117 files changed, 463 insertions, 966 deletions
diff --git a/src/Makefile.in b/src/Makefile.in
index a84fdd1caf8..cdae2c89fa1 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -264,9 +264,6 @@ MSDOS_OBJ =
 ## w16select.o termcap.o if MSDOS && HAVE_X_WINDOWS.
 MSDOS_X_OBJ =
-ns_appdir=@ns_appdir@
-ns_appbindir=@ns_appbindir@
-ns_appsrc=@ns_appsrc@
 NS_OBJ=@NS_OBJ@
 ## nsterm.o nsfns.o nsmenu.o nsselect.o nsimage.o nsfont.o if HAVE_NS.
 NS_OBJC_OBJ=@NS_OBJC_OBJ@
@@ -514,8 +511,9 @@ $(OLDXMENU): $(OLDXMENU_TARGET)
 doc.o: buildobj.h
-## If HAVE_NS, some ns-specific rules (for OTHER_FILES) are inserted here.
+ns-app: emacs$(EXEEXT)
-@ns_frag@
+        cd ../nextstep && $(MAKE) $(MFLAGS) all
 .PHONY: mostlyclean clean bootstrap-clean distclean maintainer-clean
 .PHONY: versionclean extraclean frc
@@ -529,7 +527,6 @@ mostlyclean:
 clean: mostlyclean
        rm -f emacs-*.*.*$(EXEEXT) emacs$(EXEEXT)
        -rm -rf $(DEPDIR)
-        test "X$(ns_appdir)" = "X" || rm -rf $(ns_appdir)
 ## bootstrap-clean is used to clean up just before a bootstrap.
 ## It should remove all files generated during a compilation/bootstrap,
diff --git a/src/atimer.c b/src/atimer.c
index 34731920af5..5dbd807872a 100644
--- a/src/atimer.c
+++ b/src/atimer.c
@@ -18,7 +18,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "syssignal.h"
 #include "systime.h"
@@ -369,7 +369,6 @@ run_timers (void)
  if (! atimers)
    pending_atimers = 0;
-#ifdef SYNC_INPUT
  if (pending_atimers)
    pending_signals = 1;
  else
@@ -377,10 +376,6 @@ run_timers (void)
      pending_signals = interrupt_input_pending;
      set_alarm ();
    }
-#else
-  if (! pending_atimers)
-    set_alarm ();
-#endif
 }
@@ -391,11 +386,7 @@ static void
 handle_alarm_signal (int sig)
 {
  pending_atimers = 1;
-#ifdef SYNC_INPUT
  pending_signals = 1;
-#else
-  run_timers ();
-#endif
 }
 static void
diff --git a/src/bidi.c b/src/bidi.c
index 4186a46e19e..af0209565e2 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -56,7 +56,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/blockinput.h b/src/blockinput.h
index 3f61b2b27b9..7501bfc91a0 100644
--- a/src/blockinput.h
+++ b/src/blockinput.h
@@ -67,15 +67,10 @@ extern int pending_atimers;
   If doing signal-driven input, and a signal came in when input was
   blocked, reinvoke the signal handler now to deal with it.
-   We used to have two possible definitions of this macro - one for
+   Always test interrupt_input_pending; that's not too expensive, and
-   when SIGIO was #defined, and one for when it wasn't; when SIGIO
+   it'll never get set if we don't need to resignal.  This is simpler
-   wasn't #defined, we wouldn't bother to check if we should re-invoke
+   than dealing here with every configuration option that might affect
-   the signal handler.  But that doesn't work very well; some of the
+   whether interrupt_input_pending can be nonzero.  */
-   files which use this macro don't #include the right files to get
-   SIGIO.
-   So, we always test interrupt_input_pending now; that's not too
-   expensive, and it'll never get set if we don't need to resignal.  */
 #define UNBLOCK_INPUT                           \
  do                                            \
diff --git a/src/buffer.c b/src/buffer.c
index d512547d34e..b020edb9962 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -26,7 +26,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/param.h>
 #include <errno.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <unistd.h>
 #include <verify.h>
diff --git a/src/bytecode.c b/src/bytecode.c
index 97730636d0e..5f4fdcc5eff 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -33,7 +33,7 @@ by Hallvard:
 */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
@@ -458,7 +458,8 @@ unmark_byte_stack (void)
        Fsignal (Qquit, Qnil);                          \
        AFTER_POTENTIAL_GC ();                          \
      }                                                 \
-    ELSE_PENDING_SIGNALS                                \
+    else if (pending_signals)                           \
+      process_pending_signals ();                       \
  } while (0)
diff --git a/src/callint.c b/src/callint.c
index b11545ddea2..c4c087e83d7 100644
--- a/src/callint.c
+++ b/src/callint.c
@@ -19,7 +19,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/callproc.c b/src/callproc.c
index a92959a1559..2604d295f3e 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <errno.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -497,11 +496,6 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
    register char **save_environ = environ;
    register int fd1 = fd[1];
    int fd_error = fd1;
-#ifdef HAVE_WORKING_VFORK
-    sigset_t procmask;
-    sigset_t blocked;
-    struct sigaction sigpipe_action;
-#endif
    if (fd_output >= 0)
      fd1 = fd_output;
@@ -588,17 +582,6 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
                       0, current_dir);
 #else  /* not WINDOWSNT */
-#ifdef HAVE_WORKING_VFORK
-    /* On many hosts (e.g. Solaris 2.4), if a vforked child calls `signal',
-       this sets the parent's signal handlers as well as the child's.
-       So delay all interrupts whose handlers the child might munge,
-       and record the current handlers so they can be restored later.  */
-    sigemptyset (&blocked);
-    sigaddset (&blocked, SIGPIPE);
-    sigaction (SIGPIPE, 0, &sigpipe_action);
-    pthread_sigmask (SIG_BLOCK, &blocked, &procmask);
-#endif
    BLOCK_INPUT;
    /* vfork, and prevent local vars from being clobbered by the vfork.  */
@@ -646,9 +629,6 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
        /* GConf causes us to ignore SIGPIPE, make sure it is restored
           in the child.  */
        signal (SIGPIPE, SIG_DFL);
-#ifdef HAVE_WORKING_VFORK
-        pthread_sigmask (SIG_SETMASK, &procmask, 0);
-#endif
        child_setup (filefd, fd1, fd_error, (char **) new_argv,
                     0, current_dir);
@@ -656,12 +636,6 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
    UNBLOCK_INPUT;
-#ifdef HAVE_WORKING_VFORK
-    /* Restore the signal state.  */
-    sigaction (SIGPIPE, &sigpipe_action, 0);
-    pthread_sigmask (SIG_SETMASK, &procmask, 0);
-#endif
 #endif /* not WINDOWSNT */
    /* The MSDOS case did this already.  */
diff --git a/src/casefiddle.c b/src/casefiddle.c
index 1102054b153..e3654627576 100644
--- a/src/casefiddle.c
+++ b/src/casefiddle.c
@@ -19,7 +19,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
diff --git a/src/casetab.c b/src/casetab.c
index 3e22d0d0b77..a84bc9202d0 100644
--- a/src/casetab.c
+++ b/src/casetab.c
@@ -19,7 +19,7 @@ You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
diff --git a/src/category.c b/src/category.c
index 80dc6938d8b..01a6f54ad17 100644
--- a/src/category.c
+++ b/src/category.c
@@ -32,7 +32,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define CATEGORY_INLINE EXTERN_INLINE
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
diff --git a/src/ccl.c b/src/ccl.c
index dd37934451d..34cc1c98eea 100644
--- a/src/ccl.c
+++ b/src/ccl.c
@@ -26,7 +26,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <limits.h>
 #include "lisp.h"
diff --git a/src/character.c b/src/character.c
index 37963d1878c..def1ad090fd 100644
--- a/src/character.c
+++ b/src/character.c
@@ -36,7 +36,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #ifdef emacs
 #include <sys/types.h>
-#include <setjmp.h>
 #include <intprops.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/charset.c b/src/charset.c
index 972a0598059..d8c38e5ea3b 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -32,7 +32,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <unistd.h>
 #include <limits.h>
 #include <sys/types.h>
-#include <setjmp.h>
 #include <c-ctype.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/chartab.c b/src/chartab.c
index c14df0ebac6..e864514e336 100644
--- a/src/chartab.c
+++ b/src/chartab.c
@@ -19,7 +19,7 @@ You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "charset.h"
diff --git a/src/cm.c b/src/cm.c
index 4b17b92eebc..eda6430bafa 100644
--- a/src/cm.c
+++ b/src/cm.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "frame.h"
diff --git a/src/cmds.c b/src/cmds.c
index 90d3cd6dced..45f7df948ae 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -19,7 +19,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "commands.h"
 #include "character.h"
diff --git a/src/coding.c b/src/coding.c
index 94a2d9fea80..4b3d22f956c 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -285,7 +285,6 @@ encode_coding_XXX (struct coding_system *coding)
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/composite.c b/src/composite.c
index eddabb66d33..ae46df0a573 100644
--- a/src/composite.c
+++ b/src/composite.c
@@ -26,7 +26,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define COMPOSITE_INLINE EXTERN_INLINE
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
diff --git a/src/conf_post.h b/src/conf_post.h
index 1bf40af260b..0c4d029bc5d 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -90,7 +90,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 char *_getpty();
 #endif
-#undef SA_RESTART     /* not the same as defining BROKEN_SA_RESTART */
 #endif /* IRIX6_5 */
 #ifdef MSDOS
@@ -133,22 +132,6 @@ You lose; /* Emacs for DOS must be compiled with DJGPP */
 #endif
 #endif  /* MSDOS */
-#ifdef USG5_4
-/* Get FIONREAD from <sys/filio.h>.  Get <sys/ttold.h> to get struct tchars.
-   But get <termio.h> first to make sure ttold.h doesn't interfere.  */
-#include <sys/wait.h>
-#ifdef emacs
-#include <sys/filio.h>
-#include <termio.h>
-#include <sys/ttold.h>
-#include <signal.h>
-#include <sys/stream.h>
-#include <sys/stropts.h>
-#include <sys/termios.h>
-#endif
-#endif  /* USG5_4 */
 /* Mac OS X / GNUstep need a bit more pure memory.  Of the existing knobs,
   SYSTEM_PURESIZE_EXTRA seems like the least likely to cause problems.  */
 #ifdef HAVE_NS
diff --git a/src/data.c b/src/data.c
index 5d7f036b70d..72d7c8ccf9a 100644
--- a/src/data.c
+++ b/src/data.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <intprops.h>
diff --git a/src/dbusbind.c b/src/dbusbind.c
index 901820648cb..c2eefd605bb 100644
--- a/src/dbusbind.c
+++ b/src/dbusbind.c
@@ -21,7 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #ifdef HAVE_DBUS
 #include <stdio.h>
 #include <dbus/dbus.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "frame.h"
 #include "termhooks.h"
diff --git a/src/dired.c b/src/dired.c
index 9af5f76821b..3aa27ecf920 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <setjmp.h>
 #ifdef HAVE_PWD_H
 #include <pwd.h>
diff --git a/src/dispextern.h b/src/dispextern.h
index 11243d23db9..6f5cd55504b 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -3221,6 +3221,7 @@ void unrequest_sigio (void);
 int tabs_safe_p (int);
 void init_baud_rate (int);
 void init_sigio (int);
+void ignore_sigio (void);
 /* Defined in xfaces.c */
diff --git a/src/dispnew.c b/src/dispnew.c
index bc9141a575d..9cc7349f1b0 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define DISPEXTERN_INLINE EXTERN_INLINE
 #include <stdio.h>
-#include <setjmp.h>
 #include <unistd.h>
 #include "lisp.h"
@@ -5982,7 +5981,7 @@ sit_for (Lisp_Object timeout, bool reading, int do_display)
    wrong_type_argument (Qnumberp, timeout);
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  gobble_input (0);
 #endif
diff --git a/src/doc.c b/src/doc.c
index 02a5b4b8143..d2d664df266 100644
--- a/src/doc.c
+++ b/src/doc.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/types.h>
 #include <sys/file.h>   /* Must be after sys/types.h for USG*/
-#include <setjmp.h>
 #include <fcntl.h>
 #include <unistd.h>
diff --git a/src/doprnt.c b/src/doprnt.c
index 3b7391f07d4..caa56d6ae88 100644
--- a/src/doprnt.c
+++ b/src/doprnt.c
@@ -102,7 +102,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <float.h>
 #include <unistd.h>
 #include <limits.h>
diff --git a/src/dosfns.c b/src/dosfns.c
index 21676f4b4f5..3c649f4d534 100644
--- a/src/dosfns.c
+++ b/src/dosfns.c
@@ -30,7 +30,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <dos.h>
 #undef gettime
 #undef settime
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
diff --git a/src/editfns.c b/src/editfns.c
index 299cad07fd7..c6744648bc5 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <sys/types.h>
 #include <stdio.h>
-#include <setjmp.h>
 #ifdef HAVE_PWD_H
 #include <pwd.h>
diff --git a/src/emacs.c b/src/emacs.c
index d0e2f1e021d..7e4f25abe6e 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -25,7 +25,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/types.h>
 #include <sys/file.h>
-#include <setjmp.h>
 #include <unistd.h>
 #include "lisp.h"
@@ -92,7 +91,7 @@ extern void moncontrol (int mode);
 #endif
 static const char emacs_version[] = VERSION;
-static const char emacs_copyright[] = "Copyright (C) 2012 Free Software Foundation, Inc.";
+static const char emacs_copyright[] = COPYRIGHT;
 /* Empty lisp strings.  To avoid having to build any others.  */
 Lisp_Object empty_unibyte_string, empty_multibyte_string;
@@ -852,14 +851,10 @@ main (int argc, char **argv)
  /* Arrange to get warning messages as memory fills up.  */
  memory_warnings (0, malloc_warning);
-  /* Call malloc at least once, to run the initial __malloc_hook.
+  /* Call malloc at least once, to run malloc_initialize_hook.
