &Available)
-              && d->func != 0
-              && (d->condition & FOR_READ) != 0)
-            d->func (channel, d->data, 1);
-          if (FD_ISSET (channel, &write_mask)
-              && d->func != 0
-              && (d->condition & FOR_WRITE) != 0)
-            d->func (channel, d->data, 0);
-          }
+          if (d->func
+              && ((d->condition & FOR_READ
+                   && FD_ISSET (channel, &Available))
+                  || (d->condition & FOR_WRITE
+                      && FD_ISSET (channel, &write_mask))))
+            d->func (channel, d->data);
+        }
 
       for (channel = 0; channel <= max_process_desc; channel++)
         {
@@ -5198,7 +5196,7 @@ read_process_output (Lisp_Object proc, register int channel)
   /* There's no good reason to let process filters change the current
      buffer, and many callers of accept-process-output, sit-for, and
      friends don't expect current-buffer to be changed from under them.  */
-  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
+  record_unwind_current_buffer ();
 
   /* Read and dispose of the process output.  */
   outstream = p->filter;
@@ -6589,7 +6587,7 @@ exec_sentinel (Lisp_Object proc, Lisp_Object reason)
   /* There's no good reason to let sentinels change the current
      buffer, and many callers of accept-process-output, sit-for, and
      friends don't expect current-buffer to be changed from under them.  */
-  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
+  record_unwind_current_buffer ();
 
   sentinel = p->sentinel;
   if (NILP (sentinel))
diff --git a/src/process.h b/src/process.h
index 55a572117c6..ce3d2e702cc 100644
--- a/src/process.h
+++ b/src/process.h
@@ -184,7 +184,7 @@ pset_gnutls_cred_type (struct Lisp_Process *p, Lisp_Object val)
 
 /* True if we are about to fork off a synchronous process or if we
    are waiting for it.  */
-extern int synch_process_alive;
+extern bool synch_process_alive;
 
 /* Communicate exit status of sync process to from sigchld_handler
    to Fcall_process.  */
@@ -219,7 +219,7 @@ extern void hold_keyboard_input (void);
 extern void unhold_keyboard_input (void);
 extern int kbd_on_hold_p (void);
 
-typedef void (*fd_callback)(int fd, void *data, int for_read);
+typedef void (*fd_callback) (int fd, void *data);
 
 extern void add_read_fd (int fd, fd_callback func, void *data);
 extern void delete_read_fd (int fd);
diff --git a/src/textprop.c b/src/textprop.c
index 20d98b0e6f3..b6895fc426a 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -760,7 +760,7 @@ past position LIMIT; return LIMIT if nothing is found before LIMIT.  */)
 
       if (BUFFERP (object) && current_buffer != XBUFFER (object))
         {
-          record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+          record_unwind_current_buffer ();
           Fset_buffer (object);
         }
 
@@ -843,7 +843,7 @@ position LIMIT; return LIMIT if nothing is found before reaching LIMIT.  */)
 
       if (BUFFERP (object) && current_buffer != XBUFFER (object))
         {
-          record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+          record_unwind_current_buffer ();
           Fset_buffer (object);
         }
 
diff --git a/src/undo.c b/src/undo.c
index 777e3291806..9cd1d5f9f67 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -324,7 +324,7 @@ truncate_undo_list (struct buffer *b)
   /* Make the buffer current to get its local values of variables such
      as undo_limit.  Also so that Vundo_outer_limit_function can
      tell which buffer to operate on.  */
-  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
+  record_unwind_current_buffer ();
   set_buffer_internal (b);
 
   list = BVAR (b, undo_list);
diff --git a/src/w32.c b/src/w32.c
index b460660cb8c..84a46e522bb 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -4098,7 +4098,7 @@ symlink (char const *filename, char const *linkname)
     dir_access = sys_access (filename, D_OK);
 
