Ignore some externally maintained files in AUTHORS

* admin/authors.el (authors-ignored-files): Ignore externally
maintained files.

* lisp/image-dired.el: Remove unnecessary 'declare-function'.

; * admin/MAINTAINERS: Add myself.

Change the call signature to keymap-substitute

* lisp/keymap.el (keymap-substitute): Make the keymap the first
parameter for symmetry with the other functions.
* lisp/emacs-lisp/shortdoc.el (keymaps):
* lisp/emacs-lisp/bytecomp.el (lambda): Adjust.

Merge from origin/emacs-28

fa0b34b716 * admin/authors.el (authors-ignored-files): Ignore some NE...
c25be3e7bb * lisp/tab-bar.el (tab-bar-select-tab): Add check for wc-f...
38d905abf9 * lisp/tab-bar.el: Doc fixes for commands bound to modifie...

Make bookmark-set prompt less confusing

* lisp/bookmark.el (bookmark-set): Make the prompt less confusing
(bug#51876).

Fix mh-mime build problem

* lisp/mh-e/mh-mime.el (mh-acros): Require to get mh-dlet*.

Temporarily mark two failing tests as unstable

* test/lisp/mh-e/mh-utils-tests.el
(mh-folder-completion-function-08-plus-slash)
(mh-folder-completion-function-09-plus-slash-tmp): Temporarily
mark two failing tests as unstable.

; * admin/automerge: Maintain.

Fix bookmark-bmenu-mode-map syntax

* lisp/bookmark.el (bookmark-bmenu-mode-map): Fix syntax in defvar-keymap.

Remove some references to XEmacs

* lisp/emulation/viper-cmd.el (viper-start-R-mode):
* lisp/emulation/viper-init.el (viper-window-display-p):
* lisp/emulation/viper-mous.el (viper-surrounding-word):
* lisp/mail/footnote.el (footnote-mode):
* lisp/textmodes/reftex-index.el: Remove some comments referring to
XEmacs.

Make mh-funcall-if-exists obsolete

* lisp/mh-e/mh-acros.el (mh-funcall-if-exists): Make obsolete.
* lisp/mh-e/mh-alias.el (mh-read-address):
* lisp/mh-e/mh-folder.el (mh-folder-mode):
* lisp/mh-e/mh-mime.el (mh-mm-display-part):
* lisp/mh-e/mh-show.el (mh-defun-show-buffer):
* lisp/mh-e/mh-speed.el (mh-speedbar-change-expand-button-char):
* lisp/mh-e/mh-tool-bar.el (mh-tool-bar-define):
* lisp/mh-e/mh-utils.el (mh-logo-display):
* lisp/mh-e/mh-xface.el (mh-face-display-function): Don't use
above obsolete macro.

Convert keymaps in bookmark.el to defvar-keymap

* lisp/bookmark.el (bookmark-map)
(bookmark-minibuffer-read-name-map)
(bookmark-edit-annotation-mode-map, bookmark-bmenu-mode-map):
Convert to defvar-keymap.

* lisp/rot13.el (rot13-translate-table): Make it a `translation-table`

(rot13-display-table): Use `dotimes`.

* admin/authors.el (authors-ignored-files): Ignore some NEWS files.

* admin/gitmerge.el (gitmerge-mode-map): Convert to defvar-keymap.

Update xwidget webkit history buffer more eagerly

* lisp/xwidget.el (xwidget-webkit-callback): Update history
buffer on each load-changed event.

Only set LANG if the ID is valid

* src/nsterm.m (ns_init_locale): Check the provided locale identifier
is available before trying to use it.

* lisp/tab-bar.el (tab-bar-select-tab): Add check for wc-frame (bug#51883).

* lisp/tab-bar.el: Doc fixes for commands bound to modifier keys.

(tab-bar-select-tab-modifiers)
(tab-bar-select-tab, tab-bar-switch-to-last-tab): Doc fixes.