     Also call realloc and free for consistency.  */
  free (realloc (malloc (4), 4));
-# ifndef SYNC_INPUT
-  /* Arrange to disable interrupt input inside malloc etc.  */
-  uninterrupt_malloc ();
-# endif /* not SYNC_INPUT */
 #endif  /* not SYSTEM_MALLOC */
 #if defined (MSDOS) || defined (WINDOWSNT)
@@ -2041,12 +2036,10 @@ shut_down_emacs (int sig, Lisp_Object stuff)
  unlock_all_files ();
 #endif
-#ifdef SIGIO
  /* There is a tendency for a SIGIO signal to arrive within exit,
     and cause a SIGHUP because the input descriptor is already closed.  */
  unrequest_sigio ();
-  signal (SIGIO, SIG_IGN);
+  ignore_sigio ();
-#endif
 #ifdef WINDOWSNT
  term_ntproc ();
@@ -2152,12 +2145,6 @@ You must run Emacs in batch mode in order to dump it.  */)
    memory_warnings (my_edata, malloc_warning);
  }
 #endif /* not WINDOWSNT */
-#if defined (HAVE_PTHREAD) && !defined SYNC_INPUT
-  /* Pthread may call malloc before main, and then we will get an endless
-     loop, because pthread_self (see alloc.c) calls malloc the first time
-     it is called on some systems.  */
-  reset_malloc_hooks ();
-#endif
 #endif /* not SYSTEM_MALLOC */
 #ifdef DOUG_LEA_MALLOC
  malloc_state_ptr = malloc_get_state ();
diff --git a/src/emacsgtkfixed.c b/src/emacsgtkfixed.c
index 5f90a5b90aa..d23f3e21f24 100644
--- a/src/emacsgtkfixed.c
+++ b/src/emacsgtkfixed.c
@@ -22,13 +22,40 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "emacsgtkfixed.h"
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "frame.h"
 #include "xterm.h"
 #ifdef HAVE_XWIDGETS
 #include "xwidget.h"
 #endif
+/* Silence a bogus diagnostic; see GNOME bug 683906.  */
+#if (__GNUC__ == 4 && 6 <= __GNUC_MINOR__) || 4 < __GNUC__
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wunused-local-typedefs"
+#endif
+#define EMACS_TYPE_FIXED emacs_fixed_get_type ()
+#define EMACS_FIXED(obj) \
+  G_TYPE_CHECK_INSTANCE_CAST (obj, EMACS_TYPE_FIXED, EmacsFixed)
+typedef struct _EmacsFixed EmacsFixed;
+typedef struct _EmacsFixedPrivate EmacsFixedPrivate;
+typedef struct _EmacsFixedClass EmacsFixedClass;
+struct _EmacsFixed
+{
+  GtkFixed container;
+  /*< private >*/
+  EmacsFixedPrivate *priv;
+};
+struct _EmacsFixedClass
+{
+  GtkFixedClass parent_class;
+};
 struct _EmacsFixedPrivate
 {
  struct frame *f;
diff --git a/src/eval.c b/src/eval.c
index 8a8a507a1b6..1c565e233c6 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -19,7 +19,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <limits.h>
-#include <setjmp.h>
 #include <stdio.h>
 #include "lisp.h"
 #include "blockinput.h"
@@ -118,12 +117,6 @@ static EMACS_INT when_entered_debugger;
 Lisp_Object Vsignaling_function;
-/* Set to non-zero while processing X events.  Checked in Feval to
-   make sure the Lisp interpreter isn't called from a signal handler,
-   which is unsafe because the interpreter isn't reentrant.  */
-int handling_signal;
 /* If non-nil, Lisp code must not be run since some part of Emacs is
   in an inconsistent state.  Currently, x-create-frame uses this to
   avoid triggering window-configuration-change-hook while the new
@@ -707,7 +700,7 @@ usage: (defvar SYMBOL &optional INITVALUE DOCSTRING)  */)
      else
        { /* Check if there is really a global binding rather than just a let
             binding that shadows the global unboundness of the var.  */
-          volatile struct specbinding *pdl = specpdl_ptr;
+          struct specbinding *pdl = specpdl_ptr;
          while (pdl > specpdl)
            {
              if (EQ ((--pdl)->symbol, sym) && !pdl->func
@@ -1072,7 +1065,7 @@ internal_catch (Lisp_Object tag, Lisp_Object (*func) (Lisp_Object), Lisp_Object
  catchlist = &c;
  /* Call FUNC.  */
-  if (! _setjmp (c.jmp))
+  if (! sys_setjmp (c.jmp))
    c.val = (*func) (arg);
  /* Throw works by a longjmp that comes right here.  */
@@ -1107,7 +1100,6 @@ unwind_to_catch (struct catchtag *catch, Lisp_Object value)
  /* Restore certain special C variables.  */
  set_poll_suppress_count (catch->poll_suppress_count);
  UNBLOCK_INPUT_TO (catch->interrupt_input_blocked);
-  handling_signal = 0;
  immediate_quit = 0;
  do
@@ -1140,7 +1132,7 @@ unwind_to_catch (struct catchtag *catch, Lisp_Object value)
  backtrace_list = catch->backlist;
  lisp_eval_depth = catch->lisp_eval_depth;
-  _longjmp (catch->jmp, 1);
+  sys_longjmp (catch->jmp, 1);
 }
 DEFUN ("throw", Fthrow, Sthrow, 2, 2, 0,
@@ -1204,12 +1196,9 @@ See also the function `signal' for more info.
 usage: (condition-case VAR BODYFORM &rest HANDLERS)  */)
  (Lisp_Object args)
 {
-  register Lisp_Object bodyform, handlers;
+  Lisp_Object var = Fcar (args);
-  volatile Lisp_Object var;
+  Lisp_Object bodyform = Fcar (Fcdr (args));
+  Lisp_Object handlers = Fcdr (Fcdr (args));
-  var      = Fcar (args);
-  bodyform = Fcar (Fcdr (args));
-  handlers = Fcdr (Fcdr (args));
  return internal_lisp_condition_case (var, bodyform, handlers);
 }
@@ -1249,7 +1238,7 @@ internal_lisp_condition_case (volatile Lisp_Object var, Lisp_Object bodyform,
  c.interrupt_input_blocked = interrupt_input_blocked;
  c.gcpro = gcprolist;
  c.byte_stack = byte_stack_list;
-  if (_setjmp (c.jmp))
+  if (sys_setjmp (c.jmp))
    {
      if (!NILP (h.var))
        specbind (h.var, c.val);
@@ -1304,7 +1293,7 @@ internal_condition_case (Lisp_Object (*bfun) (void), Lisp_Object handlers,
  c.interrupt_input_blocked = interrupt_input_blocked;
  c.gcpro = gcprolist;
  c.byte_stack = byte_stack_list;
-  if (_setjmp (c.jmp))
+  if (sys_setjmp (c.jmp))
    {
      return (*hfun) (c.val);
    }
@@ -1342,7 +1331,7 @@ internal_condition_case_1 (Lisp_Object (*bfun) (Lisp_Object), Lisp_Object arg,
  c.interrupt_input_blocked = interrupt_input_blocked;
  c.gcpro = gcprolist;
  c.byte_stack = byte_stack_list;
-  if (_setjmp (c.jmp))
+  if (sys_setjmp (c.jmp))
    {
      return (*hfun) (c.val);
    }
@@ -1384,7 +1373,7 @@ internal_condition_case_2 (Lisp_Object (*bfun) (Lisp_Object, Lisp_Object),
  c.interrupt_input_blocked = interrupt_input_blocked;
  c.gcpro = gcprolist;
  c.byte_stack = byte_stack_list;
-  if (_setjmp (c.jmp))
+  if (sys_setjmp (c.jmp))
    {
      return (*hfun) (c.val);
    }
@@ -1428,7 +1417,7 @@ internal_condition_case_n (Lisp_Object (*bfun) (ptrdiff_t, Lisp_Object *),
  c.interrupt_input_blocked = interrupt_input_blocked;
  c.gcpro = gcprolist;
  c.byte_stack = byte_stack_list;
-  if (_setjmp (c.jmp))
+  if (sys_setjmp (c.jmp))
    {
      return (*hfun) (c.val, nargs, args);
    }
@@ -1490,7 +1479,7 @@ See also the function `condition-case'.  */)
  struct handler *h;
  struct backtrace *bp;
-  immediate_quit = handling_signal = 0;
+  immediate_quit = 0;
  abort_on_gc = 0;
  if (gc_in_progress || waiting_for_input)
    emacs_abort ();
@@ -2043,9 +2032,6 @@ eval_sub (Lisp_Object form)
  struct backtrace backtrace;
  struct gcpro gcpro1, gcpro2, gcpro3;
-  if (handling_signal)
-    emacs_abort ();
  if (SYMBOLP (form))
    {
      /* Look up its binding in the lexical environment.
@@ -3108,8 +3094,6 @@ specbind (Lisp_Object symbol, Lisp_Object value)
 {
  struct Lisp_Symbol *sym;
-  eassert (!handling_signal);
  CHECK_SYMBOL (symbol);
  sym = XSYMBOL (symbol);
  if (specpdl_ptr == specpdl + specpdl_size)
@@ -3203,8 +3187,6 @@ specbind (Lisp_Object symbol, Lisp_Object value)
 void
 record_unwind_protect (Lisp_Object (*function) (Lisp_Object), Lisp_Object arg)
 {
-  eassert (!handling_signal);
  if (specpdl_ptr == specpdl + specpdl_size)
    grow_specpdl ();
  specpdl_ptr->func = function;
diff --git a/src/fileio.c b/src/fileio.c
index f0b3f0cc2fd..ca71af7ed95 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -23,7 +23,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <setjmp.h>
 #include <unistd.h>
 #ifdef HAVE_PWD_H
diff --git a/src/filelock.c b/src/filelock.c
index 1f599c68912..17f3f253249 100644
--- a/src/filelock.c
+++ b/src/filelock.c
@@ -23,7 +23,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/stat.h>
 #include <signal.h>
 #include <stdio.h>
-#include <setjmp.h>
 #ifdef HAVE_PWD_H
 #include <pwd.h>
diff --git a/src/floatfns.c b/src/floatfns.c
index 8a9a9fd0886..4fe209fcb61 100644
--- a/src/floatfns.c
+++ b/src/floatfns.c
@@ -22,13 +22,14 @@ You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
-/* C89 requires only these math.h functions:
+/* C89 requires only the following math.h functions, and Emacs omits
-   acos, asin, atan, atan2, ceil, cos, cosh, exp, fabs, floor, fmod,
+   the starred functions since we haven't found a use for them:
-   frexp, ldexp, log, log10, modf, pow, sin, sinh, sqrt, tan, tanh.
+   acos, asin, atan, atan2, ceil, cos, *cosh, exp, fabs, floor, fmod,
+   frexp, ldexp, log, log10, *modf, pow, sin, *sinh, sqrt, tan, *tanh.
 */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "syssignal.h"
@@ -42,10 +43,12 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <math.h>
-/* This declaration is omitted on some systems, like Ultrix.  */
+#ifndef isfinite
-#if !defined (HPUX) && defined (HAVE_LOGB) && !defined (logb)
+# define isfinite(x) ((x) - (x) == 0)
-extern double logb (double);
+#endif
-#endif /* not HPUX and HAVE_LOGB and no logb macro */
+#ifndef isnan
+# define isnan(x) ((x) != (x))
+#endif
 /* Extract a Lisp number as a `double', or signal an error.  */
@@ -126,9 +129,6 @@ DEFUN ("tan", Ftan, Stan, 1, 1, 0,
  return make_float (d);
 }
-#undef isnan
-#define isnan(x) ((x) != (x))
 DEFUN ("isnan", Fisnan, Sisnan, 1, 1, 0,
       doc: /* Return non nil iff argument X is a NaN.  */)
  (Lisp_Object x)
@@ -153,6 +153,7 @@ Cause an error if X1 or X2 is not a float.  */)
  return make_float (copysign (f1, f2));
 }
+#endif
 DEFUN ("frexp", Ffrexp, Sfrexp, 1, 1, 0,
       doc: /* Get significand and exponent of a floating point number.
@@ -167,15 +168,9 @@ If X is zero, both parts (SGNFCAND and EXP) are zero.  */)
  (Lisp_Object x)
 {
  double f = XFLOATINT (x);
+  int exponent;
-  if (f == 0.0)
+  double sgnfcand = frexp (f, &exponent);
-    return Fcons (make_float (0.0), make_number (0));
+  return Fcons (make_float (sgnfcand), make_number (exponent));
-  else
-    {
-      int exponent;
-      double sgnfcand = frexp (f, &exponent);
-      return Fcons (make_float (sgnfcand), make_number (exponent));
-    }
 }
 DEFUN ("ldexp", Fldexp, Sldexp, 1, 2, 0,
@@ -187,118 +182,6 @@ Returns the floating point value resulting from multiplying SGNFCAND
  CHECK_NUMBER (exponent);
  return make_float (ldexp (XFLOATINT (sgnfcand), XINT (exponent)));
 }
-#endif
-#if 0 /* Leave these out unless we find there's a reason for them.  */
-DEFUN ("bessel-j0", Fbessel_j0, Sbessel_j0, 1, 1, 0,
-       doc: /* Return the bessel function j0 of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = j0 (d);
-  return make_float (d);
-}
-DEFUN ("bessel-j1", Fbessel_j1, Sbessel_j1, 1, 1, 0,
-       doc: /* Return the bessel function j1 of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = j1 (d);
-  return make_float (d);
-}
-DEFUN ("bessel-jn", Fbessel_jn, Sbessel_jn, 2, 2, 0,
-       doc: /* Return the order N bessel function output jn of ARG.
-The first arg (the order) is truncated to an integer.  */)
-  (Lisp_Object n, Lisp_Object arg)
-{
-  int i1 = extract_float (n);
-  double f2 = extract_float (arg);
-  f2 = jn (i1, f2);
-  return make_float (f2);
-}
-DEFUN ("bessel-y0", Fbessel_y0, Sbessel_y0, 1, 1, 0,
-       doc: /* Return the bessel function y0 of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = y0 (d);
-  return make_float (d);
-}
-DEFUN ("bessel-y1", Fbessel_y1, Sbessel_y1, 1, 1, 0,
-       doc: /* Return the bessel function y1 of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = y1 (d);
-  return make_float (d);
-}
-DEFUN ("bessel-yn", Fbessel_yn, Sbessel_yn, 2, 2, 0,
-       doc: /* Return the order N bessel function output yn of ARG.
-The first arg (the order) is truncated to an integer.  */)
-  (Lisp_Object n, Lisp_Object arg)
-{
-  int i1 = extract_float (n);
-  double f2 = extract_float (arg);
-  f2 = yn (i1, f2);
-  return make_float (f2);
-}
-#endif
-#if 0 /* Leave these out unless we see they are worth having.  */
-DEFUN ("erf", Ferf, Serf, 1, 1, 0,
-       doc: /* Return the mathematical error function of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = erf (d);
-  return make_float (d);
-}
-DEFUN ("erfc", Ferfc, Serfc, 1, 1, 0,
-       doc: /* Return the complementary error function of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = erfc (d);
-  return make_float (d);
-}
-DEFUN ("log-gamma", Flog_gamma, Slog_gamma, 1, 1, 0,
-       doc: /* Return the log gamma of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = lgamma (d);
-  return make_float (d);
-}
-DEFUN ("cube-root", Fcube_root, Scube_root, 1, 1, 0,
-       doc: /* Return the cube root of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-#ifdef HAVE_CBRT
-  d = cbrt (d);
-#else
-  if (d >= 0.0)
-    d = pow (d, 1.0/3.0);
-  else
-    d = -pow (-d, 1.0/3.0);
-#endif
-  return make_float (d);
-}
-#endif
 DEFUN ("exp", Fexp, Sexp, 1, 1, 0,
       doc: /* Return the exponential base e of ARG.  */)
@@ -383,63 +266,6 @@ DEFUN ("sqrt", Fsqrt, Ssqrt, 1, 1, 0,
  return make_float (d);
 }
-#if 0 /* Not clearly worth adding.  */
-DEFUN ("acosh", Facosh, Sacosh, 1, 1, 0,
-       doc: /* Return the inverse hyperbolic cosine of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = acosh (d);
-  return make_float (d);
-}
-DEFUN ("asinh", Fasinh, Sasinh, 1, 1, 0,
-       doc: /* Return the inverse hyperbolic sine of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = asinh (d);
-  return make_float (d);
-}
-DEFUN ("atanh", Fatanh, Satanh, 1, 1, 0,
-       doc: /* Return the inverse hyperbolic tangent of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = atanh (d);
-  return make_float (d);
-}
-DEFUN ("cosh", Fcosh, Scosh, 1, 1, 0,
-       doc: /* Return the hyperbolic cosine of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = cosh (d);
-  return make_float (d);
-}
-DEFUN ("sinh", Fsinh, Ssinh, 1, 1, 0,
-       doc: /* Return the hyperbolic sine of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = sinh (d);
-  return make_float (d);
-}
-DEFUN ("tanh", Ftanh, Stanh, 1, 1, 0,
-       doc: /* Return the hyperbolic tangent of ARG.  */)
-  (Lisp_Object arg)
-{
-  double d = extract_float (arg);
-  d = tanh (d);
-  return make_float (d);
-}
-#endif
 DEFUN ("abs", Fabs, Sabs, 1, 1, 0,
       doc: /* Return the absolute value of ARG.  */)
  (register Lisp_Object arg)
@@ -477,16 +303,15 @@ This is the same as the exponent of a float.  */)
  if (f == 0.0)
    value = MOST_NEGATIVE_FIXNUM;
-  else
+  else if (isfinite (f))
    {
-#ifdef HAVE_LOGB
-      value = logb (f);
-#else
      int ivalue;
      frexp (f, &ivalue);
      value = ivalue - 1;
-#endif
    }
+  else
+    value = MOST_POSITIVE_FIXNUM;
  XSETINT (val, value);
  return val;
 }
@@ -719,27 +544,9 @@ syms_of_floatfns (void)
  defsubr (&Sisnan);
 #ifdef HAVE_COPYSIGN
  defsubr (&Scopysign);
+#endif
  defsubr (&Sfrexp);
  defsubr (&Sldexp);
-#endif
-#if 0
-  defsubr (&Sacosh);
-  defsubr (&Sasinh);
-  defsubr (&Satanh);
-  defsubr (&Scosh);
-  defsubr (&Ssinh);
-  defsubr (&Stanh);
-  defsubr (&Sbessel_y0);
-  defsubr (&Sbessel_y1);
-  defsubr (&Sbessel_yn);
-  defsubr (&Sbessel_j0);
-  defsubr (&Sbessel_j1);
-  defsubr (&Sbessel_jn);
-  defsubr (&Serf);
-  defsubr (&Serfc);
-  defsubr (&Slog_gamma);
-  defsubr (&Scube_root);
-#endif
  defsubr (&Sfceiling);
  defsubr (&Sffloor);
  defsubr (&Sfround);
diff --git a/src/fns.c b/src/fns.c
index 91dc6639150..42c4f817f29 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <unistd.h>
 #include <time.h>
-#include <setjmp.h>
 #include <intprops.h>
diff --git a/src/font.c b/src/font.c
index 49a09bced28..1f22fee88ee 100644
--- a/src/font.c
+++ b/src/font.c
@@ -23,7 +23,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <float.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <c-ctype.h>
@@ -4296,12 +4295,15 @@ to get the correct visual image of character sequences set in the
 header of the glyph-string.