   /* Since Windows distinguishes between symlinks to directories and
-     to files, we provide a kludgey feature: if FILENAME doesn't
+     to files, we provide a kludgy feature: if FILENAME doesn't
      exist, but ends in a slash, we create a symlink to directory.  If
      FILENAME exists and is a directory, we always create a symlink to
      directory.  */
@@ -4165,7 +4165,7 @@ symlink (char const *filename, char const *linkname)
    whether the underlying volume actually supports symlinks, by
    testing the FILE_SUPPORTS_REPARSE_POINTS bit in volume's flags, and
    avoid the call to this function if it doesn't.  That's because the
-   call to GetFileAttributes takes a non-negligible time, expecially
+   call to GetFileAttributes takes a non-negligible time, especially
    on non-local or removable filesystems.  See stat_worker for an
    example of how to do that.  */
 static int
diff --git a/src/window.c b/src/window.c
index 4d92566b243..ba1ec2544f8 100644
--- a/src/window.c
+++ b/src/window.c
@@ -54,7 +54,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "nsterm.h"
 #endif
 
-Lisp_Object Qwindowp, Qwindow_live_p, Qwindow_valid_p;
+Lisp_Object Qwindowp, Qwindow_live_p;
+static Lisp_Object Qwindow_valid_p;
 static Lisp_Object Qwindow_configuration_p, Qrecord_window_buffer;
 static Lisp_Object Qwindow_deletable_p, Qdelete_window, Qdisplay_buffer;
 static Lisp_Object Qreplace_buffer_in_windows, Qget_mru_window;
@@ -268,7 +269,7 @@ decode_any_window (register Lisp_Object window)
   return w;
 }
 
-struct window *
+static struct window *
 decode_valid_window (register Lisp_Object window)
 {
   struct window *w;
@@ -1968,6 +1969,9 @@ unshow_buffer (register struct window *w)
      is actually stored in that buffer, and the window's pointm isn't used.
      So don't clobber point in that buffer.  */
   if (! EQ (buf, XWINDOW (selected_window)->buffer)
+      /* Don't clobber point in current buffer either (this could be
+         useful in connection with bug#12208).
+      && XBUFFER (buf) != current_buffer  */
       /* This line helps to fix Horsley's testbug.el bug.  */
       && !(WINDOWP (BVAR (b, last_selected_window))
            && w != XWINDOW (BVAR (b, last_selected_window))
@@ -3097,7 +3101,7 @@ run_window_configuration_change_hook (struct frame *f)
   /* Use the right buffer.  Matters when running the local hooks.  */
   if (current_buffer != XBUFFER (Fwindow_buffer (Qnil)))
     {
-      record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+      record_unwind_current_buffer ();
       Fset_buffer (Fwindow_buffer (Qnil));
     }
 
@@ -3134,7 +3138,7 @@ run_window_configuration_change_hook (struct frame *f)
 DEFUN ("run-window-configuration-change-hook", Frun_window_configuration_change_hook,
        Srun_window_configuration_change_hook, 1, 1, 0,
        doc: /* Run `window-configuration-change-hook' for FRAME.  */)
-     (Lisp_Object frame)
+  (Lisp_Object frame)
 {
   CHECK_LIVE_FRAME (frame);
   run_window_configuration_change_hook (XFRAME (frame));
@@ -3201,7 +3205,7 @@ set_window_buffer (Lisp_Object window, Lisp_Object buffer, int run_hooks_p, int
      because that might itself be a local variable.  */
   if (window_initialized)
     {
-      record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+      record_unwind_current_buffer ();
       Fset_buffer (buffer);
     }
 
@@ -5899,7 +5903,13 @@ the return value is nil.  Otherwise the value is t.  */)
     }
 
   if (!NILP (new_current_buffer))
-    Fset_buffer (new_current_buffer);
+    {
+      Fset_buffer (new_current_buffer);
+      /* If the new current buffer doesn't appear in the selected
+         window, go to its old point (see bug#12208).  */
+      if (!EQ (XWINDOW (data->current_window)->buffer, new_current_buffer))
+        Fgoto_char (make_number (old_point));
+    }
 
