* lisp/startup.el (command-line): Default to lexical-binding in *scratch*.
(normal-no-mouse-startup-screen, command-line-1):
Use startup--get-buffer-create-scratch.
(command-line-1):
* lisp/simple.el (eval-expression):
* lisp/server.el (server-eval-and-print): Use lexical-binding to
evaluate the expression.
(server-execute): Use startup--get-buffer-create-scratch.
* lisp/ielm.el (inferior-emacs-lisp-mode): Default to lexical-binding.

E.g., on typing the closing delimiter of a string continued onto a second
line, the opening delimiter retained its font-lock-warning-face.

* lisp/progmodes/cc-defs.el (c-c++-raw-string-opener-re)
(c-c++-raw-string-opener-1-re): New constants.
(c-sub-at-c++-raw-string-opener, c-at-c++-raw-string-opener): New macros.

* lisp/progmodes/cc-engine.el (c-raw-string-pos)
(c-depropertize-raw-strings-in-region, c-after-change-unmark-raw-strings):
Replace uses of open-coded raw string regexps by the new constants and macros
in cc-defs.el.

* lisp/progmodes/cc-fonts.el (c-font-lock-raw-strings): Ditto

* lisp/progmodes/cc-mode.el (c-before-change-check-unbalanced-strings): Set
c-new-BEG to the beginning of the string when we encounter its closing ".
When not in a raw string, but in a string, clear syntax-table properties from
its delimiters and set c-new-BEG/END to its limits.
(c-after-change-mark-abnormal-strings): When applying syntax-table properties
to string delimiters, also set c-new-BEG/END to ensure subsequent
fontification.

* lisp/wdired.el (wdired--restore-dired-filename-prop): When
dired-listing-switches includes "F" or "classify", don't treat
appended indicator characters as part of the file name (bug#34915).

* test/lisp/wdired-tests.el (wdired-test-bug34915): New test.

Without this fix, linking emacsclient fails with ‘Undefined
symbol eaccess’ on Solaris 10 sparc.
* lib-src/Makefile.in (LIB_EACCESS): New macro.
(emacsclient${EXEEXT}, emacsclientw${EXEEXT}): Use it.

These are where changing the identifier in a raw string delimiter causes
different delimiters to match eachother.

* lisp/progmodes/cc-engine.el (c-raw-string-end-delim-disrupted): New
variable.
(c-before-change-check-raw-strings): Use new variable.
(c-after-change-unmark-raw-strings): When typing into an opening delimiter or
altering its close delimiter causes the opening delimiter to match a later
closing delimiter, clear all syntax-table char properties from the opening
delimiter onwards, and set c-new-END to point max.  Also, when changing a
closing delimiter, check whether its new value matches a previously open
opening delimiter earlier in the buffer, and amend the syntax-table text
properties appropriately.

(sql-is-sqli-buffer-p): New function.
(sql-generate-unique-sqli-buffer-name): Refactor and use it.
(sql-product-interactive): Simplify name logic.
* test/lisp/progmodes/sql-tests.el
(sql-tests-placeholder-filter-harness): New macro.
(sql-tests-placeholder-filter-simple)
(sql-tests-placeholder-filter-ampersand)
(sql-tests-placeholder-filter-period): Refactored tests and use macro.
(sql-tests-buffer-naming-harness): New macro.
(sql-tests-buffer-naming-default)
(sql-tests-buffer-naming-multiple)
(sql-tests-buffer-naming-explicit)
(sql-tests-buffer-naming-universal-argument)
(sql-tests-buffer-naming-existing): New tests.

* lib-src/emacsclient.c (set_local_socket):
Use faccessat with AT_EACCESS instead of using euidaccess.
* admin/merge-gnulib, lib/gnulib.mk.in, m4/gnulib-comp.m4:
Revert previous change.

* admin/merge-gnulib (GNULIB_MODULES): Add euidaccess.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

* lisp/obsolete/ws-mode.el (ws-search-direction, ws-error, ws-end-block):
(ws-mark-word, ws-undo, ws-goto-last-cursorposition, ws-last-error):
(ws-kill-bol): Remove full stops from message string endings.  Minor
formatting tweaks.

* lisp/obsolete/ws-mode.el: Turn on lexical-binding.  Update commentary.
(wordstar): New custom group.
(wordstar-mode-lighter): New custom variable.
(wordstar-mode): Declare with define-minor-mode.
(turn-on-wordstar-mode): New function.
(global-wordstar-mode): New function.  Use previous new function.

* lisp/progmodes/project.el (project--find-regexp-in-files):
Add an explicit '-e' before the pattern.  Fixing the ability to
search for '--'.  Reported by Juri Linkov <juri@linkov.net>.