 If the shaping was successful, the value is GSTRING itself or a newly
-created glyph-string.  Otherwise, the value is nil.  */)
+created glyph-string.  Otherwise, the value is nil.
+See the documentation of `composition-get-gstring' for the format of
+GSTRING.  */)
  (Lisp_Object gstring)
 {
  struct font *font;
  Lisp_Object font_object, n, glyph;
-  ptrdiff_t i, j, from, to;
+  ptrdiff_t i, from, to;
  if (! composition_gstring_p (gstring))
    signal_error ("Invalid glyph-string: ", gstring);
@@ -4327,44 +4329,42 @@ created glyph-string.  Otherwise, the value is nil.  */)
  if (XINT (n) < LGSTRING_GLYPH_LEN (gstring))
    LGSTRING_SET_GLYPH (gstring, XINT (n), Qnil);
+  /* Check FROM_IDX and TO_IDX of each GLYPH in GSTRING to assure that
+     GLYPHS covers all characters (except for the last few ones) in
+     GSTRING.  More formally, provided that NCHARS is the number of
+     characters in GSTRING and GLYPHS[i] is the ith glyph, FROM_IDX
+     and TO_IDX of each glyph must satisfy these conditions:
+       GLYPHS[0].FROM_IDX == 0
+       GLYPHS[i].FROM_IDX <= GLYPHS[i].TO_IDX
+       if (GLYPHS[i].FROM_IDX == GLYPHS[i-1].FROM_IDX)
+         ;; GLYPHS[i] and GLYPHS[i-1] belongs to the same grapheme cluster
+         GLYPHS[i].TO_IDX == GLYPHS[i-1].TO_IDX
+       else
+         ;; Be sure to cover all characters.
+         GLYPHS[i].FROM_IDX == GLYPHS[i-1].TO_IDX + 1 */
  glyph = LGSTRING_GLYPH (gstring, 0);
  from = LGLYPH_FROM (glyph);
  to = LGLYPH_TO (glyph);
-  for (i = 1, j = 0; i < LGSTRING_GLYPH_LEN (gstring); i++)
+  if (from != 0 || to < from)
+    goto shaper_error;
+  for (i = 1; i < LGSTRING_GLYPH_LEN (gstring); i++)
    {
-      Lisp_Object this = LGSTRING_GLYPH (gstring, i);
+      glyph = LGSTRING_GLYPH (gstring, i);
+      if (NILP (glyph))
-      if (NILP (this))
        break;
-      if (NILP (LGLYPH_ADJUSTMENT (this)))
+      if (! (LGLYPH_FROM (glyph) <= LGLYPH_TO (glyph)
-        {
+             && (LGLYPH_FROM (glyph) == from
-          if (j < i - 1)
+                 ? LGLYPH_TO (glyph) == to
-            for (; j < i; j++)
+                 : LGLYPH_FROM (glyph) == to + 1)))
-              {
+        goto shaper_error;
-                glyph = LGSTRING_GLYPH (gstring, j);
+      from = LGLYPH_FROM (glyph);
-                LGLYPH_SET_FROM (glyph, from);
+      to = LGLYPH_TO (glyph);
-                LGLYPH_SET_TO (glyph, to);
-              }
-          from = LGLYPH_FROM (this);
-          to = LGLYPH_TO (this);
-          j = i;
-        }
-      else
-        {
-          if (from > LGLYPH_FROM (this))
-            from = LGLYPH_FROM (this);
-          if (to < LGLYPH_TO (this))
-            to = LGLYPH_TO (this);
-        }
    }
-  if (j < i - 1)
-    for (; j < i; j++)
-      {
-        glyph = LGSTRING_GLYPH (gstring, j);
-        LGLYPH_SET_FROM (glyph, from);
-        LGLYPH_SET_TO (glyph, to);
-      }
  return composition_gstring_put_cache (gstring, XINT (n));
+ shaper_error:
+  return Qnil;
 }
 DEFUN ("font-variation-glyphs", Ffont_variation_glyphs, Sfont_variation_glyphs,
diff --git a/src/fontset.c b/src/fontset.c
index 2b955fe6b11..35d4bfb367e 100644
--- a/src/fontset.c
+++ b/src/fontset.c
@@ -26,7 +26,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "blockinput.h"
diff --git a/src/frame.c b/src/frame.c
index 9b12842bf89..6930dac3ce8 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -24,7 +24,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <stdio.h>
 #include <errno.h>
 #include <limits.h>
-#include <setjmp.h>
 #include <c-ctype.h>
@@ -1299,6 +1298,11 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
     structures can still refer to it.  */
  fset_menu_bar_vector (f, Qnil);
+  /* If FRAME's buffer lists contains killed
+     buffers, this helps GC to reclaim them.  */
+  fset_buffer_list (f, Qnil);
+  fset_buried_buffer_list (f, Qnil);
  free_font_driver_list (f);
  xfree (f->namebuf);
  xfree (f->decode_mode_spec_buffer);
diff --git a/src/fringe.c b/src/fringe.c
index 0c2109a0f8e..6e6deeddb08 100644
--- a/src/fringe.c
+++ b/src/fringe.c
@@ -18,7 +18,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "frame.h"
diff --git a/src/ftfont.c b/src/ftfont.c
index a85773a9a21..f07ad6f33c7 100644
--- a/src/ftfont.c
+++ b/src/ftfont.c
@@ -21,8 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <fontconfig/fontconfig.h>
 #include <fontconfig/fcfreetype.h>
diff --git a/src/ftxfont.c b/src/ftxfont.c
index c705ede62c4..466250bd43f 100644
--- a/src/ftxfont.c
+++ b/src/ftxfont.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <X11/Xlib.h>
 #include "lisp.h"
diff --git a/src/gnutls.c b/src/gnutls.c
index a2573f6bd99..1c4693aee32 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -18,7 +18,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <errno.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "process.h"
diff --git a/src/gtkutil.c b/src/gtkutil.c
index 884574e1062..1eb4b2cabdf 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #ifdef USE_GTK
 #include <float.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <c-ctype.h>
diff --git a/src/image.c b/src/image.c
index cf01602050f..8fc1c8637eb 100644
--- a/src/image.c
+++ b/src/image.c
@@ -5514,6 +5514,15 @@ init_png_functions (Lisp_Object libraries)
 #endif /* HAVE_NTGUI */
+/* Possibly inefficient/inexact substitutes for _setjmp and _longjmp.
+   Do not use sys_setjmp, as PNG supports only jmp_buf.  The _longjmp
+   substitute may munge the signal mask, but that should be OK here.
+   MinGW (MS-Windows) uses _setjmp and defines setjmp to _setjmp in
+   the system header setjmp.h; don't mess up that.  */
+#ifndef HAVE__SETJMP
+# define _setjmp(j) setjmp (j)
+# define _longjmp longjmp
+#endif
 #if (PNG_LIBPNG_VER < 10500)
 #define PNG_LONGJMP(ptr) (_longjmp ((ptr)->jmpbuf, 1))
@@ -5591,20 +5600,31 @@ png_read_from_file (png_structp png_ptr, png_bytep data, png_size_t length)
 /* Load PNG image IMG for use on frame F.  Value is non-zero if
   successful.  */
+struct png_load_context
+{
+  /* These are members so that longjmp doesn't munge local variables.  */
+  png_struct *png_ptr;
+  png_info *info_ptr;
+  png_info *end_info;
+  FILE *fp;
+  png_byte *pixels;
+  png_byte **rows;
+};
 static int
-png_load (struct frame *f, struct image *img)
+png_load_body (struct frame *f, struct image *img, struct png_load_context *c)
 {
  Lisp_Object file, specified_file;
  Lisp_Object specified_data;
  int x, y;
  ptrdiff_t i;
  XImagePtr ximg, mask_img = NULL;
-  png_struct *png_ptr = NULL;
+  png_struct *png_ptr;
  png_info *info_ptr = NULL, *end_info = NULL;
-  FILE *volatile fp = NULL;
+  FILE *fp = NULL;
  png_byte sig[8];
-  png_byte * volatile pixels = NULL;
+  png_byte *pixels = NULL;
-  png_byte ** volatile rows = NULL;
+  png_byte **rows = NULL;
  png_uint_32 width, height;
  int bit_depth, color_type, interlace_type;
  png_byte channels;
@@ -5671,24 +5691,26 @@ png_load (struct frame *f, struct image *img)
  png_ptr = fn_png_create_read_struct (PNG_LIBPNG_VER_STRING,
                                       NULL, my_png_error,
                                       my_png_warning);
-  if (!png_ptr)
+  if (png_ptr)
    {
-      if (fp) fclose (fp);
+      info_ptr = fn_png_create_info_struct (png_ptr);
-      return 0;
+      end_info = fn_png_create_info_struct (png_ptr);
    }
-  info_ptr = fn_png_create_info_struct (png_ptr);
+  c->png_ptr = png_ptr;
-  if (!info_ptr)
+  c->info_ptr = info_ptr;
+  c->end_info = end_info;
+  c->fp = fp;
+  c->pixels = pixels;
+  c->rows = rows;
+  if (! (info_ptr && end_info))
    {
-      fn_png_destroy_read_struct (&png_ptr, NULL, NULL);
+      fn_png_destroy_read_struct (&c->png_ptr, &c->info_ptr, &c->end_info);
-      if (fp) fclose (fp);
+      png_ptr = 0;
-      return 0;
    }
+  if (! png_ptr)
-  end_info = fn_png_create_info_struct (png_ptr);
-  if (!end_info)
    {
-      fn_png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
      if (fp) fclose (fp);
      return 0;
    }
@@ -5698,14 +5720,18 @@ png_load (struct frame *f, struct image *img)
  if (_setjmp (PNG_JMPBUF (png_ptr)))
    {
    error:
-      if (png_ptr)
+      if (c->png_ptr)
-        fn_png_destroy_read_struct (&png_ptr, &info_ptr, &end_info);
+        fn_png_destroy_read_struct (&c->png_ptr, &c->info_ptr, &c->end_info);
-      xfree (pixels);
+      xfree (c->pixels);
-      xfree (rows);
+      xfree (c->rows);
-      if (fp) fclose (fp);
+      if (c->fp)
+        fclose (c->fp);
      return 0;
    }
+  /* Silence a bogus diagnostic; see GCC bug 54561.  */
+  IF_LINT (fp = c->fp);
  /* Read image info.  */
  if (!NILP (specified_data))
    fn_png_set_read_fn (png_ptr, (void *) &tbr, png_read_from_memory);
@@ -5821,8 +5847,8 @@ png_load (struct frame *f, struct image *img)
  if (min (PTRDIFF_MAX, SIZE_MAX) / sizeof *rows < height
      || min (PTRDIFF_MAX, SIZE_MAX) / sizeof *pixels / height < row_bytes)
    memory_full (SIZE_MAX);
-  pixels = xmalloc (sizeof *pixels * row_bytes * height);
+  c->pixels = pixels = xmalloc (sizeof *pixels * row_bytes * height);
-  rows = xmalloc (height * sizeof *rows);
+  c->rows = rows = xmalloc (height * sizeof *rows);
  for (i = 0; i < height; ++i)
    rows[i] = pixels + i * row_bytes;
@@ -5832,7 +5858,7 @@ png_load (struct frame *f, struct image *img)
  if (fp)
    {
      fclose (fp);
-      fp = NULL;
+      c->fp = NULL;
    }
  /* Create an image and pixmap serving as mask if the PNG image
@@ -5907,7 +5933,7 @@ png_load (struct frame *f, struct image *img)
 #endif /* COLOR_TABLE_SUPPORT */
  /* Clean up.  */
-  fn_png_destroy_read_struct (&png_ptr, &info_ptr, &end_info);
+  fn_png_destroy_read_struct (&c->png_ptr, &c->info_ptr, &c->end_info);
  xfree (rows);
  xfree (pixels);
@@ -5936,6 +5962,13 @@ png_load (struct frame *f, struct image *img)
  return 1;
 }
+static int
+png_load (struct frame *f, struct image *img)
+{
+  struct png_load_context c;
+  return png_load_body (f, img, &c);
+}
 #else /* HAVE_PNG */
 #ifdef HAVE_NS
@@ -6105,7 +6138,20 @@ jpeg_resync_to_restart_wrapper (j_decompress_ptr cinfo, int desired)
 struct my_jpeg_error_mgr
 {
  struct jpeg_error_mgr pub;
-  jmp_buf setjmp_buffer;
+  sys_jmp_buf setjmp_buffer;
+  /* The remaining members are so that longjmp doesn't munge local
+     variables.  */
+  struct jpeg_decompress_struct cinfo;
+  enum
+    {
+      MY_JPEG_ERROR_EXIT,
+      MY_JPEG_INVALID_IMAGE_SIZE,
+      MY_JPEG_CANNOT_CREATE_X
+    } failure_code;
+#ifdef lint
+  FILE *fp;
+#endif
 };
@@ -6113,7 +6159,8 @@ static _Noreturn void
 my_error_exit (j_common_ptr cinfo)
 {
  struct my_jpeg_error_mgr *mgr = (struct my_jpeg_error_mgr *) cinfo->err;
-  _longjmp (mgr->setjmp_buffer, 1);
+  mgr->failure_code = MY_JPEG_ERROR_EXIT;
+  sys_longjmp (mgr->setjmp_buffer, 1);
 }
@@ -6319,17 +6366,15 @@ jpeg_file_src (j_decompress_ptr cinfo, FILE *fp)
   from the JPEG lib.  */
 static int
-jpeg_load (struct frame *f, struct image *img)
+jpeg_load_body (struct frame *f, struct image *img,
+                struct my_jpeg_error_mgr *mgr)
 {
-  struct jpeg_decompress_struct cinfo;
-  struct my_jpeg_error_mgr mgr;
  Lisp_Object file, specified_file;
  Lisp_Object specified_data;
-  FILE * volatile fp = NULL;
+  FILE *fp = NULL;
  JSAMPARRAY buffer;
  int row_stride, x, y;
  XImagePtr ximg = NULL;
-  int rc;
  unsigned long *colors;
  int width, height;
@@ -6359,26 +6404,37 @@ jpeg_load (struct frame *f, struct image *img)
      return 0;
    }
+  IF_LINT (mgr->fp = fp);
  /* Customize libjpeg's error handling to call my_error_exit when an
     error is detected.  This function will perform a longjmp.  */
-  cinfo.err = fn_jpeg_std_error (&mgr.pub);
+  mgr->cinfo.err = fn_jpeg_std_error (&mgr->pub);
-  mgr.pub.error_exit = my_error_exit;
+  mgr->pub.error_exit = my_error_exit;
+  if (sys_setjmp (mgr->setjmp_buffer))
-  if ((rc = _setjmp (mgr.setjmp_buffer)) != 0)
    {
-      if (rc == 1)
+      switch (mgr->failure_code)
        {
-          /* Called from my_error_exit.  Display a JPEG error.  */
+        case MY_JPEG_ERROR_EXIT:
-          char buf[JMSG_LENGTH_MAX];
+          {
-          cinfo.err->format_message ((j_common_ptr) &cinfo, buf);
+            char buf[JMSG_LENGTH_MAX];
-          image_error ("Error reading JPEG image `%s': %s", img->spec,
+            mgr->cinfo.err->format_message ((j_common_ptr) &mgr->cinfo, buf);
-                       build_string (buf));
+            image_error ("Error reading JPEG image `%s': %s", img->spec,
+                         build_string (buf));
+            break;
+          }
+        case MY_JPEG_INVALID_IMAGE_SIZE:
+          image_error ("Invalid image size (see `max-image-size')", Qnil, Qnil);
+          break;
+        case MY_JPEG_CANNOT_CREATE_X:
+          break;
        }
      /* Close the input file and destroy the JPEG object.  */
      if (fp)
-        fclose ((FILE *) fp);
+        fclose (fp);
-      fn_jpeg_destroy_decompress (&cinfo);
+      fn_jpeg_destroy_decompress (&mgr->cinfo);
      /* If we already have an XImage, free that.  */
      x_destroy_x_image (ximg);
@@ -6388,46 +6444,52 @@ jpeg_load (struct frame *f, struct image *img)
      return 0;
    }
+  /* Silence a bogus diagnostic; see GCC bug 54561.  */
+  IF_LINT (fp = mgr->fp);
  /* Create the JPEG decompression object.  Let it read from fp.