   Vminibuf_scroll_window = data->minibuf_scroll_window;
   minibuf_selected_window = data->minibuf_selected_window;
diff --git a/src/window.h b/src/window.h
index 28b9678b667..dfb88b2cf3c 100644
--- a/src/window.h
+++ b/src/window.h
@@ -972,7 +972,6 @@ struct glyph *get_phys_cursor_glyph (struct window *w);
 extern Lisp_Object Qwindowp, Qwindow_live_p;
 extern Lisp_Object Vwindow_list;
 
-extern struct window *decode_valid_window (Lisp_Object);
 extern struct window *decode_live_window (Lisp_Object);
 extern int compare_window_configurations (Lisp_Object, Lisp_Object, int);
 extern void mark_window_cursors_off (struct window *);
diff --git a/src/xdisp.c b/src/xdisp.c
index f5edb4b16f8..13b03736bde 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -2420,7 +2420,7 @@ remember_mouse_glyph (struct frame *f, int gx, int gy, NativeRectangle *rect)
 static Lisp_Object
 safe_eval_handler (Lisp_Object arg, ptrdiff_t nargs, Lisp_Object *args)
 {
-  add_to_log ("Error during redisplay: %S signalled %S",
+  add_to_log ("Error during redisplay: %S signaled %S",
               Flist (nargs, args), arg);
   return Qnil;
 }
@@ -14551,8 +14551,7 @@ run_window_scroll_functions (Lisp_Object window, struct text_pos startp)
                             make_number (CHARPOS (startp)));
       SET_TEXT_POS_FROM_MARKER (startp, w->start);
       /* In case the hook functions switch buffers.  */
-      if (current_buffer != XBUFFER (w->buffer))
-        set_buffer_internal_1 (XBUFFER (w->buffer));
+      set_buffer_internal (XBUFFER (w->buffer));
     }
 
   return startp;
@@ -15380,7 +15379,7 @@ set_vertical_scroll_bar (struct window *w)
    selected_window is redisplayed.
 
    We can return without actually redisplaying the window if
-   fonts_changed_p is nonzero.  In that case, redisplay_internal will
+   fonts_changed_p.  In that case, redisplay_internal will
    retry.  */
 
 static void
@@ -16224,7 +16223,7 @@ redisplay_window (Lisp_Object window, int just_this_one_p)
     }
 #endif /* HAVE_WINDOW_SYSTEM */
 
-  /* We go to this label, with fonts_changed_p nonzero,
+  /* We go to this label, with fonts_changed_p set,
      if it is necessary to try again using larger glyph matrices.
      We have to redeem the scroll bar even in this case,
      because the loop in redisplay_internal expects that.  */
@@ -17705,15 +17704,15 @@ try_window_id (struct window *w)
     {
       rotate_matrix (current_matrix, first_unchanged_at_end_vpos + dvpos,
                      bottom_vpos, dvpos);
-      enable_glyph_matrix_rows (current_matrix, bottom_vpos + dvpos,
-                                bottom_vpos, 0);
+      clear_glyph_matrix_rows (current_matrix, bottom_vpos + dvpos,
+                               bottom_vpos);
     }
   else if (dvpos > 0)
     {
       rotate_matrix (current_matrix, first_unchanged_at_end_vpos,
                      bottom_vpos, dvpos);
-      enable_glyph_matrix_rows (current_matrix, first_unchanged_at_end_vpos,
-                                first_unchanged_at_end_vpos + dvpos, 0);
+      clear_glyph_matrix_rows (current_matrix, first_unchanged_at_end_vpos,
+                               first_unchanged_at_end_vpos + dvpos);
     }
 
   /* For frame-based redisplay, make sure that current frame and window
diff --git a/src/xgselect.c b/src/xgselect.c
index 04ca00274e8..0c00d815820 100644
--- a/src/xgselect.c
+++ b/src/xgselect.c
@@ -29,9 +29,6 @@ along with GNU Emacs.  If not, see <http§://www.gnu.org/licenses/>.  */
 #include <setjmp.h>
 #include "xterm.h"
 
-static GPollFD *gfds;
-static ptrdiff_t gfds_size;
-
 int
 xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
            EMACS_TIME *timeout, sigset_t *sigmask)
@@ -41,35 +38,31 @@ xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
 