Make keymap-unset work

* lisp/keymap.el (keymap-unset): Fix key syntax (bug#51897).

Put back documentation of legacy keymap functions

* doc/lispref/keymaps.texi (Low-Level Key Binding): Reinstate
documentation of legacy commands and functions.

Merge branch 'master' of git.savannah.gnu.org:/srv/git/emacs

Minor copyedits of recent documentation changes

* doc/lispref/keymaps.texi (Low-Level Key Binding): Minor changes
in wording and markup.

Some minor Tramp updates

* lisp/net/tramp-crypt.el (tramp-crypt-add-directory): Add comment.

* lisp/net/tramp.el (tramp-debug-buffer-command-completion-p)
(tramp-setup-debug-buffer): New defuns.
(tramp-get-debug-buffer): Call `tramp-setup-debug-buffer.

* test/lisp/net/tramp-tests.el (tramp-test07-abbreviate-file-name):
Extend test.

Fix compilation error in previous keymap.c change

* src/keymap.c (initial_define_lispy_key, define_as_prefix): Fix
--enable-checking error.

Lower xwidget views owned by parent when lowering frame

* src/xterm.c (x_lower_frame): Lower parent frame's xwidget
views as well.

* src/xwidget.h (lower_frame_xwidget_views):
* src/xwidget.c (lower_frame_xwidget_views): New function.

Add command to browse xwidget history

* doc/emacs/misc.texi (Embedded WebKit Widgets)
* etc/NEWS: Document `xwidget-webkit-browse-history'.

* lisp/xwidget.el (xwidget-webkit-mode-map): Bind "H" to
xwidget-webkit-browse-history.
(xwidget-webkit-import-widget): Set last session buffer correctly.
(xwidget-webkit-browse-history): New command.
(xwidget-webkit-history--session): New variable.

(xwidget-webkit-history--insert-item)
(xwidget-webkit-history-select-item)
(xwidget-webkit-history-reload): New functions.

(xwidget-webkit-history-mode): New major mode.

New X resource to control the border thickness of menus

* lwlib/xlwmenu.h (XtNborderThickness, XtCBorderThickness): New X
resource name.
* lwlib/xlwmenuP.h (XlwMenuPart): New border_thickness field.
* lwlib/xlwmenu.c (xlwMenuResources): Access the new resource.
(draw_shadow_rectangle): Use the new resource value.
* doc/emacs/xresources.texi (Lucid Resources): Document the new
resource (bug#51867).

Make results details in ert-run-tests-batch configurable

* lisp/emacs-lisp/ert.el (ert-batch-print-length)
(ert-batch-print-level,.ert-batch-backtrace-line-length)
(ert-batch-test, ert-run-tests-interactively): Added the three
variables, bound them to these settings when formatting batch
test results including backtraces. Removed the optional
parameters output-buffer & message-fn from
ert-run-tests-interactively.
* test/lisp/emacs-lisp/ert-tests.el
(ert-test-run-tests-interactively, ert-test-run-tests-batch): use
cl-letf to capture output, new tests resp.
* test/lisp/ert-x-tests.el (ert-test-run-tests-interactively-2):
Changed to use cl-letf to capture output instead of using
message-fn.
* lisp/emacs-lisp/backtrace.el (backtrace--line-length-or-nil)
(backtrace--print-func-and-args): Fixed a bug when setting
backtrace-line-length to nil by adding a new function to check
for that case & having backtrace--print-func-and-args use it.
* doc/misc/ert.texi: document the new variables & their usage
(bug#51037).

