Support text shaping with HarfBuzz

The code to support HarfBuzz was written by these individuals:

  Khaled Hosny <dr.khaled.hosny@gmail.com>
  YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
  Eli Zaretskii <eliz@gnu.org>

* src/xftfont.c (xftfont_list): Call ftfont_list2.
(xftfont_match): Call ftfont_match2.
(xftfont_open) [HAVE_HARFBUZZ]: Set the font driver to
xfthbfont_driver as required.  Reset xftfont_info->hb_font to
NULL.
(xftfont_close) [HAVE_HARFBUZZ]: Dispose of the hb_font object.
(xftfont_shape): Accept an additional argument DIRECTION and
pass it to ftfont_shape.
(xfthbfont_list, xfthbfont_match, xfthbfont_begin_hb_font)
(xfthbfont_end_hb_font) [HAVE_HARFBUZZ]: New functions.
(syms_of_xftfont): New DEFSYM 'xfthb'.
(syms_of_xftfont_for_pdumper) [HAVE_HARFBUZZ]: Initialize
xfthbfont_driver.

* src/xfns.c (Fx_create_frame, x_create_tip_frame)
[HAVE_HARFBUZZ]: Register the HarfBuzz font driver.

* src/w32uniscribe.c (bswap_32) [HAVE_HARFBUZZ]: Define to use
the builtin for GCC 4.3.9 and newer; else use byteswap.h from
Gnulib.
(struct uniscribe_font_info): New member 'scale'.  The member
'cache' is now used both by Uniscribe and HarfBuzz backends.
(uniscribe_open): Set the font backend as required by the font
entity's font_type field.
(uniscribe_close) [HAVE_HARFBUZZ]: Dispose of the hb_font
object.
(uniscribe_shape): Accept an additional argument DIRECTION.
(w32hb_list, w32hb_match, free_cb, w32hb_get_font_table)
(w32hb_get_font, w32hb_encode_char, w32hb_begin_font)
(w32hb_get_variation_glyphs, load_harfbuzz_funcs)
[HAVE_HARFBUZZ]: New functions.
(syms_of_w32uniscribe_for_pdumper): Initialize
harfbuzz_font_driver if loading the requisite functions from
the HarfBuzz DLL succeeded.

* src/w32font.c (syms_of_w32font): New DEFSYM 'harfbuzz'.

* src/w32fns.c (Fx_create_frame, w32_create_tip_frame):
Determine whether we should register the HarfBuzz backend, or
Uniscribe backend, or both for the new frame.

* src/w32common.h (hbfont_init_w32_funcs) [HAVE_HARFBUZZ]: Add
prototype.

* src/macfont.m (lgstring_direction): New enumeration.
(mac_font_shape_1, mac_screen_font_shape, macfont_shape):
Accept an additional argument DIRECTION; all callers changed.

* src/lisp.h (get_unicode_property): Add prototype.

* src/hbfont.c: New file.

* src/ftxfont.c (ftxfont_list): Call ftfont_list2.
(ftxfont_match): Call ftfont_match2.

* src/ftfont.h [HAVE_HARFBUZZ]: Include hb.h and hb-ft.h.
(struct font_info): New member hb_font.

* src/ftfont.c (ftfont_list2, ftfont_list_family): New functions.
(ftfont_open) [HAVE_HARFBUZZ]: Reset ftfont_info->hb_font to
NULL.  Set the font backend to fthbfont_driver when required.
(ftfont_close) [HAVE_HARFBUZZ]: Dispose of ftfont_info->hb_font.
(ftfont_glyph_metrics): New function.
(ftfont_text_extents): Call ftfont_glyph_metrics instead of
FT_Load_Glyph.
(ftfont_shape): Accept an additional argument DIRECTION.
(ftfont_variation_glyphs) [!HAVE_OTF_GET_VARIATION_GLYPHS]:
Support for variation glyphs without FLT.
(fthbfont_begin_hb_font) [HAVE_HARFBUZZ]: New function.
(syms_of_ftfont): New DEFSYM freetypehb.
(syms_of_ftfont_for_pdumper): Initialize fthbfont_driver.

* src/ftcrfont.c (ftcrfont_list): Call ftfont_list2.
(ftcrfont_match): Call ftfont_match2.
(ftcrfont_open) [HAVE_HARFBUZZ]: Set the font backend to
ftcrhbfont_driver as required.  Reset ftcrfont_info->hb_font
to NULL.
(ftcrfont_close) [HAVE_HARFBUZZ]: Discard of
ftcrfont_info->hb_font.
(ftcrfont_shape): Pass DIRECTION to ftfont_shape.
(ftcrhbfont_list, ftcrhbfont_match)
(ftcrhbfont_begin_hb_font, ftcrhbfont_end_hb_font)
[HAVE_HARFBUZZ]: New functions.
(syms_of_ftcrfont): New DEFSYM ftcrhb.
(syms_of_ftcrfont_for_pdumper): Initialize ftcrhbfont_driver.