         Read the JPEG image header.  */
-  fn_jpeg_CreateDecompress (&cinfo, JPEG_LIB_VERSION, sizeof (cinfo));
+  fn_jpeg_CreateDecompress (&mgr->cinfo, JPEG_LIB_VERSION, sizeof *&mgr->cinfo);
  if (NILP (specified_data))
-    jpeg_file_src (&cinfo, (FILE *) fp);
+    jpeg_file_src (&mgr->cinfo, fp);
  else
-    jpeg_memory_src (&cinfo, SDATA (specified_data),
+    jpeg_memory_src (&mgr->cinfo, SDATA (specified_data),
                     SBYTES (specified_data));
-  fn_jpeg_read_header (&cinfo, 1);
+  fn_jpeg_read_header (&mgr->cinfo, 1);
  /* Customize decompression so that color quantization will be used.
         Start decompression.  */
-  cinfo.quantize_colors = 1;
+  mgr->cinfo.quantize_colors = 1;
-  fn_jpeg_start_decompress (&cinfo);
+  fn_jpeg_start_decompress (&mgr->cinfo);
-  width = img->width = cinfo.output_width;
+  width = img->width = mgr->cinfo.output_width;
-  height = img->height = cinfo.output_height;
+  height = img->height = mgr->cinfo.output_height;
  if (!check_image_size (f, width, height))
    {
-      image_error ("Invalid image size (see `max-image-size')", Qnil, Qnil);
+      mgr->failure_code = MY_JPEG_INVALID_IMAGE_SIZE;
-      _longjmp (mgr.setjmp_buffer, 2);
+      sys_longjmp (mgr->setjmp_buffer, 1);
    }
  /* Create X image and pixmap.  */
  if (!x_create_x_image_and_pixmap (f, width, height, 0, &ximg, &img->pixmap))
-    _longjmp (mgr.setjmp_buffer, 2);
+    {
+      mgr->failure_code = MY_JPEG_CANNOT_CREATE_X;
+      sys_longjmp (mgr->setjmp_buffer, 1);
+    }
  /* Allocate colors.  When color quantization is used,
-     cinfo.actual_number_of_colors has been set with the number of
+     mgr->cinfo.actual_number_of_colors has been set with the number of
-     colors generated, and cinfo.colormap is a two-dimensional array
+     colors generated, and mgr->cinfo.colormap is a two-dimensional array
-     of color indices in the range 0..cinfo.actual_number_of_colors.
+     of color indices in the range 0..mgr->cinfo.actual_number_of_colors.
     No more than 255 colors will be generated.  */
  {
    int i, ir, ig, ib;
-    if (cinfo.out_color_components > 2)
+    if (mgr->cinfo.out_color_components > 2)
      ir = 0, ig = 1, ib = 2;
-    else if (cinfo.out_color_components > 1)
+    else if (mgr->cinfo.out_color_components > 1)
      ir = 0, ig = 1, ib = 0;
    else
      ir = 0, ig = 0, ib = 0;
@@ -6437,15 +6499,15 @@ jpeg_load (struct frame *f, struct image *img)
       a default color, and we don't have to care about which colors
       can be freed safely, and which can't.  */
    init_color_table ();
-    colors = alloca (cinfo.actual_number_of_colors * sizeof *colors);
+    colors = alloca (mgr->cinfo.actual_number_of_colors * sizeof *colors);
-    for (i = 0; i < cinfo.actual_number_of_colors; ++i)
+    for (i = 0; i < mgr->cinfo.actual_number_of_colors; ++i)
      {
        /* Multiply RGB values with 255 because X expects RGB values
           in the range 0..0xffff.  */
-        int r = cinfo.colormap[ir][i] << 8;
+        int r = mgr->cinfo.colormap[ir][i] << 8;
-        int g = cinfo.colormap[ig][i] << 8;
+        int g = mgr->cinfo.colormap[ig][i] << 8;
-        int b = cinfo.colormap[ib][i] << 8;
+        int b = mgr->cinfo.colormap[ib][i] << 8;
        colors[i] = lookup_rgb_color (f, r, g, b);
      }
@@ -6457,21 +6519,21 @@ jpeg_load (struct frame *f, struct image *img)
  }
  /* Read pixels.  */
-  row_stride = width * cinfo.output_components;
+  row_stride = width * mgr->cinfo.output_components;
-  buffer = cinfo.mem->alloc_sarray ((j_common_ptr) &cinfo, JPOOL_IMAGE,
+  buffer = mgr->cinfo.mem->alloc_sarray ((j_common_ptr) &mgr->cinfo,
-                                    row_stride, 1);
+                                         JPOOL_IMAGE, row_stride, 1);
  for (y = 0; y < height; ++y)
    {
-      fn_jpeg_read_scanlines (&cinfo, buffer, 1);
+      fn_jpeg_read_scanlines (&mgr->cinfo, buffer, 1);
-      for (x = 0; x < cinfo.output_width; ++x)
+      for (x = 0; x < mgr->cinfo.output_width; ++x)
        XPutPixel (ximg, x, y, colors[buffer[0][x]]);
    }
  /* Clean up.  */
-  fn_jpeg_finish_decompress (&cinfo);
+  fn_jpeg_finish_decompress (&mgr->cinfo);
-  fn_jpeg_destroy_decompress (&cinfo);
+  fn_jpeg_destroy_decompress (&mgr->cinfo);
  if (fp)
-    fclose ((FILE *) fp);
+    fclose (fp);
  /* Maybe fill in the background field while we have ximg handy. */
  if (NILP (image_spec_value (img->spec, QCbackground, NULL)))
@@ -6484,6 +6546,13 @@ jpeg_load (struct frame *f, struct image *img)
  return 1;
 }
+static int
+jpeg_load (struct frame *f, struct image *img)
+{
+  struct my_jpeg_error_mgr mgr;
+  return jpeg_load_body (f, img, &mgr);
+}
 #else /* HAVE_JPEG */
 #ifdef HAVE_NS
diff --git a/src/indent.c b/src/indent.c
index c60315a7f6e..053643e6319 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -19,7 +19,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/insdel.c b/src/insdel.c
index b12a390633e..87010cd8251 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -19,7 +19,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include <intprops.h>
@@ -840,8 +839,7 @@ insert_1_both (const char *string,
                             PT + nchars, PT_BYTE + nbytes,
                             before_markers);
-  if (buffer_intervals (current_buffer))
+  offset_intervals (current_buffer, PT, nchars);
-    offset_intervals (current_buffer, PT, nchars);
  if (!inherit && buffer_intervals (current_buffer))
    set_text_properties (make_number (PT), make_number (PT + nchars),
@@ -1153,8 +1151,7 @@ insert_from_buffer_1 (struct buffer *buf,
                             PT_BYTE + outgoing_nbytes,
                             0);
-  if (buffer_intervals (current_buffer))
+  offset_intervals (current_buffer, PT, nchars);
-    offset_intervals (current_buffer, PT, nchars);
  /* Get the intervals for the part of the string we are inserting.  */
  intervals = buffer_intervals (buf);
@@ -1222,8 +1219,7 @@ adjust_after_replace (ptrdiff_t from, ptrdiff_t from_byte,
  else if (len < nchars_del)
    adjust_overlays_for_delete (from, nchars_del - len);
-  if (buffer_intervals (current_buffer))
+  offset_intervals (current_buffer, from, len - nchars_del);
-    offset_intervals (current_buffer, from, len - nchars_del);
  if (from < PT)
    adjust_point (len - nchars_del, len_byte - nbytes_del);
@@ -1394,16 +1390,16 @@ replace_range (ptrdiff_t from, ptrdiff_t to, Lisp_Object new,
  eassert (GPT <= GPT_BYTE);
-  /* Adjust the overlay center as needed.  This must be done after
-     adjusting the markers that bound the overlays.  */
-  adjust_overlays_for_delete (from, nchars_del);
-  adjust_overlays_for_insert (from, inschars);
  /* Adjust markers for the deletion and the insertion.  */
  if (markers)
    adjust_markers_for_replace (from, from_byte, nchars_del, nbytes_del,
                                inschars, outgoing_insbytes);
+  /* Adjust the overlay center as needed.  This must be done after
+     adjusting the markers that bound the overlays.  */
+  adjust_overlays_for_delete (from, nchars_del);
+  adjust_overlays_for_insert (from, inschars);
  offset_intervals (current_buffer, from, inschars - nchars_del);
  /* Get the intervals for the part of the string we are inserting--
@@ -1510,6 +1506,12 @@ replace_range_2 (ptrdiff_t from, ptrdiff_t from_byte,
  eassert (GPT <= GPT_BYTE);
+  /* Adjust markers for the deletion and the insertion.  */
+  if (markers
+      && ! (nchars_del == 1 && inschars == 1 && nbytes_del == insbytes))
+    adjust_markers_for_replace (from, from_byte, nchars_del, nbytes_del,
+                                inschars, insbytes);
  /* Adjust the overlay center as needed.  This must be done after
     adjusting the markers that bound the overlays.  */
  if (nchars_del != inschars)
@@ -1518,12 +1520,6 @@ replace_range_2 (ptrdiff_t from, ptrdiff_t from_byte,
      adjust_overlays_for_delete (from + inschars, nchars_del);
    }
-  /* Adjust markers for the deletion and the insertion.  */
-  if (markers
-      && ! (nchars_del == 1 && inschars == 1 && nbytes_del == insbytes))
-    adjust_markers_for_replace (from, from_byte, nchars_del, nbytes_del,
-                                inschars, insbytes);
  offset_intervals (current_buffer, from, inschars - nchars_del);
  /* Relocate point as if it were a marker.  */
diff --git a/src/intervals.c b/src/intervals.c
index e508f968963..584ee1e923d 100644
--- a/src/intervals.c
+++ b/src/intervals.c
@@ -41,7 +41,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define INTERVALS_INLINE EXTERN_INLINE
-#include <setjmp.h>
 #include <intprops.h>
 #include "lisp.h"
 #include "intervals.h"
@@ -674,8 +673,7 @@ find_interval (register INTERVAL tree, register ptrdiff_t position)
  eassert (relative_position <= TOTAL_LENGTH (tree));
-  if (!handling_signal)
+  tree = balance_possible_root_interval (tree);
-    tree = balance_possible_root_interval (tree);
  while (1)
    {
diff --git a/src/keyboard.c b/src/keyboard.c
index de48b53053b..c80f1d61e77 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -22,7 +22,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define KEYBOARD_INLINE EXTERN_INLINE
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "termchar.h"
 #include "termopts.h"
@@ -56,6 +56,10 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/ioctl.h>
 #endif /* not MSDOS */
+#if defined USABLE_FIONREAD && defined USG5_4
+# include <sys/filio.h>
+#endif
 #include "syssignal.h"
 #include <sys/types.h>
@@ -80,9 +84,7 @@ int interrupt_input_pending;
   pending_atimers separately, to reduce code size.  So, any code that
   changes interrupt_input_pending or pending_atimers should update
   this too.  */
-#ifdef SYNC_INPUT
 int pending_signals;
-#endif
 #define KBD_BUFFER_SIZE 4096
@@ -141,7 +143,7 @@ static ptrdiff_t before_command_echo_length;
 /* For longjmp to where kbd input is being done.  */
-static jmp_buf getcjmp;
+static sys_jmp_buf getcjmp;
 /* True while doing kbd input.  */
 int waiting_for_input;
@@ -388,19 +390,6 @@ int interrupt_input;
 /* Nonzero while interrupts are temporarily deferred during redisplay.  */
 int interrupts_deferred;
-/* Allow configure to inhibit use of FIONREAD.  */
-#ifdef BROKEN_FIONREAD
-#undef FIONREAD
-#endif
-/* We are unable to use interrupts if FIONREAD is not available,
-   so flush SIGIO so we won't try.  */
-#if !defined (FIONREAD)
-#ifdef SIGIO
-#undef SIGIO
-#endif
-#endif
 /* If we support a window system, turn on the code to poll periodically
   to detect C-g.  It isn't actually used when doing interrupt input.  */
 #if defined (HAVE_WINDOW_SYSTEM) && !defined (USE_ASYNC_EVENTS)
@@ -446,12 +435,12 @@ static Lisp_Object modify_event_symbol (ptrdiff_t, int, Lisp_Object,
                                        Lisp_Object *, ptrdiff_t);
 static Lisp_Object make_lispy_switch_frame (Lisp_Object);
 static int help_char_p (Lisp_Object);
-static void save_getcjmp (jmp_buf);
+static void save_getcjmp (sys_jmp_buf);
-static void restore_getcjmp (jmp_buf);
+static void restore_getcjmp (sys_jmp_buf);
 static Lisp_Object apply_modifiers (int, Lisp_Object);
 static void clear_event (struct input_event *);
 static Lisp_Object restore_kboard_configuration (Lisp_Object);
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
 static void deliver_input_available_signal (int signo);
 #endif
 static void handle_interrupt (void);
@@ -2022,17 +2011,9 @@ static struct atimer *poll_timer;
 void
 poll_for_input_1 (void)
 {
-/* Tell ns_read_socket() it is being called asynchronously so it can avoid
-   doing anything dangerous.  */
-#ifdef HAVE_NS
-  ++handling_signal;
-#endif
  if (interrupt_input_blocked == 0
      && !waiting_for_input)
    read_avail_input (0);
-#ifdef HAVE_NS
-  --handling_signal;
-#endif
 }
 /* Timer callback function for poll_timer.  TIMER is equal to
@@ -2043,12 +2024,8 @@ poll_for_input (struct atimer *timer)
 {
  if (poll_suppress_count == 0)
    {
-#ifdef SYNC_INPUT
      interrupt_input_pending = 1;
      pending_signals = 1;
-#else
-      poll_for_input_1 ();
-#endif
    }
 }
@@ -2327,8 +2304,8 @@ read_char (int commandflag, ptrdiff_t nmaps, Lisp_Object *maps,
 {
  volatile Lisp_Object c;
  ptrdiff_t jmpcount;
-  jmp_buf local_getcjmp;
+  sys_jmp_buf local_getcjmp;
-  jmp_buf save_jump;
+  sys_jmp_buf save_jump;
  volatile int key_already_recorded = 0;
  Lisp_Object tem, save;
  volatile Lisp_Object previous_echo_area_message;
@@ -2574,7 +2551,7 @@ read_char (int commandflag, ptrdiff_t nmaps, Lisp_Object *maps,
     it *must not* be in effect when we call redisplay.  */
  jmpcount = SPECPDL_INDEX ();
-  if (_setjmp (local_getcjmp))
+  if (sys_setjmp (local_getcjmp))
    {
      /* Handle quits while reading the keyboard.  */
      /* We must have saved the outer value of getcjmp here,
@@ -3406,13 +3383,13 @@ record_char (Lisp_Object c)
   See read_process_output.  */
 static void
-save_getcjmp (jmp_buf temp)
+save_getcjmp (sys_jmp_buf temp)
 {
  memcpy (temp, getcjmp, sizeof getcjmp);
 }
 static void
-restore_getcjmp (jmp_buf temp)
+restore_getcjmp (sys_jmp_buf temp)
 {
  memcpy (getcjmp, temp, sizeof getcjmp);
 }
@@ -3649,10 +3626,8 @@ kbd_buffer_store_event_hold (register struct input_event *event,
          /* Don't read keyboard input until we have processed kbd_buffer.