   GMainContext *context;
   int have_wfds = wfds != NULL;
-  int n_gfds = 0, retval = 0, our_fds = 0, max_fds = fds_lim - 1;
+  GPollFD gfds_buf[128];
+  GPollFD *gfds = gfds_buf;
+  int gfds_size = sizeof gfds_buf / sizeof *gfds_buf;
+  int n_gfds, retval = 0, our_fds = 0, max_fds = fds_lim - 1;
   int i, nfds, tmo_in_millisec;
+  USE_SAFE_ALLOCA;
 
-  if (!x_in_use)
-    return pselect (fds_lim, rfds, wfds, efds, tmop, sigmask);
+  if (! (x_in_use
+         && g_main_context_pending (context = g_main_context_default ())))
+    return pselect (fds_lim, rfds, wfds, efds, timeout, sigmask);
 
   if (rfds) memcpy (&all_rfds, rfds, sizeof (all_rfds));
   else FD_ZERO (&all_rfds);
   if (wfds) memcpy (&all_wfds, wfds, sizeof (all_rfds));
   else FD_ZERO (&all_wfds);
 
-  /* Update event sources in GLib. */
-  context = g_main_context_default ();
-  g_main_context_pending (context);
-
-  do {
-    if (n_gfds > gfds_size)
-      {
-        xfree (gfds);
-        gfds = xpalloc (0, &gfds_size, n_gfds - gfds_size, INT_MAX,
-                        sizeof *gfds);
-      }
-
-    n_gfds = g_main_context_query (context,
-                                   G_PRIORITY_LOW,
-                                   &tmo_in_millisec,
-                                   gfds,
-                                   gfds_size);
-  } while (n_gfds > gfds_size);
+  n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec,
+                                 gfds, gfds_size);
+  if (gfds_size < n_gfds)
+    {
+      SAFE_NALLOCA (gfds, sizeof *gfds, n_gfds);
+      gfds_size = n_gfds;
+      n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec,
+                                     gfds, gfds_size);
+    }
 
   for (i = 0; i < n_gfds; ++i)
     {
@@ -86,6 +79,8 @@ xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
         }
     }
 
+  SAFE_FREE ();
+
   if (tmo_in_millisec >= 0)
     {
       tmo = make_emacs_time (tmo_in_millisec / 1000,
@@ -147,12 +142,3 @@ xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
   return retval;
 }
 #endif /* USE_GTK || HAVE_GCONF || HAVE_GSETTINGS */
-
-void
-xgselect_initialize (void)
-{
-#if defined (USE_GTK) || defined (HAVE_GCONF) || defined (HAVE_GSETTINGS)
-  gfds_size = 128;
-  gfds = xmalloc (gfds_size * sizeof *gfds);
-#endif
-}
diff --git a/src/xgselect.h b/src/xgselect.h
index 8e5614ea972..5509e23c5c0 100644
--- a/src/xgselect.h
+++ b/src/xgselect.h
@@ -31,6 +31,4 @@ extern int xg_select (int max_fds,
                       EMACS_TIME *timeout,
                       sigset_t *sigmask);
 
-extern void xgselect_initialize (void);
-
 #endif /* XGSELECT_H */
diff --git a/src/xsmfns.c b/src/xsmfns.c
index 1f6eb84260e..cddbb2aae86 100644
--- a/src/xsmfns.c
+++ b/src/xsmfns.c
@@ -97,7 +97,7 @@ ice_connection_closed (void)
    open to a session manager, just return.  */
 
 static void
-x_session_check_input (int fd, void *data, int for_read)
+x_session_check_input (int fd, void *data)
 {
   int ret;
 
diff --git a/src/xterm.c b/src/xterm.c
index 118c8767c23..7e61cc4d8ea 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -10815,8 +10815,6 @@ x_initialize (void)
   XSetIOErrorHandler (x_io_error_quitter);
 
   signal (SIGPIPE, x_connection_signal);
-
-  xgselect_initialize ();
 }