Start adjusting the manuals to talk about the keymap-* functions

* lisp/dired.el (dired--make-directory-clickable):
* doc/lispref/keymaps.texi (Keymaps):
(Key Sequences):
(Prefix Keys):
(Active Keymaps):
(Key Lookup):
(Functions for Key Lookup):
(Changing Key Bindings):
(Key Binding Commands):
(Tool Bar):
* doc/lispref/commands.texi (Interactive Codes):
(Event Examples):
(Event Mod):
* doc/emacs/kmacro.texi (Save Keyboard Macro):
* doc/emacs/custom.texi (Keymaps):
(Keymaps):
(Minibuffer Maps):
(Rebinding):
(Init Rebinding):
(Modifier Keys):
(Mouse Buttons):
(Init Examples):
(Init Non-ASCII): Adjust the documentation to remove description
of the old syntaxes, and use the new keymap-* functions.

* doc/lispref/keymaps.texi (Low-Level Key Binding): New node that
describes `define-key' and the old key syntaxes.

Adjust `defvar-keymap' and `define-keymap' to the new syntax

* lisp/vc/smerge-mode.el (smerge-basic-map):
* lisp/vc/pcvs.el (cvs-mode-map):
(cvs-minor-mode-prefix):
* lisp/vc/log-view.el (log-view-mode-map):
* lisp/vc/log-edit.el (log-edit-mode-map):
* lisp/vc/diff-mode.el (diff-mode-shared-map):
(diff-minor-mode-prefix):
* lisp/vc/cvs-status.el (cvs-status-mode-map):
* lisp/simple.el (special-mode-map):
* lisp/outline.el (outline--insert-open-button):
(outline--insert-close-button):
* lisp/net/shr.el (shr-map):
* lisp/net/eww.el (eww-link-keymap):
(eww-mode-map):
(eww-submit-map):
(eww-bookmark-mode-map):
(eww-history-mode-map):
(eww-buffers-mode-map):
* lisp/mh-e/mh-speed.el (:keymap):
* lisp/mh-e/mh-show.el (:keymap):
* lisp/mh-e/mh-search.el (:keymap):
* lisp/mh-e/mh-letter.el (:keymap):
* lisp/mh-e/mh-folder.el (:keymap):
* lisp/international/emoji.el (emoji-list-mode-map):
* lisp/gnus/spam.el (:keymap):
* lisp/gnus/mml.el (mml-mode-map):
* lisp/gnus/message.el (message-mode-map):
* lisp/gnus/gnus-undo.el (gnus-undo-mode-map):
* lisp/gnus/gnus-topic.el (gnus-topic-mode-map):
* lisp/gnus/gnus-sum.el (:keymap):
* lisp/gnus/gnus-srvr.el (gnus-server-mode-map):
(gnus-browse-mode-map):
* lisp/gnus/gnus-salt.el (gnus-pick-mode-map):
(gnus-tree-mode-map):
* lisp/gnus/gnus-msg.el (:prefix):
* lisp/gnus/gnus-ml.el (gnus-mailing-list-mode-map):
* lisp/gnus/gnus-kill.el (gnus-kill-file-mode-map):
* lisp/gnus/gnus-html.el (gnus-html-displayed-image-map):
* lisp/gnus/gnus-group.el (:keymap):
* lisp/gnus/gnus-eform.el (gnus-edit-form-mode-map):
* lisp/gnus/gnus-draft.el (gnus-draft-mode-map):
* lisp/gnus/gnus-dired.el (gnus-dired-mode-map):
* lisp/gnus/gnus-bookmark.el (gnus-bookmark-bmenu-mode-map):
* lisp/gnus/gnus-art.el (:keymap):
(gnus-article-edit-mode-map):
* lisp/gnus/gnus-agent.el (gnus-agent-group-mode-map):
(gnus-agent-summary-mode-map):
(gnus-agent-server-mode-map):
(gnus-category-mode-map): Adjust `defvar-keymap' and
`define-keymap' to the new syntax.

Add new 'keymap-*' functions

* lisp/keymap.el: New file with all the new keymap-* functions.

* lisp/loadup.el ("keymap"): Load.