             This happens when pasting text longer than KBD_BUFFER_SIZE/2.  */
          hold_keyboard_input ();
-#ifdef SIGIO
          if (!noninteractive)
-            signal (SIGIO, SIG_IGN);
+            ignore_sigio ();
-#endif
          stop_polling ();
        }
 #endif  /* subprocesses */
@@ -3821,14 +3796,14 @@ kbd_buffer_get_event (KBOARD **kbp,
      /* Start reading input again, we have processed enough so we can
         accept new events again.  */
      unhold_keyboard_input ();
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
      if (!noninteractive)
        {
          struct sigaction action;
          emacs_sigaction_init (&action, deliver_input_available_signal);
          sigaction (SIGIO, &action, 0);
        }
-#endif /* SIGIO */
+#endif
      start_polling ();
    }
 #endif  /* subprocesses */
@@ -3870,10 +3845,9 @@ kbd_buffer_get_event (KBOARD **kbp,
      /* One way or another, wait until input is available; then, if
         interrupt handlers have not read it, read it now.  */
-/* Note SIGIO has been undef'd if FIONREAD is missing.  */
+#ifdef USABLE_SIGIO
-#ifdef SIGIO
      gobble_input (0);
-#endif /* SIGIO */
+#endif
      if (kbd_fetch_ptr != kbd_store_ptr)
        break;
 #if defined (HAVE_MOUSE) || defined (HAVE_GPM)
@@ -4352,7 +4326,7 @@ decode_timer (Lisp_Object timer, EMACS_TIME *result)
  if (! NILP (vector[0]))
    return 0;
-  return decode_time_components (vector[1], vector[2], vector[3], vector[4],
+  return decode_time_components (vector[1], vector[2], vector[3], vector[8],
                                 result, 0);
 }
@@ -4554,7 +4528,7 @@ in the same style as (current-time).
 The value when Emacs is not idle is nil.
-NSEC is a multiple of the system clock resolution.  */)
+PSEC is a multiple of the system clock resolution.  */)
  (void)
 {
  if (EMACS_TIME_VALID_P (timer_idleness_start_time))
@@ -6785,7 +6759,7 @@ get_input_pending (int *addr, int flags)
 void
 gobble_input (int expected)
 {
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  if (interrupt_input)
    {
      sigset_t blocked, procmask;
@@ -6840,7 +6814,7 @@ record_asynch_buffer_change (void)
    return;
  /* Make sure no interrupt happens while storing the event.  */
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  if (interrupt_input)
    {
      sigset_t blocked, procmask;
@@ -7066,7 +7040,7 @@ tty_read_avail_input (struct terminal *terminal,
 #endif /* HAVE_GPM */
 /* Determine how many characters we should *try* to read.  */
-#ifdef FIONREAD
+#ifdef USABLE_FIONREAD
  /* Find out how much input is available.  */
  if (ioctl (fileno (tty->input), FIONREAD, &n_to_read) < 0)
    {
@@ -7079,14 +7053,12 @@ tty_read_avail_input (struct terminal *terminal,
    return 0;
  if (n_to_read > sizeof cbuf)
    n_to_read = sizeof cbuf;
-#else /* no FIONREAD */
+#elif defined USG || defined CYGWIN
-#if defined (USG) || defined (CYGWIN)
  /* Read some input if available, but don't wait.  */
  n_to_read = sizeof cbuf;
  fcntl (fileno (tty->input), F_SETFL, O_NDELAY);
 #else
-  you lose;
+# error "Cannot read without possibly delaying"
-#endif
 #endif
 #ifdef subprocesses
@@ -7135,7 +7107,7 @@ tty_read_avail_input (struct terminal *terminal,
 #endif
         );
-#ifndef FIONREAD
+#ifndef USABLE_FIONREAD
 #if defined (USG) || defined (CYGWIN)
  fcntl (fileno (tty->input), F_SETFL, 0);
 #endif /* USG or CYGWIN */
@@ -7206,19 +7178,12 @@ tty_read_avail_input (struct terminal *terminal,
  return nread;
 }
-#if defined SYNC_INPUT || defined SIGIO
 static void
 handle_async_input (void)
 {
  interrupt_input_pending = 0;
-#ifdef SYNC_INPUT
  pending_signals = pending_atimers;
-#endif
-/* Tell ns_read_socket() it is being called asynchronously so it can avoid
-   doing anything dangerous.  */
-#ifdef HAVE_NS
-  ++handling_signal;
-#endif
  while (1)
    {
      int nread;
@@ -7229,13 +7194,8 @@ handle_async_input (void)
      if (nread <= 0)
        break;
    }
-#ifdef HAVE_NS
-  --handling_signal;
-#endif
 }
-#endif /* SYNC_INPUT || SIGIO */
-#ifdef SYNC_INPUT
 void
 process_pending_signals (void)
 {
@@ -7243,25 +7203,17 @@ process_pending_signals (void)
    handle_async_input ();
  do_pending_atimers ();
 }
-#endif
-#ifdef SIGIO   /* for entire page */
+#ifdef USABLE_SIGIO
-/* Note SIGIO has been undef'd if FIONREAD is missing.  */
 static void
 handle_input_available_signal (int sig)
 {
-#ifdef SYNC_INPUT
  interrupt_input_pending = 1;
  pending_signals = 1;
-#endif
  if (input_available_clear_time)
    *input_available_clear_time = make_emacs_time (0, 0);
-#ifndef SYNC_INPUT
-  handle_async_input ();
-#endif
 }
 static void
@@ -7269,7 +7221,7 @@ deliver_input_available_signal (int sig)
 {
  handle_on_main_thread (sig, handle_input_available_signal);
 }
-#endif /* SIGIO */
+#endif /* USABLE_SIGIO */
 /* Send ourselves a SIGIO.
@@ -7280,7 +7232,7 @@ deliver_input_available_signal (int sig)
 void
 reinvoke_input_signal (void)
 {
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  handle_async_input ();
 #endif
 }
@@ -7354,7 +7306,7 @@ handle_user_signal (int sig)
          }
        p->npending++;
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
        if (interrupt_input)
          kill (getpid (), SIGIO);
        else
@@ -11010,7 +10962,7 @@ quit_throw_to_read_char (int from_signal)
    do_switch_frame (make_lispy_switch_frame (internal_last_event_frame),
                     0, 0, Qnil);
-  _longjmp (getcjmp, 1);
+  sys_longjmp (getcjmp, 1);
 }
 DEFUN ("set-input-interrupt-mode", Fset_input_interrupt_mode,
@@ -11023,8 +10975,7 @@ See also `current-input-mode'.  */)
  (Lisp_Object interrupt)
 {
  int new_interrupt_input;
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
-/* Note SIGIO has been undef'd if FIONREAD is missing.  */
 #ifdef HAVE_X_WINDOWS
  if (x_display_list != NULL)
    {
@@ -11035,9 +10986,9 @@ See also `current-input-mode'.  */)
  else
 #endif /* HAVE_X_WINDOWS */
    new_interrupt_input = !NILP (interrupt);
-#else /* not SIGIO */
+#else /* not USABLE_SIGIO */
  new_interrupt_input = 0;
-#endif /* not SIGIO */
+#endif /* not USABLE_SIGIO */
  if (new_interrupt_input != interrupt_input)
    {
@@ -11397,9 +11348,7 @@ init_keyboard (void)
  input_pending = 0;
  interrupt_input_blocked = 0;
  interrupt_input_pending = 0;
-#ifdef SYNC_INPUT
  pending_signals = 0;
-#endif
  /* This means that command_loop_1 won't try to select anything the first
     time through.  */
@@ -11431,15 +11380,14 @@ init_keyboard (void)
      sigaction (SIGQUIT, &action, 0);
 #endif /* not DOS_NT */
    }
-/* Note SIGIO has been undef'd if FIONREAD is missing.  */
+#ifdef USABLE_SIGIO
-#ifdef SIGIO
  if (!noninteractive)
    {
      struct sigaction action;
      emacs_sigaction_init (&action, deliver_input_available_signal);
      sigaction (SIGIO, &action, 0);
    }
-#endif /* SIGIO */
+#endif
 /* Use interrupt input by default, if it works and noninterrupt input
   has deficiencies.  */
diff --git a/src/keymap.c b/src/keymap.c
index d79ff89ed67..66fb52061f9 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -40,7 +40,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "commands.h"
 #include "character.h"
diff --git a/src/lisp.h b/src/lisp.h
index 41fa274a562..37416dc9464 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -20,6 +20,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #ifndef EMACS_LISP_H
 #define EMACS_LISP_H
+#include <setjmp.h>
 #include <stdalign.h>
 #include <stdarg.h>
 #include <stdbool.h>
@@ -1968,7 +1969,25 @@ extern void defvar_kboard (struct Lisp_Kboard_Objfwd *, const char *, int);
    static struct Lisp_Kboard_Objfwd ko_fwd;                    \
    defvar_kboard (&ko_fwd, lname, offsetof (KBOARD, vname ## _)); \
  } while (0)
+/* Save and restore the instruction and environment pointers,
+   without affecting the signal mask.  */
+#ifdef HAVE__SETJMP
+typedef jmp_buf sys_jmp_buf;
+# define sys_setjmp(j) _setjmp (j)
+# define sys_longjmp(j, v) _longjmp (j, v)
+#elif defined HAVE_SIGSETJMP
+typedef sigjmp_buf sys_jmp_buf;
+# define sys_setjmp(j) sigsetjmp (j, 0)
+# define sys_longjmp(j, v) siglongjmp (j, v)
+#else
+/* A platform that uses neither _longjmp nor siglongjmp; assume
+   longjmp does not affect the sigmask.  */
+typedef jmp_buf sys_jmp_buf;
+# define sys_setjmp(j) setjmp (j)
+# define sys_longjmp(j, v) longjmp (j, v)
+#endif
 /* Structure for recording Lisp call stack for backtrace purposes.  */
@@ -2061,7 +2080,7 @@ struct catchtag
  Lisp_Object volatile val;
  struct catchtag *volatile next;
  struct gcpro *gcpro;
-  jmp_buf jmp;
+  sys_jmp_buf jmp;
  struct backtrace *backlist;
  struct handler *handlerlist;
  EMACS_INT lisp_eval_depth;
@@ -2093,22 +2112,16 @@ extern char *stack_bottom;
   If quit-flag is set to `kill-emacs' the SIGINT handler has received
   a request to exit Emacs when it is safe to do.  */
-#ifdef SYNC_INPUT
 extern void process_pending_signals (void);
 extern int pending_signals;
-#define ELSE_PENDING_SIGNALS                            \
-  else if (pending_signals)                             \
-    process_pending_signals ();
-#else  /* not SYNC_INPUT */
-#define ELSE_PENDING_SIGNALS
-#endif  /* not SYNC_INPUT */
 extern void process_quit_flag (void);
 #define QUIT                                            \
  do {                                                  \
    if (!NILP (Vquit_flag) && NILP (Vinhibit_quit))     \
      process_quit_flag ();                             \
-    ELSE_PENDING_SIGNALS                                \
+    else if (pending_signals)                           \
+      process_pending_signals ();                       \
  } while (0)
@@ -2832,8 +2845,6 @@ extern void memory_warnings (void *, void (*warnfun) (const char *));
 /* Defined in alloc.c.  */
 extern void check_pure_size (void);
 extern void allocate_string_data (struct Lisp_String *, EMACS_INT, EMACS_INT);
-extern void reset_malloc_hooks (void);
-extern void uninterrupt_malloc (void);
 extern void malloc_warning (const char *);
 extern _Noreturn void memory_full (size_t);
 extern _Noreturn void buffer_memory_full (ptrdiff_t);
@@ -3029,7 +3040,6 @@ extern Lisp_Object Qand_rest;
 extern Lisp_Object Vautoload_queue;
 extern Lisp_Object Vsignaling_function;
 extern Lisp_Object inhibit_lisp_code;
-extern int handling_signal;
 #if BYTE_MARK_STACK
 extern struct catchtag *catchlist;
 extern struct handler *handlerlist;
diff --git a/src/lread.c b/src/lread.c
index 08a2e856c00..08d5f97292b 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -25,7 +25,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/file.h>
 #include <errno.h>
 #include <limits.h>     /* For CHAR_BIT.  */
-#include <setjmp.h>
 #include <stat-time.h>
 #include "lisp.h"
 #include "intervals.h"
diff --git a/src/macros.c b/src/macros.c
index e81068181b9..a507f12e343 100644
--- a/src/macros.c
+++ b/src/macros.c
@@ -19,7 +19,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "macros.h"
 #include "commands.h"
diff --git a/src/makefile.w32-in b/src/makefile.w32-in
index 7b9c67bf135..24ecb2676da 100644
--- a/src/makefile.w32-in
+++ b/src/makefile.w32-in
@@ -482,7 +482,6 @@ WINDOW_H       = $(SRC)/window.h \
 $(BLD)/alloc.$(O) : \
        $(SRC)/alloc.c \
        $(SRC)/puresize.h \
-        $(SRC)/syssignal.h \
        $(SRC)/w32.h \
        $(NT_INC)/unistd.h \
        $(GNU_LIB)/verify.h \
diff --git a/src/marker.c b/src/marker.c
index bfbb161a71d..0c4e8cb3b55 100644
--- a/src/marker.c
+++ b/src/marker.c
@@ -18,7 +18,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
diff --git a/src/menu.c b/src/menu.c
index bfdc68ca118..7b01d1faefc 100644
--- a/src/menu.c
+++ b/src/menu.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <limits.h> /* for INT_MAX */
 #include "lisp.h"
diff --git a/src/minibuf.c b/src/minibuf.c
index 4ed480a8408..8a1e0ddde86 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <errno.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "commands.h"
diff --git a/src/ns.mk b/src/ns.mk
deleted file mode 100644
index 77fbf5845d9..00000000000
--- a/src/ns.mk
+++ /dev/null
@@ -1,39 +0,0 @@
-### autodeps.mk --- src/Makefile fragment for GNU Emacs
-## Copyright (C) 2008-2012 Free Software Foundation, Inc.
-## This file is part of GNU Emacs.
-## GNU Emacs is free software: you can redistribute it and/or modify
-## it under the terms of the GNU General Public License as published by
-## the Free Software Foundation, either version 3 of the License, or
-## (at your option) any later version.
-## 
-## GNU Emacs is distributed in the hope that it will be useful,
-## but WITHOUT ANY WARRANTY; without even the implied warranty of
-## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-## GNU General Public License for more details.
-## 
-## You should have received a copy of the GNU General Public License
-## along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
-### Commentary:
-## This is inserted in src/Makefile if HAVE_NS. 
-## The only reason this is in a separate file is because $ns_appdir,
-## which appears as a target, is empty on non-NS builds.  Some makes
-## do not like empty targets, even if they are never used.
-${ns_appdir}: ${ns_appsrc}
-        rm -fr ${ns_appdir}
-        ${MKDIR_P} ${ns_appdir}
-        ( cd ${ns_appsrc} ; tar cfh - . ) | ( cd ${ns_appdir} ; umask 022; tar xf - )
-${ns_appbindir}/Emacs: emacs${EXEEXT}
-        ${MKDIR_P} ${ns_appbindir}
-        cp -f emacs${EXEEXT} ${ns_appbindir}/Emacs
-ns-app: ${ns_appdir} ${ns_appbindir}/Emacs
-### ns.mk ends here
diff --git a/src/nsfns.m b/src/nsfns.m
index f73086eeee9..072005d2d3d 100644
--- a/src/nsfns.m
+++ b/src/nsfns.m
@@ -31,7 +31,6 @@ GNUstep port and post-20 update by Adrian Robert (arobert@cogsci.ucsd.edu)
 #include <config.h>
 #include <math.h>
-#include <setjmp.h>
 #include <c-strcase.h>
 #include "lisp.h"
@@ -1797,19 +1796,6 @@ terminate Emacs if we can't open the connection.