Remember action and delete it from display-buffer-overriding-action afterwards

Add support for a new preprocessor macro EMACS_MODULE_HAVE_MPZ_T to
emacs-module.h.  If this macro is defined, assume that mpz_t is
already defined and don’t include gmp.h.

Don’t document the new macro for now, as it’s unclear whether we want
to support this in modules outside the Emacs tree.

* src/emacs-module.h.in: Allow user to prevent inclusion of gmp.h.

* src/emacs-module.c: Use mini-gmp if GMP is unavailable.  Don’t
include gmp.h.

* src/lisp.h: Don’t require gmp.h.  It’s not needed for lisp.h.

* test/Makefile.in (GMP_LIB, GMP_OBJ): New variables.
($(test_module)): Use them.

* test/data/emacs-module/mod-test.c: Use mini-gmp if GMP is unavailable.

* test/Makefile.in (GMP_LIB): Define variable.
($(test_module)): Use it.

* src/lisp.h: Remove include of emacs-module.h.  Remove definition
of Lisp_Module_Function structure.

* src/emacs-module.c (module_function_documentation)
(module_function_address): New accessor functions for module function
fields.
(emacs_subr, struct Lisp_Module_Function): Move from lisp.h.

* src/print.c (print_vectorlike):
* src/doc.c (Fdocumentation): Use the new accessor functions.

* src/lisp.h (PVECHEADERSIZE): New macro.
(XSETPVECTYPESIZE): Use it.
* src/search.c (syms_of_search): No need to initialize or
staticpro last_thing_searched or saved_last_thing_searched, as
the thread code arranges for initialization and GC.
* src/thread.c (main_thread): Initialize statically.
(Fmake_mutex, Fmake_condition_variable, Fmake_thread):
Use ALLOCATE_ZEROED_PSEUDOVECTOR rather than zeroing by hand.
(mark_one_thread): No need to mark Lisp_Object members.
(init_main_thread, init_threads_once): Remove.  All uses removed.

* Makefile.in (CONFIG_STATUS_FILES_IN): Add
src/emacs-module.h.in.

* lisp/emacs-lisp/timer.el (timer-event-handler): Fix the
comparison between next invocation time and current time.

* src/xdisp.c (pos_visible_p): Account for line-number display
width when CHARPOS is covered by display property that begins
at the 2nd display element of a screen line.  (Bug#35404)

* src/timefns.c (timespec_to_lisp): Fix a typo in function
definition.

* doc/lispref/internals.texi (Module Values): Clarify that the
truncation is towards negative infinity.

* test/data/emacs-module/mod-test.c (Fmod_test_nanoseconds): Add test
function.
(emacs_module_init): Define it.

* test/src/emacs-module-tests.el (mod-test-nanoseconds): New unit test.

make_time is documented to return a (TICKS . HZ) pair, so we can’t use
make_lisp_time.  Introduce a new conversion function instead.

* src/emacs-module.c (module_make_time): Use timespec_to_lisp to
correct return type.

* src/timefns.c (timespec_to_lisp): New function.
(make_lisp_time): Use it.

* test/src/emacs-module-tests.el (mod-test-add-nanosecond/valid):
Check return type.

* src/module-env-27.h: Add new module functions to convert big
integers.

* src/emacs-module.h.in (emacs_mpz): Define if GMP is available.

* src/emacs-module.c (module_extract_big_integer)
(module_make_big_integer): New functions.
(initialize_environment): Use them.

* test/data/emacs-module/mod-test.c (Fmod_test_double): New test
function.
(emacs_module_init): Define it.

* test/src/emacs-module-tests.el (mod-test-double): New unit test.

* doc/lispref/internals.texi (Module Values): Document new functions.

Time values are a fundamental data type, and such conversions are hard
to implement within modules because of the various forms of time
values in Emacs Lisp.  Adding dedicated conversion functions can
significantly simplify module code dealing with times.

This approach uses nanosecond precision.  While Emacs in theory has
support for higher-precision time values, in practice most languages
and standards, such as POSIX, C, Java, and Go, have settled on
nanosecond-precision integers to represent time.

* src/emacs-module.h.in: Add header for struct timespec.

* src/module-env-27.h: Add module functions for time conversion.

* src/emacs-module.c (module_extract_time, module_make_time): New
functions.
(initialize_environment): Use them.

* test/data/emacs-module/mod-test.c (Fmod_test_add_nanosecond): New
test function.
(emacs_module_init): Define it.

* test/src/emacs-module-tests.el (mod-test-add-nanosecond/valid)
(mod-test-add-nanosecond/nil, mod-test-add-nanosecond/invalid): New
unit tests.

* doc/lispref/internals.texi (Module Values): Document time
conversion functions.

This reverts commit 64d0cd98.

Rationale: any font-related code and comments, even if unused
for decades, serves as important source of useful information
in an area of Emacs code that is notoriously under-documented.