* lisp/subr.el (kbd): Refactor out all the code to key-parse.
(define-key-after, keyboard-translate, global-set-key)
(local-set-key, global-unset-key, local-unset-key)
(local-key-binding, global-key-binding)
(substitute-key-definition): Note in doc strings that these are
legacy functions.
(define-keymap--define): Use keymap-set.

* lisp/emacs-lisp/byte-opt.el: Remove the optimizations for
defvar-keymap and define-keymap since the macros now only
understand the kbd syntax.
* lisp/emacs-lisp/bytecomp.el (byte-compile-define-keymap)
(byte-compile-define-keymap--define): Warn about invalid key
definitions in all keymap-* functions.

* lisp/emacs-lisp/shortdoc.el (keymaps): Add shortdocs form
keymap* functions.

* src/keymap.c (possibly_translate_key_sequence): Adjust callers
to key-valid-p and key-parse.
(syms_of_keymap): Adjust defs.

Allow removing keymap definitions

* src/keymap.c (initial_define_lispy_key): Adjust caller.
(store_in_keymap): Allow removing definitions in addition to
setting them to nil.
(Fdefine_key): Ditto.
(define_as_prefix): Adjust caller.

* src/term.c (term_get_fkeys_1): Adjust caller.

Make erc-mode noninteractive

* lisp/erc/erc.el (erc-mode): Mark it as noninteractive, because
using it from `M-x' will only lead to problems (bug#51841).

Merge from origin/emacs-28

e852822f3d Fix removal of fringe marks of deleted bookmarks
b418aad85a * lisp/repeat.el (repeat-echo-message): Bind message-log-m...
fe2ac7cb7c * lisp/repeat.el (describe-repeat-maps): Use help-fns--ana...
c840bfe7e1 * lisp/repeat.el: Detect changes in the minibuffer state (...
5044151486 Avoid segfaults due to freed face cache
199e2468d3 Doc fix; change recommended file name of custom-file

Fix handling of folder "+/" in MH-E

* lisp/mh-e/mh-utils.el (mh-sub-folders): Fix handling of "+/".
* test/lisp/mh-e/mh-utils-tests.el
(mh-folder-completion-function-08-plus-slash)
(mh-folder-completion-function-09-plus-slash-tmp):
Fix errors made importing tests from mh-unit.el; remove declaration
that these tests are expected to fail.

Fix checkdoc complaints in MH-E

* lisp/mh-e/mh-compat.el (mh-flet): Rewrite most of the docstring.
(mh-write-file-functions): Remove trailing space.
* lisp/mh-e-mh-scan.el (mh-scan-cmd-note-width): Break up a
line that was too long.

Fix recently changed wdired test on MS-Windows

* test/lisp/wdired-tests.el (wdired-test-bug34915): Don't try to
create a local socket on MS-Windows, as it is not supported on that
platform.  Problem reported by Robert Pluim <rpluim@gmail.com>.

Prevent xwidget windows from obscuring child frames

* src/xwidget.c (x_draw_xwidget_glyph_string): Lower view window
when creating it.

Fix xwidget isearch for queries that look like format strings

* lisp/xwidget.el (xwidget-webkit-isearch--update): Give special
treatment to messages.

Fix documentation string

* src/xwidget.c (Vxwidget_list, Vxwidget_views_list): Fix
horrid doc string.

Fix removal of fringe marks of deleted bookmarks

* lisp/bookmark.el (bookmark--remove-fringe-mark): The fringe
overlay is at BOL, not at POS.  (Bug#51233)

* lisp/repeat.el (repeat-echo-message): Bind message-log-max to nil.

Don't insert messages about repeatable keys in the *Messages* buffer.

* lisp/repeat.el (describe-repeat-maps): Use help-fns--analyze-function.

Print keys bound to commands in every keymap (bug#49265)

* lisp/repeat.el: Detect changes in the minibuffer state (bug#47566)

(repeat--prev-mb): New internal variable.
(repeat-post-hook): Check the property 'repeat-map' on the symbol
from 'this-command' in addition to 'real-this-command'.  Don't allow
repeatable maps in the activated minibuffer or in the minibuffer
from another command.  Set 'repeat--prev-mb' at the end.