* src/font.h [HAVE_HARFBUZZ]: Include hb.h.
(struct font_driver): Update comments and function signatures
to reflect the new argument DIRECTION accepted by the 'shape'
method.  New methods 'begin_hb_font' and 'end_hb_font'.
(hbfont_shape, hbfont_combining_capability)
(fthbfont_begin_hb_font) [HAVE_HARFBUZZ]: Add prototypes.

* src/font.c (Ffont_shape_gstring): Accept an additional
argument DIRECTION, and pass it to the font driver's 'shape'
method.
(Ffont_variation_glyphs): Doc fix.
(syms_of_font): New DEFSYMS L2R and R2L.

* src/composite.h (composition_reseat_it): Adjust prototype.

* src/composite.c (autocmp_chars): Accept additional argument
DIRECTION, and pass it to auto-composition-function.  All
callers changed.
(composition_reseat_it): Accept additional argument
BIDI_LEVEL, and use it to determine the DIRECTION argument to
be passed to autocmp_chars.  All callers changed.
(syms_of_composite) <auto-composition-function>: Improve the
doc string; document the meaning of the new argument
DIRECTION.

* src/chartab.c (get_unicode_property): New function,
refactored from the body of get-unicode-property-internal.
(Fget_unicode_property_internal): Call get_unicode_property
after validating the input arguments.

* src/Makefile.in (HARFBUZZ_CFLAGS, HARFBUZZ_LIBS): New macros.
(EMACS_CFLAGS): Use HARFBUZZ_CFLAGS.
(SOME_MACHINE_OBJECTS): Add hbfont.o
(LIBES): Add HARFBUZZ_LIBS.

* lisp/language/tv-util.el (tai-viet-composition-function):
* lisp/language/thai-util.el (thai-composition-function):
* lisp/language/misc-lang.el (arabic-shape-gstring):
* lisp/language/lao-util.el (lao-composition-function):
* lisp/language/japanese.el (compose-gstring-for-variation-glyph):
* lisp/language/hebrew.el (hebrew-shape-gstring):
* lisp/language/ethio-util.el (ethio-composition-function):
* lisp/composite.el (compose-chars-after)
(compose-gstring-for-graphic)
(compose-gstring-for-dotted-circle)
(compose-gstring-for-terminal, auto-compose-chars): All
composition functions that call shapers now accept an
additional argument DIRECTION, either L2R or R2L.

* etc/NEWS: Document the HarfBuzz support.

* etc/HELLO: Add diacritics to Hebrew greetings.

* doc/lispref/frames.texi (Font and Color Parameters):
* doc/emacs/msdos.texi (Windows Fonts): Describe the
'harfbuzz' font backend on MS-Windows and how it is preferred
to 'uniscribe'.

* configure.ac (--wthout-harfbuzz): New option.
(HAVE_HARFBUZZ): New tests.
(FONT_OBJ) [HAVE_HARFBUZZ]: Add hbfont.o
(emacs_config_features): Add HARFBUZZ.

* admin/nt/dist-build/build-dep-zips.py: Add HarfBuzz dependency.

Merge remote-tracking branch 'origin/harfbuzz'

Fix failures of term-tests on MS-Widows

* test/lisp/term-tests.el (term-simple-lines)
(term-carriage-return, term-line-wrap, term-cursor-movement)
(term-scrolling-region, term-set-directory)
(term-line-wrapping-then-motion, term-to-margin): Skip tests
on MS-Windows and MS-DOS.

Consider line spacing and font height when deriving proc window size

* lisp/window.el (window-adjust-process-window-size): Use
  window-screen-lines instead of window-body-height.
* lisp/term.el (term-mode): Use window-screen-lines to set the initial
  window height.

Fix image_set_crop yet again

* src/image.c (image_set_crop) [HAVE_NATIVE_TRANSFORMS]: Don't call
compute_image_size, as it is already called from image_set_size.
(image_set_size, image_set_crop) [HAVE_NATIVE_TRANSFORMS]: Use harmless
matrix transformation code also for USE_CAIRO and HAVE_NTGUI cases,
though image_set_transform is not yet implemented on them.

Avoid compiler warning in copy-file-range.c on MS-Windows

* nt/mingw-cfg.site (gl_cv_func_copy_file_range): Set to "yes",
to avoid compiling lib/copy-file-range.c on MS-Windows.

Fix recently-introduced image_set_crop typo

* src/image.c (image_set_crop) [!HAVE_NATIVE_TRANSFORMS]:
Don’t call compute_image_size, as it does not exist and its
result is not needed.

Use copy_file_range to copy files

The copy_file_range syscall (introduced in Linux kernel
version 4.5) can copy files more efficiently via server-side
copy etc.
* admin/merge-gnulib (GNULIB_MODULES): Add copy-file-range.
* lib/copy-file-range.c, m4/copy-file-range.m4:
New files, copied from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* src/fileio.c (Fcopy_file): Try copy_file_range first,
falling back on read+write only if copy_file_range failed or
if the input is empty and so could be a /proc file.