Please do NOT remove this stuff until we have an active
expert in this are on board, who will then decide whether
this can be retired.

* configure.ac: Check cairo early.  Don't try Xft if cairo is used.
* lwlib/lwlib-utils.h [USE_CAIRO]: Include cairo.h and fontconfig.h.
(XftFont, XftDraw, XftColor, XGlyphInfo) [USE_CAIRO]: New typedefs.
(XftFontOpenName, XftFontClose, XftDrawCreate, XftDrawDestroy)
(XftDrawRect, XftDrawStringUtf8, XftTextExtentsUtf8) [USE_CAIRO]: New macros.
(crxft_font_open_name, crxft_font_close, crxft_draw_create)
(crxft_draw_rect, crxft_draw_string, crxft_text_extents) [USE_CAIRO]: New
externs.
* lwlib/lwlib-utils.c [USE_CAIRO]: Include math.h, cairo-ft.h, and
cairo-xlib.h.
(crxft_font_open_name, crxft_font_close, crxft_draw_create)
(crxft_set_source_color, crxft_draw_rect, crxft_draw_string)
(crxft_text_extents) [USE_CAIRO]: New Xft compatibility functions.
* lwlib/xlwmenuP.h [USE_CAIRO]: Include lwlib-utils.h.
* lwlib/xlwmenu.c (display_menu_item) [USE_CAIRO]: Call
cairo_surface_mark_dirty and cairo_surface_flush.
* lwlib/lwlib-Xaw.c [USE_CAIRO]: Include stdlib.h and lwlib-utils.h.
(draw_text) [USE_CAIRO]: Call cairo_surface_flush.
* src/xsettings.c [USE_CAIRO]: Include fontconfig.h
(apply_xft_settings) [!HAVE_XFT]: Don't call XftDefaultSubstitute or
XftDefaultSet.
* lwlib/lwlib-Xaw.c:
* lwlib/lwlib-int.h:
* lwlib/xlwmenu.c:
* lwlib/xlwmenuP.h:
* src/xrdb.c:
* src/xsettings.c:
* src/xterm.c: Replace all #ifdef HAVE_XFT with #if defined USE_CAIRO ||
defined HAVE_XFT.
* src/xfns.c (x_default_font_parameter): Replace #ifdef HAVE_XFT with #if
defined	USE_CAIRO || defined HAVE_XFT.

Enable lexical-binding.
(cl-print-compiled, cl-print-compiled-button): Declare.
(timer-list-mode): Add spacing to align the header.

These directives are in files that are compiled only if the
symbols are defined.
* src/gfilenotify.c: Remove unnecessary ‘#ifdef HAVE_GFILENOTIFY’.
* src/inotify.c: Remove unnecessary ‘#ifdef HAVE_INOTIFY’.
* src/kqueue.c: Remove unnecessary ‘#ifdef HAVE_KQUEUE’.

* src/font.c (LSTRING_HEADER_SIZE, LSTRING_GLYPH_SIZE, check_gstring)
(check_otf_features, otf_list, otf_tag_symbol, otf_open)
(font_otf_capability, generate_otf_features)
(font_otf_DeviceTable, font_otf_ValueRecord)
(font_otf_Anchor, Ffont_drive_otf, Ffont_otf_alternates)
(Fdraw_string, syms_of_font): Remove "experimental and not
tested much" code that has been "#if 0"-ed out for more than a
decade and which was getting in the way of maintenance.

This provides more debugging hints for callers.

* src/emacs-module.c (module_copy_string_contents): Use three-argument
form of args-out-of-range.

INT_TO_INTEGER is more obviously correct and means we don’t have to
worry about data type sizes and signedness.

* src/json.c (json_parse_error): Use INT_TO_INTEGER.  The tiny
performance gain of make_fixed_natnum isn’t worth the trouble then
signaling an error.

* lisp/autorevert.el
(auto-revert-notify-watch-descriptor-hash-list):
Rename to auto-revert--buffers-by-watch-descriptor.  Improved doc string.
(auto-revert-notify-rm-watch, auto-revert-notify-add-watch,
auto-revert-notify-handler): Use new name.

* doc/lispref/processes.texi (Asynchronous Processes):
(Accepting Output): Remote processes cannot use a pipe process for
stderr.

Thanks to Dmitry Gutov <dgutov@yandex.ru> for running many
benchmarks and for useful discussions.
* src/json.c (json_make_string): Speed up parsing of JSON
strings by optimizing the normal case of a valid UTF-8 string
being returned from libjansson.  (Bug#31138)

* test/src/json-tests.el (json-parse-string/null): Make JSON object
syntactically valid.  This test is supposed to check whether an
escaped null character causes an error, but without quoting the string
it would be syntactically invalid in any case.