Fix minor problems resulting from Tramp regression tests

* lisp/net/tramp-adb.el (tramp-adb-file-name-handler-alist):
* lisp/net/tramp-archive.el (tramp-archive-file-name-handler-alist):
* lisp/net/tramp-crypt.el (tramp-crypt-file-name-handler-alist):
* lisp/net/tramp-gvfs.el (tramp-gvfs-file-name-handler-alist):
* lisp/net/tramp-rclone.el (tramp-rclone-file-name-handler-alist):
* lisp/net/tramp-sshfs.el (tramp-sshfs-file-name-handler-alist):
Add comment.

* lisp/net/tramp-cache.el (tramp-flush-file-upper-properties):
FILE can be "~".

* lisp/net/tramp.el ('tramp-ensure-dissected-file-name):
Add `tramp-suppress-trace' property.
(tramp-get-debug-buffer): Add local key for debugging.
(tramp-handle-abbreviate-file-name): Adapt implementation.

* test/lisp/net/tramp-tests.el
(tramp-test07-abbreviate-file-name):
Adapt test.
(tramp-test17-insert-directory-one-file)
(tramp--test-check-files): Use proper `no-dir' argument for
`dired-get-filename'.

Avoid segfaults due to freed face cache

* src/xfaces.c (face_at_buffer_position): Make sure DEFAULT_FACE
is usable.  (Bug#51864)

Add another 'abbreviate-file-name' test

* test/lisp/files-tests.el
(files-tests-file-name-non-special-abbreviate-file-name): New test.

Support abbreviating home directory of Tramp filenames

* doc/lispref/files.texi (Magic File Names): Mention
'abbreviate-file-name' in the list of magic file name handlers.

* etc/NEWS: Announce the change.

* lisp/files.el (file-name-non-special):
* lisp/net/tramp.el (tramp-file-name-for-operation):
* lisp/net/tramp-sh.el (tramp-sh-file-name-handler-alist):
* lisp/net/tramp-smb.el (tramp-smb-file-name-handler-alist):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-file-name-handler-alist):
Add 'abbreviate-file-name'.

* lisp/files.el (directory-abbrev-make-regexp):
(directory-abbrev-apply): New functions.
(abbreviate-file-name): Check for file name handler.

* test/lisp/net/tramp-tests.el (tramp-test07-abbreviate-file-name):
New test.

Doc fix; change recommended file name of custom-file

* lisp/cus-edit.el (custom-file): Change file name recommendation to
match Info node '(emacs) Saving Customizations'.

Fix hanging wdired test

* test/lisp/wdired-tests.el (wdired-test-bug34915): Fix hanging
test.  Don't start the Emacs Server just to create a socket; just
create the socket manually.

Fix outline-cycle-buffer issue in `C-h b' buffers

* lisp/outline.el (outline--fix-up-all-buttons): Fix issue when
called after collapsing a buffer (bug#51855).

Allow mm-external-terminal-program to be a list of strings

* doc/misc/emacs-mime.texi (Display Customization): Document it.

* lisp/gnus/mm-decode.el (mm-external-terminal-program): Allow
being a list.

Fix handling of changed prefix keys in tutorial

* lisp/tutorial.el (tutorial--find-changed-keys): Use keymapp to
detect prefix definitions rather than hard-coding them.  A notable
omission from the hard-coded list was mode-specific-command-prefix,
whose subcommands are often rebound (bug#40725).

Merge from origin/emacs-28

044dd1e210 * rcirc.el (rcirc-define-command): Fix interactive-spec ge...

; Merge from origin/emacs-28

The following commit was skipped:

97059bcdff Fix `C-h k' in gnus-article-mode (don't merge)

Merge from origin/emacs-28

85ac0efe7c Fix semantic-symref-perform-search doc string

Fix xwidget-webkit-back-forward-list

* src/xwidget.c (Fxwidget_webkit_back_forward_list): Use correct
list variable in loop.