Update from Gnulib

This incorporates:
2019-06-04 copy-file-range: new module
2019-05-28 binaty-io: O_BINARY on consoles no longer fails
* doc/misc/texinfo.tex, lib/binary-io.c, lib/binary-io.h:
* lib/unistd.in.h, m4/unistd_h.m4: Copy from Gnulib.
* lib/gnulib.mk.in: Regenerate.

Add "pin" to password-word-equivalents (Bug#35523)

* lisp/international/mule-conf.el (password-word-equivalents): Add "pin".
* test/lisp/comint-tests.el (comint-testsuite-password-strings): Add
test case.

Fix overflow issues in image rotation

Also, do some refactoring to simplify code.
* src/dispextern.h (INIT_MATRIX, COPY_MATRIX, MULT_MATRICES): Remove.
* src/image.c (matrix3x3): New type, replacing all uses of 3x3 double.
(matrix3x3_copy, matrix3x3_mult): New functions, replacing
COPY_MATRIX, MULT_MATRICES.  Replace INIT_MATRIX by C initializers.
(image_set_rotation): Use Fmod to avoid undefined behavior on
double-to-int conversion and to reduce bignum rotations correctly.
(image_set_crop): Finish up previous correction, by not re-setting
width and height if compute_image_size has set them.
Prefer shifting right by 1 to dividing by 2 if either will do.

Fix redisplay glitches with RTL composed text

* src/xdisp.c (init_to_row_end): Fail if the first visible
position on the line following ROW is bidi-reordered and could
be composed.  (Bug#35811)

lisp/gnus/message.el (message--send-mail-maybe-partially): Extract

lisp/gnus/message.el (message--check-continuation-headers): Extract

lisp/gnus/message.el (message--fold-long-headers): Add docstring

Restore height and with from that were accidentally removed

See 610fb73ab6d7a22b722f523d6ebc4aa8fa1db7c9
USE_CARIO needs these.

Check rcirc-server for auto authentication (Bug#10162)

Since the hostname returned by irc.freenode.net can be something other
than irc.freenode.net, e.g. niven.freenode.net, the entries for
rcirc-authinfo and rcirc-server-alist will not match.
* lisp/net/rcirc.el (rcirc-handler-001): Check rcirc-server (the
hostname connected to) instead of rcirc-server-name (the hostname
returned), this corresponds with what rcirc-authenticate does.
Moreover, if rcirc-auto-authenticate-flag is set, check the
corresponding rcirc-authinfo, regardless of whether the
rcirc-authenticate-before-join must happen.

Copyright-paperwork-exempt: yes

Keep nxml prolog updated via syntax-propertize

Instead of using after-change-functions.  Also, stop consulting
nxml-prolog-regions during syntax-propertize.  It turns out the
problems fixed by using prolog information are actually due to using
the wrong syntax table during propertizing.  This was fixed in
2019-06-04 "* lisp/emacs-lisp/syntax.el: Use syntax-ppss-table for
syntax-propertize." so consulting the prolog data is no longer needed.
* lisp/nxml/nxml-rap.el (nxml-maybe-rescan-prolog): Remove.
* lisp/nxml/nxml-mode.el (nxml-mode): Stop using it.
(nxml-syntax-propertize): Don't use nxml-prolog-regions, just call
nxml-scan-prolog if needed before delegating to
sgml-syntax-propertize.
* test/lisp/nxml/nxml-mode-tests.el (nxml-mode-edit-prolog): New test.

Add native image rotation and cropping

* lisp/image.el (image--get-imagemagick-and-warn): Only fallback to
ImageMagick if native transforms aren't available.
* src/dispextern.h (INIT_MATRIX, COPY_MATRIX, MULT_MATRICES): New
macros for matrix manipulation.
(HAVE_NATIVE_SCALING, HAVE_NATIVE_TRANSFORMS): Rename and change all
relevant locations.
* src/image.c (x_set_image_rotation):
(x_set_transform): New functions.
(x_set_image_size): Use transform matrix for resizing under X and NS.
(x_set_image_crop): New function.
(lookup_image): Use the new transform functions.
(Fimage_scaling_p, Fimage_transforms_p): Rename and update all
callers.
* src/nsimage.m (ns_load_image): Remove rotation code.
(ns_image_set_transform): New function.
([EmacsImage dealloc]): Release the saved transform.
([EmacsImage rotate:]): Remove unneeded method.
([EmacsImage setTransform:]): New method.
* src/nsterm.h (EmacsImage): Add transform property and update method
definitions.
* src/nsterm.m (ns_dumpglyphs_image): Use the transform to draw the
image correctly.
* src/xterm.c (x_composite_image): Use PictOpSrc as we don't care
about alpha values here.
* doc/lispref/display.texi (Image Descriptors): Add :rotation.
(ImageMagick Images): Remove :rotation.