               SSDATA (display));
    }
-  /* Register our external input/output types, used for determining
-     applicable services and also drag/drop eligibility. */
-  ns_send_types = [[NSArray arrayWithObjects: NSStringPboardType, nil] retain];
-  ns_return_types = [[NSArray arrayWithObjects: NSStringPboardType, nil]
-                      retain];
-  ns_drag_types = [[NSArray arrayWithObjects:
-                            NSStringPboardType,
-                            NSTabularTextPboardType,
-                            NSFilenamesPboardType,
-                            NSURLPboardType,
-                            NSColorPboardType,
-                            NSFontPboardType, nil] retain];
  return Qnil;
 }
diff --git a/src/nsfont.m b/src/nsfont.m
index 1c9976ec6cc..eba1eb04765 100644
--- a/src/nsfont.m
+++ b/src/nsfont.m
@@ -23,7 +23,6 @@ Author: Adrian Robert (arobert@cogsci.ucsd.edu)
 /* This should be the first include, as it may set up #defines affecting
   interpretation of even the system includes. */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "dispextern.h"
diff --git a/src/nsimage.m b/src/nsimage.m
index 8a8a3ddaae4..668664c7a20 100644
--- a/src/nsimage.m
+++ b/src/nsimage.m
@@ -28,7 +28,6 @@ GNUstep port and post-20 update by Adrian Robert (arobert@cogsci.ucsd.edu)
 /* This should be the first include, as it may set up #defines affecting
   interpretation of even the system includes. */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "dispextern.h"
diff --git a/src/nsmenu.m b/src/nsmenu.m
index d0f3e45e939..907d3eac622 100644
--- a/src/nsmenu.m
+++ b/src/nsmenu.m
@@ -24,7 +24,6 @@ Carbon version by Yamamoto Mitsuharu. */
 /* This should be the first include, as it may set up #defines affecting
   interpretation of even the system includes. */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "window.h"
@@ -589,10 +588,7 @@ extern NSString *NSMenuDidBeginTrackingNotification;
     From 10.6 on, we could also use -[NSMenu propertiesToUpdate]: In the
     key press case, NSMenuPropertyItemImage (e.g.) won't be set.
  */
-  if (trackingMenu == 0
+  if (trackingMenu == 0)
-      /* Also, don't try this if from an event picked up asynchronously,
-         as lots of lisp evaluation happens in ns_update_menubar. */
-      || handling_signal != 0)
    return;
 /*fprintf (stderr, "Updating menu '%s'\n", [[self title] UTF8String]); NSLog (@"%@\n", event); */
  ns_update_menubar (frame, 1, self);
diff --git a/src/nsselect.m b/src/nsselect.m
index e0bbfe58636..95bc1a95957 100644
--- a/src/nsselect.m
+++ b/src/nsselect.m
@@ -28,7 +28,6 @@ GNUstep port and post-20 update by Adrian Robert (arobert@cogsci.ucsd.edu)
 /* This should be the first include, as it may set up #defines affecting
   interpretation of even the system includes. */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "nsterm.h"
diff --git a/src/print.c b/src/print.c
index 5643ff06774..6ae33ee23ef 100644
--- a/src/print.c
+++ b/src/print.c
@@ -21,7 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
diff --git a/src/process.c b/src/process.c
index f80b5e80c76..c654369627d 100644
--- a/src/process.c
+++ b/src/process.c
@@ -25,12 +25,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <stdio.h>
 #include <errno.h>
-#include <setjmp.h>
 #include <sys/types.h>          /* Some typedefs are used in sys/file.h.  */
 #include <sys/file.h>
 #include <sys/stat.h>
-#include <setjmp.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -75,6 +72,11 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <bsdtty.h>
 #endif
+#ifdef USG5_4
+# include <sys/stream.h>
+# include <sys/stropts.h>
+#endif
 #ifdef HAVE_RES_INIT
 #include <netinet/in.h>
 #include <arpa/nameser.h>
@@ -212,17 +214,13 @@ static EMACS_INT update_tick;
   "non-destructive" select.  So we require either native select,
   or emulation of select using FIONREAD.  */
-#ifdef BROKEN_DATAGRAM_SOCKETS
+#ifndef BROKEN_DATAGRAM_SOCKETS
-#undef DATAGRAM_SOCKETS
+# if defined HAVE_SELECT || defined USABLE_FIONREAD
-#else
+#  if defined HAVE_SENDTO && defined HAVE_RECVFROM && defined EMSGSIZE
-#ifndef DATAGRAM_SOCKETS
+#   define DATAGRAM_SOCKETS
-#if defined (HAVE_SELECT) || defined (FIONREAD)
+#  endif
-#if defined (HAVE_SENDTO) && defined (HAVE_RECVFROM) && defined (EMSGSIZE)
+# endif
-#define DATAGRAM_SOCKETS
+#endif
-#endif /* HAVE_SENDTO && HAVE_RECVFROM && EMSGSIZE */
-#endif /* HAVE_SELECT || FIONREAD */
-#endif /* DATAGRAM_SOCKETS */
-#endif /* BROKEN_DATAGRAM_SOCKETS */
 #if defined HAVE_LOCAL_SOCKETS && defined DATAGRAM_SOCKETS
 # define HAVE_SEQPACKET
@@ -251,7 +249,7 @@ static int process_output_skip;
 #endif
 static void create_process (Lisp_Object, char **, Lisp_Object);
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
 static int keyboard_bit_set (SELECT_TYPE *);
 #endif
 static void deactivate_process (Lisp_Object);
@@ -1611,14 +1609,10 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
 #if !defined (WINDOWSNT) && defined (FD_CLOEXEC)
  int wait_child_setup[2];
 #endif
+#ifdef SIGCHLD
  sigset_t blocked, procmask;
-  struct sigaction sigint_action;
-  struct sigaction sigquit_action;
-  struct sigaction sigpipe_action;
-#ifdef AIX
-  struct sigaction sighup_action;
 #endif
-  /* Use volatile to protect variables from being clobbered by longjmp.  */
+  /* Use volatile to protect variables from being clobbered by vfork.  */
  volatile int forkin, forkout;
  volatile int pty_flag = 0;
@@ -1710,25 +1704,13 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
  XPROCESS (process)->pty_flag = pty_flag;
  pset_status (XPROCESS (process), Qrun);
+#ifdef SIGCHLD
  /* Delay interrupts until we have a chance to store
     the new fork's pid in its process structure */
  sigemptyset (&blocked);
-#ifdef SIGCHLD
  sigaddset (&blocked, SIGCHLD);
-#endif
-#ifdef HAVE_WORKING_VFORK
-  /* On many hosts (e.g. Solaris 2.4), if a vforked child calls `signal',
-     this sets the parent's signal handlers as well as the child's.
-     So delay all interrupts whose handlers the child might munge,
-     and record the current handlers so they can be restored later.  */
-  sigaddset (&blocked, SIGINT );  sigaction (SIGINT , 0, &sigint_action );
-  sigaddset (&blocked, SIGQUIT);  sigaction (SIGQUIT, 0, &sigquit_action);
-  sigaddset (&blocked, SIGPIPE);  sigaction (SIGPIPE, 0, &sigpipe_action);
-#ifdef AIX
-  sigaddset (&blocked, SIGHUP );  sigaction (SIGHUP , 0, &sighup_action );
-#endif
-#endif /* HAVE_WORKING_VFORK */
  pthread_sigmask (SIG_BLOCK, &blocked, &procmask);
+#endif
  FD_SET (inchannel, &input_wait_mask);
  FD_SET (inchannel, &non_keyboard_wait_mask);
@@ -1881,8 +1863,10 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
           in the child.  */
        signal (SIGPIPE, SIG_DFL);
+#ifdef SIGCHLD
        /* Stop blocking signals in the child.  */
        pthread_sigmask (SIG_SETMASK, &procmask, 0);
+#endif
        if (pty_flag)
          child_setup_tty (xforkout);
@@ -1961,19 +1945,10 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
 #endif
    }
-  /* Restore the signal state whether vfork succeeded or not.
+#ifdef SIGCHLD
-     (We will signal an error, below, if it failed.)  */
-#ifdef HAVE_WORKING_VFORK
-  /* Restore the parent's signal handlers.  */
-  sigaction (SIGINT, &sigint_action, 0);
-  sigaction (SIGQUIT, &sigquit_action, 0);
-  sigaction (SIGPIPE, &sigpipe_action, 0);
-#ifdef AIX
-  sigaction (SIGHUP, &sighup_action, 0);
-#endif
-#endif /* HAVE_WORKING_VFORK */
  /* Stop blocking signals in the parent.  */
  pthread_sigmask (SIG_SETMASK, &procmask, 0);
+#endif
  /* Now generate the error if vfork failed.  */
  if (pid < 0)
@@ -4397,10 +4372,8 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
         Otherwise, do pending quit if requested.  */
      if (read_kbd >= 0)
        QUIT;
-#ifdef SYNC_INPUT
      else
        process_pending_signals ();
-#endif
      /* Exit now if the cell we're waiting for became non-nil.  */
      if (! NILP (wait_for_cell) && ! NILP (XCAR (wait_for_cell)))
@@ -4836,7 +4809,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
      if (! NILP (wait_for_cell) && ! NILP (XCAR (wait_for_cell)))
        break;
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
      /* If we think we have keyboard input waiting, but didn't get SIGIO,
         go read it.  This can happen with X on BSD after logging out.
         In that case, there really is no input and no SIGIO,
@@ -5420,7 +5393,7 @@ read_process_output (Lisp_Object proc, register int channel)
 /* Sending data to subprocess */
-static jmp_buf send_process_frame;
+static sys_jmp_buf send_process_frame;
 static Lisp_Object process_sent_to;
 static _Noreturn void
@@ -5430,7 +5403,7 @@ handle_pipe_signal (int sig)
  sigemptyset (&unblocked);
  sigaddset (&unblocked, SIGPIPE);
  pthread_sigmask (SIG_UNBLOCK, &unblocked, 0);
-  _longjmp (send_process_frame, 1);
+  sys_longjmp (send_process_frame, 1);
 }
 static void
@@ -5639,7 +5612,7 @@ send_process (volatile Lisp_Object proc, const char *volatile buf,
  /* 2000-09-21: Emacs 20.7, sparc-sun-solaris-2.6, GCC 2.95.2,
     CFLAGS="-g -O": The value of the parameter `proc' is clobbered
     when returning with longjmp despite being declared volatile.  */
-  if (!_setjmp (send_process_frame))
+  if (!sys_setjmp (send_process_frame))
    {
      p = XPROCESS (proc);  /* Repair any setjmp clobbering.  */
      process_sent_to = proc;
@@ -6853,7 +6826,7 @@ delete_gpm_wait_descriptor (int desc)
 # endif
-# ifdef SIGIO
+# ifdef USABLE_SIGIO
 /* Return nonzero if *MASK has a bit set
   that corresponds to one of the keyboard input descriptors.  */
diff --git a/src/ralloc.c b/src/ralloc.c
index 74834333aa3..9a4b1ada229 100644
--- a/src/ralloc.c
+++ b/src/ralloc.c
@@ -25,7 +25,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #ifdef emacs
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"               /* Needed for VALBITS.  */
 #include "blockinput.h"
@@ -1204,9 +1204,15 @@ r_alloc_init (void)
  UNBLOCK_INPUT;
 #else
 #ifndef SYSTEM_MALLOC
-  /* Give GNU malloc's morecore some hysteresis
+  /* Give GNU malloc's morecore some hysteresis so that we move all
-     so that we move all the relocatable blocks much less often.  */
+     the relocatable blocks much less often.  The number used to be
-  __malloc_extra_blocks = 64;
+     64, but alloc.c would override that with 32 in code that was
+     removed when SYNC_INPUT became the only input handling mode.
+     That code was conditioned on !DOUG_LEA_MALLOC, so the call to
+     mallopt above is left unchanged.  (Actually, I think there's no
+     system nowadays that uses DOUG_LEA_MALLOC and also uses
+     REL_ALLOC.)  */
+  __malloc_extra_blocks = 32;
 #endif
 #endif
diff --git a/src/regex.c b/src/regex.c
index 472ef727979..17562043df1 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -126,7 +126,6 @@
   that make sense only in Emacs. */
 #ifdef emacs
-# include <setjmp.h>
 # include "lisp.h"
 # include "character.h"
 # include "buffer.h"
@@ -1832,9 +1831,9 @@ typedef struct
 /* The next available element.  */
 #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])
-/* Explicit quit checking is only used on NTemacs and whenever we
+/* Explicit quit checking is needed for Emacs, which uses polling to
-   use polling to process input events.  */
+   process input events.  */
-#if defined emacs && (defined WINDOWSNT || defined SYNC_INPUT) && defined QUIT
+#ifdef emacs
 extern int immediate_quit;
 # define IMMEDIATE_QUIT_CHECK                   \
    do {                                        \
diff --git a/src/region-cache.c b/src/region-cache.c
index c3eb087aade..832f4bfd214 100644
--- a/src/region-cache.c
+++ b/src/region-cache.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/scroll.c b/src/scroll.c
index 79dd464b29e..71ce43b2e48 100644
--- a/src/scroll.c
+++ b/src/scroll.c
@@ -21,7 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "termchar.h"
 #include "dispextern.h"
diff --git a/src/search.c b/src/search.c
index 72bd5605709..1735ade5d8a 100644
--- a/src/search.c
+++ b/src/search.c
@@ -20,7 +20,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "syntax.h"
 #include "category.h"
@@ -674,7 +674,7 @@ scan_buffer (register int target, ptrdiff_t start, ptrdiff_t end,
           obstacle --- the last character the dumb search loop should
           examine.  */
        ptrdiff_t ceiling_byte = CHAR_TO_BYTE (end) - 1;
-        ptrdiff_t start_byte = CHAR_TO_BYTE (start);
+        ptrdiff_t start_byte;
        ptrdiff_t tem;
        /* If we're looking for a newline, consult the newline cache
@@ -684,18 +684,22 @@ scan_buffer (register int target, ptrdiff_t start, ptrdiff_t end,
            ptrdiff_t next_change;
            immediate_quit = 0;
            while (region_cache_forward
-                   (current_buffer, newline_cache, start_byte, &next_change))
+                   (current_buffer, newline_cache, start, &next_change))
-              start_byte = next_change;
+              start = next_change;
            immediate_quit = allow_quit;
+            start_byte = CHAR_TO_BYTE (start);
            /* START should never be after END.  */
            if (start_byte > ceiling_byte)
              start_byte = ceiling_byte;
            /* Now the text after start is an unknown region, and
               next_change is the position of the next known region. */
-            ceiling_byte = min (next_change - 1, ceiling_byte);
+            ceiling_byte = min (CHAR_TO_BYTE (next_change) - 1, ceiling_byte);
          }
+        else
+          start_byte = CHAR_TO_BYTE (start);
        /* The dumb loop can only scan text stored in contiguous
           bytes. BUFFER_CEILING_OF returns the last character
@@ -747,7 +751,7 @@ scan_buffer (register int target, ptrdiff_t start, ptrdiff_t end,
      {
        /* The last character to check before the next obstacle.  */
        ptrdiff_t ceiling_byte = CHAR_TO_BYTE (end);
-        ptrdiff_t start_byte = CHAR_TO_BYTE (start);
+        ptrdiff_t start_byte;
        ptrdiff_t tem;
        /* Consult the newline cache, if appropriate.  */
@@ -756,18 +760,22 @@ scan_buffer (register int target, ptrdiff_t start, ptrdiff_t end,
            ptrdiff_t next_change;
            immediate_quit = 0;
            while (region_cache_backward
-                   (current_buffer, newline_cache, start_byte, &next_change))
+                   (current_buffer, newline_cache, start, &next_change))
-              start_byte = next_change;
+              start = next_change;
            immediate_quit = allow_quit;
+            start_byte = CHAR_TO_BYTE (start);
            /* Start should never be at or before end.  */
            if (start_byte <= ceiling_byte)
              start_byte = ceiling_byte + 1;
            /* Now the text before start is an unknown region, and
               next_change is the position of the next known region. */
-            ceiling_byte = max (next_change, ceiling_byte);
+            ceiling_byte = max (CHAR_TO_BYTE (next_change), ceiling_byte);
          }
+        else
+          start_byte = CHAR_TO_BYTE (start);
        /* Stop scanning before the gap.  */
        tem = BUFFER_FLOOR_OF (start_byte - 1);
diff --git a/src/sheap.c b/src/sheap.c
index 3ae14b5daec..f6022ea3ce7 100644
--- a/src/sheap.c
+++ b/src/sheap.c
@@ -20,7 +20,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include <unistd.h>
@@ -93,4 +93,3 @@ report_sheap_usage (int die_if_pure_storage_exceeded)
           bss_sbrk_ptr - bss_sbrk_buffer, STATIC_HEAP_SIZE);
  message ("%s", buf);
 }
diff --git a/src/sound.c b/src/sound.c
index 5729d704b6a..0ee85312fd3 100644
--- a/src/sound.c
+++ b/src/sound.c
@@ -44,7 +44,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <unistd.h>
 #include <sys/types.h>
 #include <errno.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "dispextern.h"
 #include "atimer.h"
@@ -314,7 +314,7 @@ sound_perror (const char *msg)
  int saved_errno = errno;
  turn_on_atimers (1);
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  {
    sigset_t unblocked;
    sigemptyset (&unblocked);
@@ -732,7 +732,7 @@ static void
 vox_configure (struct sound_device *sd)
 {
  int val;
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  sigset_t blocked;
 #endif
@@ -742,7 +742,7 @@ vox_configure (struct sound_device *sd)
     interrupted by a signal.  Block the ones we know to cause
     troubles.  */
  turn_on_atimers (0);
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  sigemptyset (&blocked);
  sigaddset (&blocked, SIGIO);
  pthread_sigmask (SIG_BLOCK, &blocked, 0);
@@ -778,7 +778,7 @@ vox_configure (struct sound_device *sd)
    }
  turn_on_atimers (1);
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  pthread_sigmask (SIG_UNBLOCK, &blocked, 0);
 #endif
 }