Stop assuming xwidget views will only be displayed in TEXT_AREA

* src/xterm.c (x_scroll_run): Use view->area when calculating
xwidget view clipping.

* src/xwidget.c (x_draw_xwidget_glyph_string): Set view->area
to s->area and use that instead.

* src/xwidget.h (struct xwidget_view): Add glyph row area field.

Prefer POSIX timers to timerfd timers

* src/atimer.c (set_alarm): Try to start a POSIX timer before
starting a timerfd timer.  On Cygwin, return if the POSIX timer is
started successfully. (Bug#51734)

* rcirc.el (rcirc-define-command): Fix interactive-spec generation

* rcirc.el (rcirc-define-command):  Wrap interactive spec in a list call.

* lisp/tab-line.el (tab-line-mode): Preserve existing value of tab-line-format

Keep the old value of tab-line-format when enabling tab-line-mode
and don't overwrite it with nil when disabling tab-line-mode (bug#51830).

* src/lread.c (read_escape): Fix handling of ?\C-<char> for chars 128-255

Fix `C-h k' in gnus-article-mode (don't merge)

* lisp/gnus/gnus-art.el (gnus-article-describe-key):
(gnus-article-describe-key-briefly): Fix `describe-key' calling
convention (bug#51796).

; Revert "* lisp/progmodes/python.el (python-forward-sexp-function): :version fix."

This reverts commit e6e29b435273ee9821b6536581bd151f3e50737d.
The commit was a mistake.

; * lisp/progmodes/python.el (python-forward-sexp-function): :version fix.

Fix recent documentation updates

* doc/lispref/text.texi (Special Properties): Improve wording.
Add cross-reference and index entry.
(Sticky Properties): Add indexing.

Fix semantic-symref-perform-search doc string

* lisp/cedet/semantic/symref/cscope.el (semantic-symref-perform-search):
Fix the docstring to refer to the correct tool (bug#51846).

Improve Tramp error handling

* doc/misc/tramp.texi (Frequently Asked Questions): Add another
`remote-file-error'.

* lisp/net/tramp.el (tramp-find-foreign-file-name-handler):
Improve error handling.

; Merge from origin/emacs-28

The following commit was skipped:

289f3a9 Add more files to be natively-compiled AOT

Merge from origin/emacs-28

5dbad52 gnus-summary-line-format doc string clarification
d4536ff Fix follow-scroll-down in a small buffer which starts slightl...

; Merge from origin/emacs-28

The following commits were skipped:

4802419 Fix compilation on MS-Windows
cc4edea Use posix_spawn if possible.

Merge from origin/emacs-28

a56dd60 Improve style and comments in font-related sources

Add more files to be natively-compiled AOT

* src/Makefile.in (elnlisp): Add emacs-lisp/gv.eln and other
missing dependencies of comp.el.

Expose xwidget navigation history to Lisp code

* doc/lispref/display.texi (Xwidgets): Document changes.
* etc/NEWS: Announce new function.
* src/xwidget.c (Fxwidget_webkit_back_forward_list): New
function.
(syms_of_xwidget): Define new subr.

Add `kill-xwidget'

* doc/lispref/display.texi (Xwidgets): Document 'kill-xwidget'.
* src/xwidget.c (kill_xwidget, Fkill_xwidget): New function.
(syms_of_xwidget): Define new subr.
(kill_buffer_xwidgets): Use `kill_xwidget' instead.

Fix previous -responsible-p change

* lisp/vc/vc-sccs.el (vc-sccs-responsible-p):
* lisp/vc/vc-rcs.el (vc-rcs-responsible-p):
* lisp/vc/vc-cvs.el (vc-cvs-responsible-p): Make the previous
change work with relative file names, too.

gnus-summary-line-format doc string clarification

* lisp/gnus/gnus.el (gnus-summary-line-format): Clarify the Date
part of the doc string (bug#51823).