No longer add debug symbols to release build

* admin/nt/dist-build/build-zips.sh: Remove -g3 from release build and
  install with install-strip

* lisp/wid-edit.el (widget-choose): Use display-buffer-in-direction

to display buffer in bottom direction with fit-window-to-buffer.

* lisp/proced.el (proced-with-processes-buffer): Idem.  (Bug#35592)

* doc/misc/tramp.texi (Obtaining Tramp): Explain version scheme.

(Traces and Profiles): Add `tramp-verbose' to @vindex.

; Add test for Bug#36092

* test/lisp/nxml/nxml-mode-tests.el (nxml-mode->-after-quote): New
test.

Do not use syntax-ppss-table in syntax-propertize when nil (Bug#36095)

* lisp/emacs-lisp/syntax.el (syntax-propertize): Use (syntax-table)
instead of syntax-ppss-table when the latter is nil.

* lisp/emacs-lisp/syntax.el: Use syntax-ppss-table for syntax-propertize.

`syntax-ppss` uses `syntax-ppss-table` while parsing the buffer as well
as when it calls `syntax-propertize`, but `syntax-propertize` can also
be called directly rather than via `syntax-ppss` so it needs to explicitly
use `syntax-ppss-table` as well in order to avoid using sometimes one
table and sometimes another.

(syntax-ppss-table): Move before new use.
(syntax-propertize): Use it.

Remove retired maintainers from comments

* lisp/international/quail.el, lisp/language/ind-util.el:
* lisp/language/indian.el, lisp/mail/smtpmail.el, lisp/mwheel.el:
* lisp/obsolete/longlines.el, lisp/progmodes/idlw-complete-structtag.el:
* lisp/progmodes/idlw-help.el, lisp/progmodes/idlw-shell.el:
* lisp/progmodes/idlw-toolbar.el, lisp/progmodes/idlwave.el:
* lisp/progmodes/simula.el, lisp/ps-print.el, lisp/ps-samp.el:
Remove Maintainer: lines for maintainers who have retired.

* lisp/emacs-lisp/thunk.el (thunk-delay): Fix memory leak

Get rid of references to the free variables of `body` once the thunk has
been forced (bug#30626).

* sgml-mode.el (sgml-syntax-propertize-rules): More verbose comments

Specify the matching chars for JSX open/close parenthesis

* lisp/progmodes/js.el (js-jsx--syntax-propertize-tag): Indicate the
matching parenthesis character (since JSX’s < and > aren’t typical
parenthesis) for the sake of packages like rainbow-delimiters which
need that information.

Revert "Add extra text property to fix issue with js2-mode integration"

This reverts commit 382a508ed21e4f12ace9f8871818e25235e8f05e.

We ended up deciding against using this in js2-mode.  Instead,
js2-mode may eventually use js-mode’s syntax-propertize-function to
set syntax-table text properties.

Update lispref spellfile

* doc/lispref/spellfile: Omit words no longer in the manual.
How is this spellfile used?  Does anybody use it any more?

Adjust comments/debug to match C bignum code

* doc/lispintro/emacs-lisp-intro.texi (Digression into C):
Adjust to match current C code.
* lisp/emacs-lisp/ert.el (ert--force-message-log-buffer-truncation):
Simplify.
* src/.gdbinit (Lisp_Object_Printer.to_string): Return
a string that says "make_fixnum", not "make_number".

Always allow at least double-precision bignums

Without this fix, Emacs can get into a tight loop reporting
a range error when calculating timestamps.
* doc/lispref/numbers.texi (Integer Basics):
* src/alloc.c (syms_of_alloc): Document this.
* src/bignum.c (make_bignum_bits): Always allow bignums
of at least twice the width of (u)intmax_t.

* lisp/gnus/message.el (message-send-mail): Tweak last commit

Keep nxml-prolog-end up to date (Bug#18871)

The change on 2016-01-16 "lisp/nxml: Use syntax-tables for comments"
removed the update of nxml-prolog-end, although it already failed to
work correctly after 2013-10-07 "* lisp/nxml/nxml-mode.el: Use
lexical-binding and syntax-propertize."
* lisp/nxml/nxml-rap.el: New function.
* lisp/nxml/nxml-mode.el (nxml-mode): Add it to
after-change-functions.

Don't sgml-syntax-propertize-inside XML prolog (Bug#32823)

* lisp/nxml/nxml-mode.el (nxml-syntax-propertize): New function.
(nxml-mode): Use it as the syntax-propertize-function.
* test/lisp/nxml/nxml-mode-tests.el (nxml-mode-doctype-and-quote-syntax)
(nxml-mode-prolog-comment): New tests.

Don't fontify text outside of SGML/XML tags (Bug#33887)

* lisp/textmodes/sgml-mode.el (sgml-font-lock-syntactic-face): New
function.
(sgml-mode):
* lisp/nxml/nxml-mode.el (nxml-mode): Use it as
font-lock-syntactic-face-function value.

