* src/editfns.c (NOTE_DELETE, NOTE_INSERT): Avoid unnecessary parens.
(Freplace_buffer_contents): Check args before returning results.
Avoid integer overflow when computing too_expensive, and work even
if MAX-COSTS is bignum.  Call alloca and/or malloc just once, not
three times.
(set_bit, bit_is_set): Simplify micro-optimization by using eassume.

* src/editfns.c (rbc_quitcounter): Remove; the quitcounter
is now part of the context.
(EXTRA_CONTEXT_FIELDS): Remove unused member early_abort_tests.
Add jmp, quitcounter.
(Freplace_buffer_contents): Use setjmp/longjmp to recover from
a compareseq that runs too long.  Omit unnecessary rarely_quit
call.
(buffer_chars_equal): Occasionally check for early abort and
longjmp out if so (Bug#43016).

* doc/lispref/positions.texi (Text Lines, Screen Lines): Add index
entries.
* lisp/simple.el (move-beginning-of-line): Remove incorrect mention of
images, and reference beginning-of-visual-line.
* src/editfns.c (Fline_beginning_position): Reference
`vertical-motion' (bug#35899).

GCC has removed the -fcheck-pointer bounds option, and the Linux
kernel has also removed support for Intel MPX, so there’s no point
to keeping this debugging option within Emacs.
* src/bytecode.c (BYTE_CODE_THREADED):
* src/lisp.h (DEFINE_LISP_SYMBOL, XSYMBOL, make_lisp_symbol):
Assume __CHKP__ is not defined.
* src/ptr-bounds.h: Remove.  All uses of ptr_bounds_clip,
ptr_bounds_copy, ptr_bounds_init, ptr_bounds_set removed.

7be160d800 Improve "Help Summary" section in user manual
f6d6ccc984 Clarify message-sendmail-extra-arguments docstring
95fde1a851 * src/editfns.c (Fformat): Small documentation fix.

* src/editfns.c (Fstring_to_char): Simplify.

* src/editfns.c (Fstring_to_char): Simplify.

This tweak improved the CPU time performance of
‘make compile-always’ by about 1.8% on my platform.

* src/editfns.c (Ftranslate_region_internal): Add UNINIT
to pacify gcc -Og x86-64 (GCC 9.3.1 20200317 (Red Hat 9.3.1-1)).

* src/buffer.h (fetch_char_advance, fetch_char_advance_no_check)
(buf_next_char_len, next_char_len, buf_prev_char_len)
(prev_char_len, inc_both, dec_both): New inline functions,
replacing the old character.h macros FETCH_CHAR_ADVANCE,
FETCH_CHAR_ADVANCE_NO_CHECK, BUF_INC_POS, INC_POS, BUF_DEC_POS,
DEC_POS, INC_BOTH, DEC_BOTH respectively.  All callers changed.
These new functions all assume buffer primitives and so need
to be here rather than in character.h.
* src/casefiddle.c (make_char_unibyte): New static function,
replacing the old MAKE_CHAR_UNIBYTE macro.  All callers changed.
(do_casify_unibyte_string): Use SINGLE_BYTE_CHAR_P instead
of open-coding it.
* src/ccl.c (GET_TRANSLATION_TABLE): New static function,
replacing the old macro of the same name.
* src/character.c (string_char): Omit 2nd arg.  3rd arg can no
longer be NULL.  All callers changed.
* src/character.h (SINGLE_BYTE_CHAR_P): Move up.
(MAKE_CHAR_UNIBYTE, MAKE_CHAR_MULTIBYTE, PREV_CHAR_BOUNDARY)
(STRING_CHAR_AND_LENGTH, STRING_CHAR_ADVANCE)
(FETCH_STRING_CHAR_ADVANCE)
(FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE)
(FETCH_STRING_CHAR_ADVANCE_NO_CHECK, FETCH_CHAR_ADVANCE)
(FETCH_CHAR_ADVANCE_NO_CHECK, INC_POS, DEC_POS, INC_BOTH)
(DEC_BOTH, BUF_INC_POS, BUF_DEC_POS): Remove.
(make_char_multibyte): New static function, replacing
the old macro MAKE_CHAR_MULTIBYTE.  All callers changed.
(CHAR_STRING_ADVANCE): Remove; all callers changed to use
CHAR_STRING.
(NEXT_CHAR_BOUNDARY): Remove; it was unused.
(raw_prev_char_len): New inline function, replacing the
old PREV_CHAR_BOUNDARY macro.  All callers changed.
(string_char_and_length): New inline function, replacing the
old STRING_CHAR_AND_LENGTH macro.  All callers changed.
(STRING_CHAR): Rewrite in terms of string_char_and_length.
(string_char_advance): New inline function, replacing the old
STRING_CHAR_ADVANCE macro.  All callers changed.
(fetch_string_char_advance): New inline function, replacing the
old FETCH_STRING_CHAR_ADVANCE macro.  All callers changed.
(fetch_string_char_as_multibyte_advance): New inline function,
replacing the old FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE macro.
All callers changed.
(fetch_string_char_advance_no_check): New inline function,
replacing the old FETCH_STRING_CHAR_ADVANCE_NO_CHECK macro.  All
callers changed.
* src/regex-emacs.c (HEAD_ADDR_VSTRING): Remove; no longer used.
* src/syntax.c (scan_lists): Use dec_bytepos instead of
open-coding it.
* src/xdisp.c (string_char_and_length): Rename from
string_char_and_length to avoid name conflict with new function in
character.h.  All callers changed.

If a position argument to get-byte etc. is an out-of-range integer,
treat it the same regardless of whether it is a fixnum or a bignum.
* src/buffer.c (fix_position): New function.
* src/buffer.c (validate_region):
* src/character.c (Fget_byte):
* src/coding.c (Ffind_coding_systems_region_internal)
(Fcheck_coding_systems_region):
* src/composite.c (Ffind_composition_internal):
* src/editfns.c (Fposition_bytes, Fchar_after, Fchar_before)
(Finsert_buffer_substring, Fcompare_buffer_substrings)
(Fnarrow_to_region):
* src/fns.c (Fsecure_hash_algorithms):
* src/font.c (Finternal_char_font, Ffont_at):
* src/fringe.c (Ffringe_bitmaps_at_pos):
* src/search.c (search_command):
* src/textprop.c (get_char_property_and_overlay):
* src/window.c (Fpos_visible_in_window_p):
* src/xdisp.c (Fwindow_text_pixel_size):
Use it instead of CHECK_FIXNUM_COERCE_MARKER, so that
the code is simpler and treats bignums consistently with fixnums.
* src/buffer.h (CHECK_FIXNUM_COERCE_MARKER): Define here
rather than in lisp.h, and reimplement in terms of fix_position
so that it treats bignums consistently with fixnums.
* src/lisp.h (CHECK_FIXNUM_COERCE_MARKER): Move to buffer.h.
* src/textprop.c (validate_interval_range): Signal with original
bounds rather than modified ones.