Explain in the manual how to make `cursor-intangible' work

* doc/lispref/text.texi (Special Properties): Explain how to make
`cursor-intangible' work (bug#51095).

Fix crash in xwidget_end_redisplay

* src/xwidget.c (xwidget_end_redisplay): Always test if xv is
NULL.

Fix `C-h k' in gnus-article-mode

* lisp/gnus/gnus-art.el (gnus-article-describe-key):
(gnus-article-describe-key-briefly): Fix `describe-key' calling
convention (bug#51796).

Make all vc-*-responsible-p functions return a string

* lisp/vc/vc-sccs.el (vc-sccs-responsible-p):
* lisp/vc/vc-rcs.el (vc-rcs-responsible-p):
* lisp/vc/vc-dav.el (vc-dav-responsible-p):
* lisp/vc/vc-cvs.el (vc-cvs-responsible-p): Return a file name
instead of t when we get a match (which is what
vc-backend-for-registration expects) (bug#51800).

Fix customization group of python-forward-sexp-function

* lisp/progmodes/python.el (python-forward-sexp-function): Move from
the "Flymake integration" subsection to the "Navigation" subsection,
so that the option is sorted into the 'python' group rather than the
'python-flymake' group (bug#51807).

Fix Gnus gcc header tokenization

* lisp/gnus/gnus-msg.el (gnus-summary-resend-message-insert-gcc)
(gnus-inews-do-gcc): Fix tokenization of the gcc header.

Adjust build-dep-zips.py download link

* admin/nt/dist-build/build-dep-zips.py (download_source): Adjust
the download link (bug#40628).

Find most specific backend for `vc-backend-for-registration'.

* lisp/vc/vc.el (vc-backend-for-registration): Count file name
components instead of the length of the file name string (bug#50572).

Fix follow-scroll-down in a small buffer which starts slightly scrolled

This fixes bug #51814.

* lisp/follow.el (follow-scroll-down): Do away with the optimization of doing
vertical-motion over only one window.  Instead move over all windows, to
checck for being close to point-min, and setting point accordingly.

Fix compilation on MS-Windows

* src/callproc.c (emacs_spawn) <fork_done>: Define the label only
if USABLE_POSIX_SPAWN is defined, to avoid a compiler warning.

(cherry picked from commit a8fc08085110de00ebcbd67b5273a755a5cb8ea1)

Use posix_spawn if possible.

posix_spawn is less error-prone than vfork + execve, and can make
better use of system-specific enhancements like 'clone' on Linux.  Use
it if we don't need to configure a pseudoterminal.

Backported from commit a60053f8368e058229721f1bf1567c2b1676b239.
Unlike that commit, only define USABLE_POSIX_SPAWN on macOS, because
there posix_spawn is much faster than vfork.

Don't merge to master.

* configure.ac (HAVE_SPAWN_H, HAVE_POSIX_SPAWN)
(HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR)
(HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR_NP)
(HAVE_POSIX_SPAWNATTR_SETFLAGS, HAVE_DECL_POSIX_SPAWN_SETSID): New
configuration variables.
* src/callproc.c (USABLE_POSIX_SPAWN): New configuration macro.
(emacs_posix_spawn_init_actions)
(emacs_posix_spawn_init_attributes, emacs_posix_spawn_init): New
helper functions.
(emacs_spawn): Use posix_spawn if possible.

(cherry picked from commit a60053f8368e058229721f1bf1567c2b1676b239)

MH-E threads code: use mh-scan variables correctly

* lisp/mh-e/mh-thread.el (mh-thread-current-indentation-level)
(mh-thread-find-children): Fix off-by-one error by using
'mh-scan-field-from-start-offset' directly, as
'mh-thread-parse-scan-line' does.  Previously, these functions would
incorrectly consider the "date note" column as part of the thread
indenting.  Since that column is almost always a Space character, that
almost always worked.
(mh-thread-ancestor): Update caller.
* test/lisp/mh-e/mh-thread-tests.el: New unit tests for affected code.
* lisp/mh-e/mh-scan.el (mh-msg-num-width-to-column): Fix doc string typo.