@@ -794,7 +794,7 @@ vox_close (struct sound_device *sd)
      /* On GNU/Linux, it seems that the device driver doesn't like to
         be interrupted by a signal.  Block the ones we know to cause
         troubles.  */
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
      sigset_t blocked;
      sigemptyset (&blocked);
      sigaddset (&blocked, SIGIO);
@@ -806,7 +806,7 @@ vox_close (struct sound_device *sd)
      ioctl (sd->fd, SNDCTL_DSP_SYNC, NULL);
      turn_on_atimers (1);
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
      pthread_sigmask (SIG_UNBLOCK, &blocked, 0);
 #endif
diff --git a/src/syntax.c b/src/syntax.c
index fdd9353bb87..91ef4e66663 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -21,7 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <sys/types.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "commands.h"
 #include "character.h"
diff --git a/src/sysdep.c b/src/sysdep.c
index 0f16d1a7645..dbfd9efc7d4 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -23,7 +23,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <execinfo.h>
 #include <stdio.h>
-#include <setjmp.h>
 #ifdef HAVE_PWD_H
 #include <pwd.h>
 #include <grp.h>
@@ -107,9 +106,6 @@ extern char *getwd (char *);
 static int emacs_get_tty (int, struct emacs_tty *);
 static int emacs_set_tty (int, struct emacs_tty *, int);
-#if defined TIOCNOTTY || defined USG5 || defined CYGWIN
-static _Noreturn void croak (char *);
-#endif
 /* ULLONG_MAX is missing on Red Hat Linux 7.3; see Bug#11781.  */
 #ifndef ULLONG_MAX
@@ -513,7 +509,7 @@ sys_subshell (void)
  saved_handlers[0].code = SIGINT;
  saved_handlers[1].code = SIGQUIT;
  saved_handlers[2].code = SIGTERM;
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
  saved_handlers[3].code = SIGIO;
  saved_handlers[4].code = 0;
 #else
@@ -642,121 +638,75 @@ restore_signal_handlers (struct save_signal *saved_handlers)
    }
 }
-#ifndef SIGIO
+#ifdef USABLE_SIGIO
-/* If SIGIO is broken, don't do anything. */
-void
-init_sigio (int fd)
-{
-}
-static void
-reset_sigio (int fd)
-{
-}
-void
-request_sigio (void)
-{
-}
-void
-unrequest_sigio (void)
-{
-}
-#else
-#ifdef F_SETFL
 static int old_fcntl_flags[MAXDESC];
+#endif
 void
 init_sigio (int fd)
 {
-#ifdef FASYNC
+#ifdef USABLE_SIGIO
  old_fcntl_flags[fd] = fcntl (fd, F_GETFL, 0) & ~FASYNC;
  fcntl (fd, F_SETFL, old_fcntl_flags[fd] | FASYNC);
-#endif
  interrupts_deferred = 0;
+#endif
 }
 static void
 reset_sigio (int fd)
 {
-#ifdef FASYNC
+#ifdef USABLE_SIGIO
  fcntl (fd, F_SETFL, old_fcntl_flags[fd]);
 #endif
 }
-#ifdef FASYNC           /* F_SETFL does not imply existence of FASYNC */
-/* XXX Uhm, FASYNC is not used anymore here. */
-/* XXX Yeah, but you need it for SIGIO, don't you? */
 void
 request_sigio (void)
 {
+#ifdef USABLE_SIGIO
  sigset_t unblocked;
  if (noninteractive)
    return;
  sigemptyset (&unblocked);
-#ifdef SIGWINCH
+# ifdef SIGWINCH
  sigaddset (&unblocked, SIGWINCH);
-#endif
+# endif
  sigaddset (&unblocked, SIGIO);
  pthread_sigmask (SIG_UNBLOCK, &unblocked, 0);
  interrupts_deferred = 0;
+#endif
 }
 void
 unrequest_sigio (void)
 {
+#ifdef USABLE_SIGIO
  sigset_t blocked;
  if (noninteractive)
    return;
-#if 0 /* XXX What's wrong with blocking SIGIO under X?  */
-  if (x_display_list)
-    return;
-#endif
  sigemptyset (&blocked);
-#ifdef SIGWINCH
+# ifdef SIGWINCH
  sigaddset (&blocked, SIGWINCH);
-#endif
+# endif
  sigaddset (&blocked, SIGIO);
  pthread_sigmask (SIG_BLOCK, &blocked, 0);
  interrupts_deferred = 1;
-}
+#endif
-#else /* no FASYNC */
-#ifndef MSDOS
-void
-request_sigio (void)
-{
-  if (noninteractive || read_socket_hook)
-    return;
-  croak ("request_sigio");
 }
 void
-unrequest_sigio (void)
+ignore_sigio (void)
 {
-  if (noninteractive || read_socket_hook)
+#ifdef USABLE_SIGIO
-    return;
+  signal (SIGIO, SIG_IGN);
+#endif
-  croak ("unrequest_sigio");
 }
-#endif /* MSDOS */
-#endif /* FASYNC */
-#endif /* F_SETFL */
-#endif /* SIGIO */
 /* Getting and setting emacs_tty structures.  */
@@ -1497,27 +1447,21 @@ emacs_sigaction_init (struct sigaction *action, signal_handler_t handler)
  action->sa_handler = handler;
  action->sa_flags = 0;
 #if defined (SA_RESTART)
-  /* Emacs mostly works better with restartable system services. If this
+  /* SA_RESTART causes interruptible functions with timeouts (e.g.,
-     flag exists, we probably want to turn it on here.
+     'select') to reset their timeout on some platforms (e.g.,
-     However, on some systems (only hpux11 at present) this resets the
+     HP-UX 11), which is not what we want.  Also, when Emacs is
-     timeout of `select' which means that `select' never finishes if
+     interactive, we don't want SA_RESTART because we need to poll
-     it keeps getting signals.
-     We define BROKEN_SA_RESTART on those systems.  */
-  /* It's not clear why the comment above says "mostly works better".  --Stef
-     When SYNC_INPUT is set, we don't want SA_RESTART because we need to poll
     for pending input so we need long-running syscalls to be interrupted
     after a signal that sets the interrupt_input_pending flag.  */
  /* Non-interactive keyboard input goes through stdio, where we always
     want restartable system calls.  */
-# if defined (BROKEN_SA_RESTART) || defined (SYNC_INPUT)
  if (noninteractive)
-# endif
    action->sa_flags = SA_RESTART;
 #endif
 }
 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
-pthread_t main_thread;
+static pthread_t main_thread;
 #endif
 /* If we are on the main thread, handle the signal SIG with HANDLER.
@@ -1964,11 +1908,9 @@ emacs_write (int fildes, const char *buf, ptrdiff_t nbyte)
        {
          if (errno == EINTR)
            {
-#ifdef SYNC_INPUT
              /* I originally used `QUIT' but that might causes files to
                 be truncated if you hit C-g in the middle of it.  --Stef  */
              process_pending_signals ();
-#endif
              continue;
            }
          else
@@ -2051,19 +1993,6 @@ getwd (char *pathname)
 }
 #endif /* !defined (HAVE_GETWD) || defined (BROKEN_GETWD) */
-/*
- *      This function will go away as soon as all the stubs fixed. (fnf)
- */
-void
-croak (char *badfunc)
-{
-  printf ("%s not yet implemented\r\n", badfunc);
-  reset_all_sys_modes ();
-  exit (1);
-}
 #endif /* USG */
 /* Directory routines for systems that don't have them. */
diff --git a/src/syssignal.h b/src/syssignal.h
index c5529ae718a..e309e6725b7 100644
--- a/src/syssignal.h
+++ b/src/syssignal.h
@@ -34,27 +34,6 @@ typedef void (*signal_handler_t) (int);
 extern void emacs_sigaction_init (struct sigaction *, signal_handler_t);
-#if ! (defined TIOCNOTTY || defined USG5 || defined CYGWIN)
-_Noreturn void croak (char *);
-#endif
-/* Interrupt input is not used if there is no FIONREAD.  */
-#include <sys/ioctl.h>
-#if defined BROKEN_SIGIO || ! defined FIONREAD || defined BROKEN_FIONREAD
-# undef SIGIO
-#endif
-/* These are only used by AIX  */
-#if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
-#undef SIGPOLL
-#endif
-#if defined (SIGAIO) && defined (BROKEN_SIGAIO)
-#undef SIGAIO
-#endif
-#if defined (SIGPTY) && defined (BROKEN_SIGPTY)
-#undef SIGPTY
-#endif
 #if NSIG < NSIG_MINIMUM
 # undef NSIG
 # define NSIG NSIG_MINIMUM
@@ -85,8 +64,4 @@ _Noreturn void croak (char *);
 char *strsignal (int);
 #endif
-#ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
-extern pthread_t main_thread;
-#endif
 void handle_on_main_thread (int, signal_handler_t);
diff --git a/src/systty.h b/src/systty.h
index b660441a91e..b7f36c6c259 100644
--- a/src/systty.h
+++ b/src/systty.h
@@ -17,10 +17,8 @@ You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* Include the proper files.  */
 #ifndef DOS_NT
-#ifndef NO_TERMIO
-#include <termio.h>
-#endif /* not NO_TERMIO */
 #include <termios.h>
 #include <fcntl.h>
 #endif /* not DOS_NT */
@@ -39,15 +37,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <unistd.h>
-/* Special cases - inhibiting the use of certain features.  */
-/* Allow configure to inhibit use of FIONREAD.  */
-#ifdef BROKEN_FIONREAD
-#undef FIONREAD
-#undef ASYNC
-#endif
 /* Try to establish the correct character to disable terminal functions
   in a system-independent manner.  Note that USG (at least) define
   _POSIX_VDISABLE as 0!  */
diff --git a/src/term.c b/src/term.c
index 0eaf76a13df..f4117d67dec 100644
--- a/src/term.c
+++ b/src/term.c
@@ -25,7 +25,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/file.h>
 #include <sys/time.h>
 #include <unistd.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "termchar.h"
@@ -2944,8 +2943,7 @@ dissociate_if_controlling_tty (int fd)
        emacs_close (fd);
      pthread_sigmask (SIG_UNBLOCK, &blocked, 0);
 #else
-      /* Unknown system. */
+# error "Unknown system."
-      croak ();
 #endif  /* ! TIOCNOTTY */
 #endif  /* ! USG */
    }
diff --git a/src/termcap.c b/src/termcap.c
index d1b05e8df94..e494cd113d9 100644
--- a/src/termcap.c
+++ b/src/termcap.c
@@ -19,7 +19,6 @@ Boston, MA 02110-1301, USA.  */
 /* Emacs config.h may rename various library functions such as malloc.  */
 #include <config.h>
-#include <setjmp.h>
 #include <sys/file.h>
 #include <fcntl.h>
 #include <unistd.h>
diff --git a/src/terminal.c b/src/terminal.c
index c51a18dfa61..719c2a36111 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define TERMHOOKS_INLINE EXTERN_INLINE
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "frame.h"
diff --git a/src/terminfo.c b/src/terminfo.c
index ca2d89a000b..124c452a4a9 100644
--- a/src/terminfo.c
+++ b/src/terminfo.c
@@ -19,7 +19,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include "tparam.h"
-#include <setjmp.h>
 #include "lisp.h"
 /* Define these variables that serve as global parameters to termcap,
diff --git a/src/textprop.c b/src/textprop.c
index 2a9efba1c45..872912ea706 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "intervals.h"
 #include "character.h"
diff --git a/src/tparam.c b/src/tparam.c
index 58a825c90d7..164f61d471b 100644
--- a/src/tparam.c
+++ b/src/tparam.c
@@ -19,7 +19,7 @@ Boston, MA 02110-1301, USA.  */
 /* Emacs config.h may rename various library functions such as malloc.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"               /* for xmalloc */
 #include "tparam.h"
diff --git a/src/undo.c b/src/undo.c
index 9cd1d5f9f67..e878ef4dcf9 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -18,7 +18,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
diff --git a/src/unexaix.c b/src/unexaix.c
index c09156296f7..c01a22a79f6 100644
--- a/src/unexaix.c
+++ b/src/unexaix.c
@@ -89,7 +89,6 @@ static int adjust_lnnoptrs (int, int, const char *);
 static int pagemask;
-#include <setjmp.h>
 #include "lisp.h"
 static void
diff --git a/src/unexcoff.c b/src/unexcoff.c
index e83042a379d..966dd58cb6e 100644
--- a/src/unexcoff.c
+++ b/src/unexcoff.c
@@ -120,7 +120,6 @@ static int pagemask;
 #define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
-#include <setjmp.h>
 #include "lisp.h"
 static void
diff --git a/src/unexcw.c b/src/unexcw.c
index eae534cf4dd..96c4b4a9aec 100644
--- a/src/unexcw.c
+++ b/src/unexcw.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include "unexec.h"
-#include <setjmp.h>
 #include <lisp.h>
 #include <stdio.h>
 #include <fcntl.h>
diff --git a/src/unexsol.c b/src/unexsol.c
index 336f3b4faea..470206d5838 100644
--- a/src/unexsol.c
+++ b/src/unexsol.c
@@ -4,7 +4,6 @@
 #include "unexec.h"
 #include <dlfcn.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/vm-limit.c b/src/vm-limit.c
index cf697b56fdf..8de0acd1bb2 100644
--- a/src/vm-limit.c
+++ b/src/vm-limit.c
@@ -17,7 +17,6 @@ You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include <unistd.h> /* for 'environ', on AIX */
 #include "lisp.h"
 #include "mem-limits.h"
diff --git a/src/w16select.c b/src/w16select.c
index 2026de7421d..a3f6f1fb9ae 100644
--- a/src/w16select.c
+++ b/src/w16select.c
@@ -31,7 +31,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <dpmi.h>
 #include <go32.h>
 #include <sys/farptr.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "dispextern.h" /* frame.h seems to want this */
 #include "frame.h"      /* Need this to get the X window of selected_frame */
diff --git a/src/w32.c b/src/w32.c
index 04f7471577c..bcb0511e2fa 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -33,7 +33,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/utime.h>
 #include <mbstring.h>   /* for _mbspbrk */
 #include <math.h>
-#include <setjmp.h>
 #include <time.h>
 /* must include CRT headers *before* config.h */
diff --git a/src/w32console.c b/src/w32console.c
index 76585851e7f..b22b09af2f2 100644
--- a/src/w32console.c
+++ b/src/w32console.c
@@ -26,7 +26,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <stdio.h>
 #include <windows.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/w32fns.c b/src/w32fns.c
index ec1acbd89d9..be008bb18c8 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -26,7 +26,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <limits.h>
 #include <errno.h>
 #include <math.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "w32term.h"
diff --git a/src/w32font.c b/src/w32font.c
index 8b3a0e4312e..833b7cdfb25 100644
--- a/src/w32font.c
+++ b/src/w32font.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <math.h>
 #include <ctype.h>
 #include <commdlg.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "w32term.h"
diff --git a/src/w32heap.c b/src/w32heap.c
index 26cc9aa0a0f..dc65198f90b 100644
--- a/src/w32heap.c
+++ b/src/w32heap.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "w32heap.h"
 #include "lisp.h"  /* for VALMASK */
diff --git a/src/w32inevt.c b/src/w32inevt.c
index 731dd6715dc..ee07db5335b 100644
--- a/src/w32inevt.c
+++ b/src/w32inevt.c
@@ -25,7 +25,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
 #include <windows.h>
-#include <setjmp.h>
 #ifndef MOUSE_MOVED
 #define MOUSE_MOVED   1
diff --git a/src/w32menu.c b/src/w32menu.c
index d4de73a0de7..fa7db64f147 100644
--- a/src/w32menu.c
+++ b/src/w32menu.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <signal.h>
 #include <stdio.h>
 #include <mbstring.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "keyboard.h"
diff --git a/src/w32proc.c b/src/w32proc.c
index 74427e76a4f..26a0925ad87 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -28,7 +28,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/file.h>
-#include <setjmp.h>
 /* must include CRT headers *before* config.h */
 #include <config.h>
diff --git a/src/w32reg.c b/src/w32reg.c
index 9c727ae5ab7..8a6a3c853b1 100644
--- a/src/w32reg.c
+++ b/src/w32reg.c
@@ -19,7 +19,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* Written by Kevin Gallo */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "w32term.h"
 #include "blockinput.h"
diff --git a/src/w32select.c b/src/w32select.c
index 3fb88d4f17f..11c68c9c617 100644
--- a/src/w32select.c
+++ b/src/w32select.c
@@ -73,7 +73,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 */
 #include <config.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "w32term.h"    /* for all of the w32 includes */
 #include "w32heap.h"    /* os_subtype */
diff --git a/src/w32term.c b/src/w32term.c
index 28c1c593cf6..6244728b264 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <signal.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "blockinput.h"
 #include "w32term.h"
@@ -4163,6 +4162,7 @@ w32_read_socket (struct terminal *terminal, int expected,
  if (interrupt_input_blocked)
    {
      interrupt_input_pending = 1;
+      pending_signals = 1;
      return -1;
    }
diff --git a/src/w32uniscribe.c b/src/w32uniscribe.c
index cf99d14dc77..5d160b9d42f 100644
--- a/src/w32uniscribe.c
+++ b/src/w32uniscribe.c
@@ -27,7 +27,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define _WIN32_WINNT 0x500
 #include <windows.h>
 #include <usp10.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "w32term.h"
diff --git a/src/w32xfns.c b/src/w32xfns.c
index 820dbcc76c6..33f40fc7c01 100644
--- a/src/w32xfns.c
+++ b/src/w32xfns.c
@@ -19,7 +19,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <signal.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "keyboard.h"
 #include "frame.h"
diff --git a/src/widget.c b/src/widget.c
index 0100acc8143..fd5ad167125 100644
--- a/src/widget.c
+++ b/src/widget.c
@@ -30,7 +30,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "xterm.h"
diff --git a/src/window.c b/src/window.c
index cf296a707e3..2589596ccfd 100644
--- a/src/window.c
+++ b/src/window.c
@@ -23,7 +23,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define WINDOW_INLINE EXTERN_INLINE
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
@@ -1857,23 +1856,23 @@ return value is a list of elements of the form (PARAMETER . VALUE).  */)
 DEFUN ("window-parameter", Fwindow_parameter, Swindow_parameter,
       2, 2, 0,
       doc:  /* Return WINDOW's value for PARAMETER.