Fix some SGML syntax edge cases (Bug#33887)

* lisp/textmodes/sgml-mode.el (sgml-syntax-propertize-rules): Handle
single and double quotes symmetrically.  Don't skip quoted comment
enders.
* test/lisp/textmodes/sgml-mode-tests.el (sgml-tests--quotes-syntax):
Add more test cases.
(sgml-mode-quote-in-long-text): New test.

Stronger check for Tramp method

* lisp/net/tramp-gvfs.el (tramp-gvfs-maybe-open-connection):
* lisp/net/tramp-rclone.el (tramp-rclone-maybe-open-connection):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-maybe-open-connection):
Use `tramp-get-connection-name'.

* lisp/net/tramp-sh.el (tramp-sh-handle-make-symbolic-link):
* lisp/net/tramp-smb.el (tramp-smb-handle-make-symbolic-link):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-make-symbolic-link):
Don't check remote TARGET.

* lisp/net/tramp.el (tramp-dissect-file-name): Check for proper method.
(tramp-file-name-for-operation): Take only 2nd argument into
account for file name handler.
(tramp-file-name-handler): Suppress checks for `file-remote-p'.

* test/lisp/net/tramp-archive-tests.el
(tramp-archive-test02-file-name-dissect): Suppress check for wrong
method.

* test/lisp/net/tramp-tests.el (tramp--test-instrument-test-case):
Dump *all* Tramp buffers.
(tramp-test02-file-name-dissect)
(tramp-test02-file-name-dissect-simplified)
(tramp-test02-file-name-dissect-separate): Check also wrong method.
(tramp-test03-file-name-defaults): Check, that the respective
Tramp package is loaded.
(tramp-test04-substitute-in-file-name)
(tramp-test05-expand-file-name)
(tramp-test06-directory-file-name, tramp-test44-auto-load):
Suppress check for wrong method.
(tramp-test30-make-process): Remove instrumentation code.
(tramp-test31-interrupt-process, tramp-test36-vc-registered):
Guarantee that connection is established prior starting process.

* src/xterm.c (x_scroll_run) [USE_CAIRO]: Dirty only destination rectangle.

* src/image.c (cr_create_cr_surface_from_image): Add const to variable `key'.

Let untarring (and hence package installation) go faster (Bug#35909)

* lisp/subr.el (progress-reporter-update)
(progress-reporter-force-update, progress-reporter-do-update): Accept
new optional argument, SUFFIX.
* doc/lispref/display.texi (Progress): Document it.
* etc/NEWS: Announce it.
* lisp/tar-mode.el (tar-untar-buffer): Use a progress reporter instead
of calling message.  Suppress message from write-region.  Let-bind
write-region-inhibit-fsync to t.

Update dependencies

* admin/nt/dist-build/build-dep-zips.py: Add harfbuzz as dependency

User-friendly display of error messages at the end of minibuffer

* lisp/simple.el (minibuffer-setup-hook): Add minibuffer-error-initialize.
(minibuffer-error-initialize, minibuffer-error-function): New functions.
(Bug#34939)

* lisp/char-fold.el (char-fold-make-table): New function

with body extracted from INITVALUE of defconst (bug#35689).
Bind search-spaces-regexp to nil (bug#35802).

* test/lisp/char-fold-tests.el: Relocate helpers to file beginning.
(char-fold--test-bug-35802): New test.

* lisp/gnus/gnus-async.el: Use lexical-binding

Remove redundant :group args.
(gnus-async-post-fetch-function): Make it always be a function.
(gnus-make-async-article-function, gnus-async-prefetch-headers):
Use a closure rather than `(lambda ...)

lisp/gnus/message.el (message-send-mail): Don't wrongly assert on Unicode msg

Using this setting:

    (setq message-send-mail-function 'message-send-mail-with-sendmail)
    (setq sendmail-program "msmtp")

the message seding is handled by an external program, so no Unicode
encoding is performed in Emacs. Thus Emacs must not assert that the
Unicode encoding was performed.

* help-fns.el (help-fns--first-release): Do not fail if no release is found.

* gnus-(sum|async).el: Eliminate assumptions about gnus-data format

* lisp/gnus/gnus-async.el (gnus-async-with-semaphore): Use `declare`.
(gnus-async-prefetch-next): Don't assume gnus-data-number == car.

* lisp/gnus/gnus-sum.el (gnus-data-find-in): New function.
(gnus-data-find, gnus-data-find-list): Use it.
(gnus-summary-article-subject): Make it a function.
(gnus--dummy-data-list): New const.
(gnus-update-summary-mark-positions): Use it.

* gnus.el: Fix cycle in eager macroexpansion

* lisp/gnus/gnus-sum.el (gnus-data): Use cl-defstruct.
(gnus-data-set-pos, gnus-data-set-header, gnus-data-set-mark)
(gnus-data-set-number): Delete macros; use `setf` instead.
(gnus-data-unread-p, gnus-data-read-p, gnus-data-pseudo-p, gnus-data-find)
(gnus-summary-skip-intangible, gnus-summary-article-number):
Redefine as inlinable functions rather than macros.