Improve style and comments in font-related sources

* src/w32font.c (fill_in_logfont): Stylistic changes.
* src/font.h (font_property_index, font_select_entity):
Add/improve comments.

Revert accidential commit in icomplete.el

Remove Tramp's `dired-compress-file' handler, not needed anymore

* lisp/dired-aux.el (dired-check-process, dired-shell-command):
Call `dired-uncache'.
(dired-compress-file): Use `file-local-name'.

* lisp/net/tramp-adb.el (tramp-adb-file-name-handler-alist):
* lisp/net/tramp-archive.el (tramp-archive-file-name-handler-alist):
* lisp/net/tramp-crypt.el (tramp-crypt-file-name-handler-alist):
* lisp/net/tramp-gvfs.el (tramp-gvfs-file-name-handler-alist):
* lisp/net/tramp-rclone.el (tramp-rclone-file-name-handler-alist):
* lisp/net/tramp-smb.el (tramp-smb-file-name-handler-alist):
* lisp/net/tramp-sshfs.el (tramp-sshfs-file-name-handler-alist):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-file-name-handler-alist):
Remove superfluous comment.

* lisp/net/tramp-sh.el (dired-compress-file): Declare.
(tramp-sh-handle-dired-compress-file): Call real handler for
Emacs >= 29.

* lisp/net/tramp.el (tramp-file-name-for-operation): Reorder list.

* test/lisp/net/tramp-tests.el (tramp-test45-dired-compress-file)
(tramp-test45-dired-compress-dir): Adapt comment.

Fix scroll event test in handle_one_xevent

* src/xterm.c (handle_one_xevent): Test for scroll wheel button
correctly in xwidget code.

Fix font selection via :family on MS-Windows

* src/font.c (font_delete_unmatched) [HAVE_NTGUI]: Allow non-exact
matches of :weight when looking for a suitable font.  (Bug#51768)

Correct patch from 2021-11-12 on src/fileio.c

* src/fileio.c (restore_window_points): Reverse commit
974192413f8a81171b8fd28dfd5c081ce06d3dec and instead replace a < by a <=.
This ensures that if w->mpoint is at the top of the middle region being
replaced, it gets adjusted and stays at the top after the reinsertion.

Don't emit SELECT_WINDOW_EVENT when an xwidget is scrolled

* src/xterm.c (handle_one_event): Don't select xwidget window
on button event if the button pressed actually represents the
scroll wheel.

C++ Mode: Fix incoorect background fontification of <

Where c-record-found-types gets "bound" to itself, we postpone the calling of
c-fontify-new-type on possible new found types until these are confirmed by
the return from the function tentatively finding these types, for exmaple
c-forward-<>-arglist.  We check this "binding" by testing the value of
c-record-found-types.

Correct the background fontification algorithm.

* lisp/progmodes/cc-engine.el (c-record-found-types): Move the definition to
earlier in the file.
(c-add-type-1): Check additionally c-record-found-types is nil before calling
c-fontify-new-found-type.
(c-forward-<>-arglist, c-forward-type): On return from a function which
collects found types in c-record-found-types, call c-fontify-new-found-types
for each such type.

* lisp/progmodes/c-fonts.el (c-force-redisplay): Actually fontify the new
found type.
(c-fontify-new-found-type): Test for font-lock-mode being enabled.  Remove the
spurious condition on the `fontified' text property being nil before causing
c-force-redisplay to get called.

Don't create links to undefined commands in help--describe-command

* lisp/help.el (help--describe-command): Don't create links to
commands that aren't defined.