-WINDOW must be a valid window and defaults to the selected one.  */)
+WINDOW can be any window and defaults to the selected one.  */)
  (Lisp_Object window, Lisp_Object parameter)
 {
  Lisp_Object result;
-  result = Fassq (parameter, decode_valid_window (window)->window_parameters);
+  result = Fassq (parameter, decode_any_window (window)->window_parameters);
  return CDR_SAFE (result);
 }
 DEFUN ("set-window-parameter", Fset_window_parameter,
       Sset_window_parameter, 3, 3, 0,
       doc: /* Set WINDOW's value of PARAMETER to VALUE.
-WINDOW must be a valid window and defaults to the selected one.
+WINDOW can be any window and defaults to the selected one.
 Return VALUE.  */)
  (Lisp_Object window, Lisp_Object parameter, Lisp_Object value)
 {
-  register struct window *w = decode_valid_window (window);
+  register struct window *w = decode_any_window (window);
  Lisp_Object old_alist_elt;
  old_alist_elt = Fassq (parameter, w->window_parameters);
@@ -2659,7 +2658,7 @@ window_loop (enum window_loop type, Lisp_Object obj, int mini, Lisp_Object frame
            /* Check for a window that has a killed buffer.  */
          case CHECK_ALL_WINDOWS:
            if (! NILP (w->buffer)
-                && NILP (BVAR (XBUFFER (w->buffer), name)))
+                && !BUFFER_LIVE_P (XBUFFER (w->buffer)))
              emacs_abort ();
            break;
@@ -3264,7 +3263,7 @@ This function runs `window-scroll-functions' before running
  XSETWINDOW (window, w);
  buffer = Fget_buffer (buffer_or_name);
  CHECK_BUFFER (buffer);
-  if (NILP (BVAR (XBUFFER (buffer), name)))
+  if (!BUFFER_LIVE_P (XBUFFER (buffer)))
    error ("Attempt to display deleted buffer");
  tem = w->buffer;
@@ -3329,7 +3328,7 @@ displaying that buffer.  */)
  if (STRINGP (object))
    object = Fget_buffer (object);
-  if (BUFFERP (object) && !NILP (BVAR (XBUFFER (object), name)))
+  if (BUFFERP (object) && BUFFER_LIVE_P (XBUFFER (object)))
    {
      /* Walk all windows looking for buffer, and force update
         of each of those windows.  */
@@ -5543,7 +5542,7 @@ the return value is nil.  Otherwise the value is t.  */)
  saved_windows = XVECTOR (data->saved_windows);
  new_current_buffer = data->current_buffer;
-  if (NILP (BVAR (XBUFFER (new_current_buffer), name)))
+  if (!BUFFER_LIVE_P (XBUFFER (new_current_buffer)))
    new_current_buffer = Qnil;
  else
    {
@@ -5618,7 +5617,7 @@ the return value is nil.  Otherwise the value is t.  */)
          w = XWINDOW (window);
          if (!NILP (w->buffer)
              && !EQ (w->buffer, p->buffer)
-              && !NILP (BVAR (XBUFFER (p->buffer), name)))
+              && BUFFER_LIVE_P (XBUFFER (p->buffer)))
            /* If a window we restore gets another buffer, record the
               window's old buffer.  */
            call1 (Qrecord_window_buffer, window);
@@ -5768,7 +5767,7 @@ the return value is nil.  Otherwise the value is t.  */)
          if (NILP (p->buffer))
            /* An internal window.  */
            wset_buffer (w, p->buffer);
-          else if (!NILP (BVAR (XBUFFER (p->buffer), name)))
+          else if (BUFFER_LIVE_P (XBUFFER (p->buffer)))
            /* If saved buffer is alive, install it.  */
            {
              wset_buffer (w, p->buffer);
@@ -5787,7 +5786,7 @@ the return value is nil.  Otherwise the value is t.  */)
                Fgoto_char (w->pointm);
             }
           else if (!NILP (w->buffer)
-                    && !NILP (BVAR (XBUFFER (w->buffer), name)))
+                    && BUFFER_LIVE_P (XBUFFER (w->buffer)))
             /* Keep window's old buffer; make sure the markers are
                real.  */
             {
diff --git a/src/xdisp.c b/src/xdisp.c
index 3536e04fe8d..ef36cf5c867 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -273,7 +273,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
 #include <limits.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "keyboard.h"
@@ -3671,7 +3670,7 @@ handle_fontified_prop (struct it *it)
        }
      /* There isn't much we can reasonably do to protect against
         misbehaving fontification, but here's a fig leaf.  */
-      else if (!NILP (BVAR (obuf, name)))
+      else if (BUFFER_LIVE_P (obuf))
        set_buffer_internal_1 (obuf);
      /* The fontification code may have added/removed text.
@@ -9345,12 +9344,6 @@ add_to_log (const char *format, Lisp_Object arg1, Lisp_Object arg2)
  struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
  USE_SAFE_ALLOCA;
-  /* Do nothing if called asynchronously.  Inserting text into
-     a buffer may call after-change-functions and alike and
-     that would means running Lisp asynchronously.  */
-  if (handling_signal)
-    return;
  fmt = msg = Qnil;
  GCPRO4 (fmt, msg, arg1, arg2);
@@ -9963,7 +9956,7 @@ ensure_echo_area_buffers (void)
  for (i = 0; i < 2; ++i)
    if (!BUFFERP (echo_buffer[i])
-        || NILP (BVAR (XBUFFER (echo_buffer[i]), name)))
+        || !BUFFER_LIVE_P (XBUFFER (echo_buffer[i])))
      {
        char name[30];
        Lisp_Object old_buffer;
@@ -21144,8 +21137,7 @@ are the selected window and the WINDOW's buffer).  */)
    : EQ (face, Qtool_bar) ? TOOL_BAR_FACE_ID
    : DEFAULT_FACE_ID;
-  if (XBUFFER (buffer) != current_buffer)
+  old_buffer = current_buffer;
-    old_buffer = current_buffer;
  /* Save things including mode_line_proptrans_alist,
     and set that to nil so that we don't alter the outer value.  */
@@ -21156,8 +21148,7 @@ are the selected window and the WINDOW's buffer).  */)
  mode_line_proptrans_alist = Qnil;
  Fselect_window (window, Qt);
-  if (old_buffer)
+  set_buffer_internal_1 (XBUFFER (buffer));
-    set_buffer_internal_1 (XBUFFER (buffer));
  init_iterator (&it, w, -1, -1, NULL, face_id);
@@ -23167,7 +23158,8 @@ right_overwritten (struct glyph_string *s)
    {
      int x = 0, i;
      struct glyph *glyphs = s->row->glyphs[s->area];
-      int first = (s->first_glyph - glyphs) + (s->cmp ? 1 : s->nchars);
+      int first = (s->first_glyph - glyphs
+                   + (s->first_glyph->type == COMPOSITE_GLYPH ? 1 : s->nchars));
      int end = s->row->used[s->area];
      for (i = first; i < end && s->right_overhang > x; ++i)
@@ -23190,7 +23182,8 @@ right_overwriting (struct glyph_string *s)
  int i, k, x;
  int end = s->row->used[s->area];
  struct glyph *glyphs = s->row->glyphs[s->area];
-  int first = (s->first_glyph - glyphs) + (s->cmp ? 1 : s->nchars);
+  int first = (s->first_glyph - glyphs
+               + (s->first_glyph->type == COMPOSITE_GLYPH ? 1 : s->nchars));
  k = -1;
  x = 0;
diff --git a/src/xfaces.c b/src/xfaces.c
index c113c1a37b7..c240a05c6c0 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -204,7 +204,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <stdio.h>              /* This needs to be before termchar.h */
-#include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/xfns.c b/src/xfns.c
index 90b54d12345..8304a3df04f 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
 #include <math.h>
-#include <setjmp.h>
 #include <unistd.h>
 /* This makes the fields of a Display accessible, in Xlib header files.  */
diff --git a/src/xfont.c b/src/xfont.c
index 7755b780815..1f2fd13f1b7 100644
--- a/src/xfont.c
+++ b/src/xfont.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <X11/Xlib.h>
 #include "lisp.h"
diff --git a/src/xftfont.c b/src/xftfont.c
index 404b9124099..9f52eb8b233 100644
--- a/src/xftfont.c
+++ b/src/xftfont.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include <X11/Xlib.h>
 #include <X11/Xft/Xft.h>
diff --git a/src/xgselect.c b/src/xgselect.c
index 5f4c7edfb79..c161564a322 100644
--- a/src/xgselect.c
+++ b/src/xgselect.c
@@ -19,14 +19,12 @@ along with GNU Emacs.  If not, see <http§://www.gnu.org/licenses/>.  */
 #include <config.h>
-#include <setjmp.h>
 #include "xgselect.h"
 #if defined (USE_GTK) || defined (HAVE_GCONF) || defined (HAVE_GSETTINGS)
 #include <glib.h>
 #include <errno.h>
-#include <setjmp.h>
 #include "xterm.h"
 int
diff --git a/src/xmenu.c b/src/xmenu.c
index 605db13e149..d03a4bc974b 100644
--- a/src/xmenu.c
+++ b/src/xmenu.c
@@ -33,7 +33,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "keyboard.h"
diff --git a/src/xml.c b/src/xml.c
index 7bc6130b8b1..b668525cf26 100644
--- a/src/xml.c
+++ b/src/xml.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #ifdef HAVE_LIBXML2
-#include <setjmp.h>
 #include <libxml/tree.h>
 #include <libxml/parser.h>
 #include <libxml/HTMLparser.h>
diff --git a/src/xrdb.c b/src/xrdb.c
index 624bafa5e92..73672c9617c 100644
--- a/src/xrdb.c
+++ b/src/xrdb.c
@@ -26,7 +26,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <epaths.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
diff --git a/src/xselect.c b/src/xselect.c
index 5a3b7452c6d..ab199e0b9b9 100644
--- a/src/xselect.c
+++ b/src/xselect.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <limits.h>
 #include <stdio.h>      /* termhooks.h needs this */
-#include <setjmp.h>
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
diff --git a/src/xsettings.c b/src/xsettings.c
index a28d75d9422..58c84495489 100644
--- a/src/xsettings.c
+++ b/src/xsettings.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <float.h>
 #include <limits.h>
-#include <setjmp.h>
 #include <fcntl.h>
 #include "lisp.h"
 #include "xterm.h"
@@ -711,12 +710,12 @@ apply_xft_settings (struct x_display_info *dpyinfo,
      if (send_event_p)
        store_config_changed_event (Qfont_render,
                                    XCAR (dpyinfo->name_list_element));
-      Vxft_settings 
+      Vxft_settings
        = make_formatted_string (buf, format,
                                 oldsettings.aa, oldsettings.hinting,
                                 oldsettings.rgba, oldsettings.lcdfilter,
                                 oldsettings.hintstyle, oldsettings.dpi);
-      
    }
  else
    FcPatternDestroy (pat);
diff --git a/src/xsmfns.c b/src/xsmfns.c
index cddbb2aae86..8067899f931 100644
--- a/src/xsmfns.c
+++ b/src/xsmfns.c
@@ -29,7 +29,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <unistd.h>
 #include <sys/param.h>
 #include <stdio.h>
-#include <setjmp.h>
 #include "lisp.h"
 #include "systime.h"
diff --git a/src/xterm.c b/src/xterm.c
index 8a702800c38..5bc87d0ec64 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
-#include <setjmp.h>
 #ifdef HAVE_X_WINDOWS
@@ -47,7 +46,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <fcntl.h>
 #include <errno.h>
-#include <setjmp.h>
 #include <sys/stat.h>
 /* Caused redefinition of DBL_DIG on Netbsd; seems not to be needed.  */
 /* #include <sys/param.h>  */
@@ -7140,25 +7138,17 @@ XTread_socket (struct terminal *terminal, int expected, struct input_event *hold
  if (interrupt_input_blocked)
    {
      interrupt_input_pending = 1;
-#ifdef SYNC_INPUT
      pending_signals = 1;
-#endif
      return -1;
    }
  interrupt_input_pending = 0;
-#ifdef SYNC_INPUT
  pending_signals = pending_atimers;
-#endif
  BLOCK_INPUT;
  /* So people can tell when we have read the available input.  */
  input_signal_count++;
-#ifndef SYNC_INPUT
-  ++handling_signal;
-#endif
  /* For debugging, this gives a way to fake an I/O error.  */
  if (terminal->display_info.x == XTread_socket_fake_io_error)
    {
@@ -7247,9 +7237,6 @@ XTread_socket (struct terminal *terminal, int expected, struct input_event *hold
      pending_autoraise_frame = 0;
    }
-#ifndef SYNC_INPUT
-  --handling_signal;
-#endif
  UNBLOCK_INPUT;
  return count;
@@ -7804,7 +7791,6 @@ x_connection_closed (Display *dpy, const char *error_message)
  error_msg = alloca (strlen (error_message) + 1);
  strcpy (error_msg, error_message);
-  handling_signal = 0;
  /* Inhibit redisplay while frames are being deleted. */
  specbind (Qinhibit_redisplay, Qt);
@@ -7892,7 +7878,7 @@ For details, see etc/PROBLEMS.\n",
  {
    sigset_t unblocked;
    sigemptyset (&unblocked);
-#ifdef SIGIO
+#ifdef USABLE_SIGIO
    sigaddset (&unblocked, SIGIO);
 #endif
    sigaddset (&unblocked, SIGALRM);
@@ -10439,10 +10425,8 @@ x_term_init (Lisp_Object display_name, char *xrm_option, char *resource_name)
  fcntl (connection, F_SETOWN, getpid ());
 #endif /* ! defined (F_SETOWN) */
-#ifdef SIGIO
  if (interrupt_input)
    init_sigio (connection);
-#endif /* ! defined (SIGIO) */
 #ifdef USE_LUCID
  {