* lisp/gnus/gnus.el: Adjust autoloads for the macros turned functions.

* lisp/help-fns.el: Make hyperlink for the "first release" info

* lisp/help-fns.el (help-fns--first-release): Return a "button".
(help-fns--mention-first-release): Preserve the string's text-properties.

* lisp/help-mode.el (help-news): New button type.

; * src/hbfont.c (hbfont_shape): Fix a typo in a comment.

Change default offset of CC Mode syntactic symbol inlambda to 0

It's previous default was c-lineup-inexpr-block.  This change is mainly to
prevent excessive indentation of the innards of C++ lambda functions.

* lisp/progmodes/cc-vars.el (c-offsets-alist): Amend the offset for inlambda
to 0.

* doc/misc/cc-mode.texi (FAQ): Amend the answer to the question about this
matter.

Implement the get_variation_glyphs method for FreeType >= 2.3.6

* configure.ac: Check availability of FT_Face_GetCharVariantIndex.

* src/ftfont.c (ftfont_variation_glyphs) [HAVE_FT_FACE_GETCHARVARIANTINDEX]:
Add function implementation.

* src/ftcrfont.c (ftcrfont_variation_glyphs)
[HAVE_FT_FACE_GETCHARVARIANTINDEX]: Use function implementation for
HAVE_OTF_GET_VARIATION_GLYPHS.

* src/ftfont.c (ftfont_driver) [HAVE_FT_FACE_GETCHARVARIANTINDEX]:
* src/xftfont.c (xftfont_driver) [HAVE_FT_FACE_GETCHARVARIANTINDEX]:
* src/ftxfont.c (ftxfont_driver) [HAVE_FT_FACE_GETCHARVARIANTINDEX]:
* src/ftcrfont.c (ftcrfont_driver) [HAVE_FT_FACE_GETCHARVARIANTINDEX]:
Populate the get_variation_glyphs method.

Revert previous commit

This reverts commit 1ab69630dcb8c7a1b1b4171211a7c8ebf11b0d1c.
It has a wrong commit message.

Make fthbfont and derivatives use common HarfBuzz code in hbfont.c

* src/font.h (fthbfont_shape, fthbfont_combining_capability)
[HAVE_HARFBUZZ]: Remove prototypes.

* src/ftfont.c: Don't include math.h.
(uni_combining, uni_general, uni_mirroring, get_hb_unicode_funcs)
(fthbfont_shape_by_hb, fthbfont_combining_capability, fthbfont_shape)
[HAVE_HARFBUZZ]: Remove functions.

* src/ftfont.c (syms_of_ftfont_for_pdumper) [HAVE_HARFBUZZ]:
* src/xftfont.c (syms_of_xftfont_for_pdumper) [HAVE_HARFBUZZ]:
* src/ftcrfont.c (syms_of_ftcrfont_for_pdumper) [HAVE_HARFBUZZ]: Use
hbfont_shape and hbfont_combining_capability for fthbfont_shape and
fthbfont_combining_capability, respectively.

Make fthbfont and derivatives use common HarfBuzz code in hbfont.c

* src/font.h (fthbfont_shape, fthbfont_combining_capability)
[HAVE_HARFBUZZ]: Remove prototypes.

* src/ftfont.c: Don't include math.h.
(uni_combining, uni_general, uni_mirroring, get_hb_unicode_funcs)
(fthbfont_shape_by_hb, fthbfont_combining_capability, fthbfont_shape)
[HAVE_HARFBUZZ]: Remove functions.

* src/ftfont.c (syms_of_ftfont_for_pdumper) [HAVE_HARFBUZZ]:
* src/xftfont.c (syms_of_xftfont_for_pdumper) [HAVE_HARFBUZZ]:
* src/ftcrfont.c (syms_of_ftcrfont_for_pdumper) [HAVE_HARFBUZZ]: Use
hbfont_shape and hbfont_combining_capability instead of fthbfont_shape
and fthbfont_combining_capability, respectively.

Skip some flymake tests on hydra.nixos.org

* test/lisp/progmodes/flymake-tests.el (perl-backend)
(included-c-header-files, recurrent-backend):
Skip on hydra.nixos due to frequent intermittent failures.  (Bug#32764)

Use lexical-binding in morse.el and studly.el and add tests

* lisp/play/morse.el: Use lexical-binding.
* lisp/play/studly.el: Use lexical-binding.
* test/lisp/play/morse-tests.el: New file.
* test/lisp/play/studly-tests.el: New file.

Use lexical-binding in paragraphs.el and add tests

* lisp/textmodes/paragraphs.el: Use lexical-binding.
(repunctuate-sentences): Make it work non-interactively.
* test/lisp/textmodes/paragraphs-tests.el: New file.

Fix .gitignore spec for personal customizations

Problem reported by Mauro Aranda (Bug#35945).
* .gitignore: Replace .dir-locals?.el with .dir-locals-2.el.

Tune cl-assoc

* lisp/emacs-lisp/cl-seq.el (cl-assoc): Use assq for fixnums.

Fix `cl-member' and `cl-assoc' for bignums

* lisp/emacs-lisp/cl-seq.el (cl-member, cl-assoc): Work with bignums.
* test/lisp/emacs-lisp/cl-seq-tests.el (cl-seq-bignum-eql): New.

; Add NEWS entry for previous change

Make rcirc PART and QUIT reasons customizable (Bug#12857)

* rcirc.el: (rcirc-default-part-reason, rcirc-default-quit-reason):
New customizable vars.
(rcirc-cmd-quit, rcirc-cmd-part): Consult them.

Copyright-paperwork-exempt: yes

Handle argument to rcirc /part properly (Bug#11157)

* lisp/net/rcirc.el (part): Split out channel name and part reason.
* doc/misc/rcirc.texi (rcirc commands): Clarify that channel name may
be provided to /part.

* lisp/net/rcirc.el: Remove redundant :group usage

... and empty Todo comment section.

; Fix stray merge conflict

Debug and disentangle the literal cacheing in CC Mode

(Final Commit)

* lisp/progmodes/cc-engine.el (c-semi-trim-near-cache): Correct a comparison
with the wrong ...-limit variable.
(c-semi-pp-to-literal): Remove a wrong setting of c-lit-pos-cache-limit.
(c-full-get-near-cache-entry): Eliminate extravagant and unneeded coding.
(c-state-cache-init, c-record-parse-state-state): No longer manipulate
c-lit-pos-cache, which is no longer regarded as part of c-parse-state.

* lisp/progmodes/cc-mode.el (c-basic-common-init): Call
c-truncate-lit-pos-cache to initialize the literal cache.

* lisp/progmodes/cc-engine.el: Permute certain literal cacheing functions

Tidy up the literal cacheing in CC Mode, optimizing c-full-pp-to-literal

(Intermediate commit)

* lisp/progmodes/cc-engine.el, lisp/progmodes/cc-fonts.el
* lisp/progmodes/cc-mode.el : Rename:
c-state-semi-nonlit-pos-cache -> c-lit-pos-cache,
c-state-semi-nonlit-pos-cache-limit -> c-lit-pos-cache-limit,
c-state-semi-nonlit-near-cache -> c-semi-lit-near-cache,
c-truncate-semi-nonlit-pos-cache -> c-truncate-lit-pos-cache,
c-state-semi-trim-near-cache -> c-semi-trim-near-cache,
c-state-semi-get-near-cache-entry -> c-semi-get-near-cache-entry,
c-state-semi-put-near-cache-entry -> c-semi-put-near-cache-entry,
c-state-semi-pp-to-literal -> c-semi-pp-to-literal,
c-state-full-pp-to-literal -> c-full-pp-to-literal,
c-state-semi-trim-cache -> c-trim-lit-pos-cache.

* lisp/progmodes/cc-engine.el (c-semi-near-cache-limit): New variable.
(c-truncate-lit-pos-cache): This now truncates the cache variables for all
three lit- sub-caches.
(c-semi-put-near-cache-entry): Increase c-semi-near-cache-limit to the
position of the new entry.
(c-full-near-cache-limit, c-full-lit-near-cache): New variables.
(c-full-trim-near-cache, c-full-get-near-cache-entry)
(c-full-put-near-cache-entry): New functions.
(c-full-pp-to-literal): Amend to use the new functions, and to optimize the
use of the available caches, similarly to c-semi-pp-to-literal.

; src/w32uniscribe.c: Remove redundant include of math.h.

; Unmaintain

Port hbfont.c to GCC 9 with --enable-gcc-warnings

* src/hbfont.c (hbfont_shape): Use ptrdiff_t, not int,
for indexes that in theory might overflow int.
Add UNINIT to pacify GCC 9 and omit an unnecessary initialization.

Merge from origin/emacs-26

008b263 (origin/emacs-26, emacs-26) * lisp/gnus/gnus.el: Mark autoloa...
daf32f1 Speed up redisplay of HELLO
d8a6d82 Improve documentation of 'safe-local-variable' property

# Conflicts:
# etc/HELLO

; Merge from origin/emacs-26

The following commit was skipped:

b3df372 * lisp/emacs-lisp/package.el: Obey buffer-file-coding-system ...

Merge from origin/emacs-26

134edc1 Warn about wrong number of args for subrs (Bug#35767)
5f01af6 Use plain symbols for eieio type descriptors (Bug#29220)
4b24b01 Pacify GCC 9 -Wredundant-decls

; Merge from origin/emacs-26

The following commits were skipped:

7871c3d Pacify librsvg 2.45.1 and later
d93f4bd Simplify xd_signature to pacify GCC 9

Merge from origin/emacs-26

b2e44b4 Pacify GCC when compiling unexelf.c on Fedora 30

; Merge from origin/emacs-26

The following commit was skipped:

fa9e575 Suppress GCC 9 “no longer supported” messages

Merge from origin/emacs-26

1b2f83b Fix docstring of bookmark-get-bookmark

; Merge from origin/emacs-26

The following commit was skipped:

c4d4dcf Avoid infloop in read-multiple-choice (Bug#32257)

Merge from origin/emacs-26

2168165 ; * doc/lispref/nonascii.texi (Explicit Encoding): Fix typo.
8f18d12 Improve documentation of decoding into a unibyte buffer
7681a57 Remove redundants "See" before @xref or @pxref (Bug#35793)
9bee762 ; * src/coding.c: Improve commentary.  (Bug#34765)
e61349c Fix customization type of recentf-max-saved-items

# Conflicts:
# src/coding.c

; Auto-commit of loaddefs files.

* lisp/gnus/gnus.el: Mark autoloaded macros as such.

This avoids a build failure.

; * src/font.c (Ffont_variation_glyphs): Doc fix.

Implement the get_variation_glyphs method for HarfBuzz on MS-Windows

* src/w32uniscribe.c [HAVE_HARFBUZZ]: DEF_DLL_FN
hb_font_get_variation_glyph.
(hb_font_get_variation_glyph): New redirection macro.
(w32hb_get_variation_glyphs): New function.
(load_harfbuzz_funcs): Load hb_font_get_variation_glyph.
(syms_of_w32uniscribe_for_pdumper): Populate the
get_variation_glyphs method of harfbuzz_font_driver.

; * src/hbfont.c: Fix commentary.

Speed up redisplay of HELLO

* etc/HELLO: Set 'inhibit-compacting-font-caches' non-nil
locally.  (Bug#36032)

* lisp/files.el: Add 'inhibit-compacting-font-caches' to the
list of built-in variables for which we set up
'safe-local-variable' properties.

Use lexical-binding in page.el and add tests

* lisp/textmodes/page.el: Use lexical-binding.
(forward-page): Replace `(if x nil y)' with `(unless x y)'.

* test/lisp/textmodes/page-tests.el: New file with tests for page.el.

; * etc/NEWS: Reflect changes in font backend loading.

Update the documentation due to changes in loading font backends

* doc/emacs/msdos.texi (Windows Fonts): Reflect the fact that
Uniscribe is not enabled by default.

Prefer HarfBuzz to Uniscribe on MS-Windows

* src/w32fns.c (Fx_create_frame, w32_create_tip_frame):
Register the Uniscribe font backend only if HarfBuzz is not
available, or if explicitly requested via frame parameters
or resources.

Move common HarfBuzz code to a common file hbfont.c

* src/hbfont.c: New file, with code moved from w32uniscribe.c
and renamed/modified as appropriate.
* src/w32uniscribe.c: Move to hbfont.c DEF_DLL_FN and macro
definitions for HarfBuzz functions used in hbfont.c
(load_harfbuzz_funcs): Move loading of HarfBuzz functions used
by hbfont.c to hbfont.c:hbfont_init_w32_funcs, and call that
function from here.
(syms_of_w32uniscribe_for_pdumper): Fill the 'shape' and
'combining_capability' members with hbfont.c function names.
* src/w32common.h (hbfont_init_w32_funcs) [HAVE_HARFBUZZ]: Add
prototype.
* src/font.h (hbfont_shape, hbfont_combining_capability)
[HAVE_HARFBUZZ]: Add prototypes.
* src/Makefile.in (SOME_MACHINE_OBJECTS): Add hbfont.o.

* configure.ac (FONT_OBJ): Add hbfont.o if HAVE_HARFBUZZ.

Use lexical-binding in timezone.el and add tests

* lisp/timezone.el: Use lexical-binding.
* test/lisp/timezone-tests.el: New file.

Improve documentation of 'safe-local-variable' property

* doc/lispref/variables.texi (File Local Variables): Document
how to define 'safe-local-variable' properties for built-in
variables.

Use lexical-binding in autoinsert.el and add tests

* lisp/autoinsert.el: Use lexical-binding.
Remove redundant :group args.
(auto-insert): Simplify.

* test/lisp/autoinsert-tests.el: New file with tests for
autoinsert.el.

; * etc/NEWS: Mention support for HarfBuzz on MS-Windows.

Unbreak MinGW64 build with pthreads.h installed

* nt/mingw-cfg.site (gl_cv_func_pthread_sigmask_macro): Set to
"no", to avoid compiling Gnulib's pthread_sigmask.c.
Reported by Richard Copley <rcopley@gmail.com>.

Enhance Hebrew display in HELLO

* etc/HELLO: Show off display of Hebrew with diacriticals
(a.k.a. "nikkud").