* lisp/net/tramp.el (tramp-process-actions):
* lisp/net/tramp-adb.el (tramp-adb-handle-file-system-info)
(tramp-adb-handle-set-file-times)
(tramp-adb-maybe-open-connection):
* lisp/net/tramp-cmds.el (tramp-rename-files, tramp-rename-these-files)
(tramp-reporter-dump-variable):
* lisp/net/tramp-sh.el (tramp-do-file-attributes-with-stat)
(tramp-sh-handle-file-selinux-context)
(tramp-do-directory-files-and-attributes-with-stat)
(tramp-sh-handle-file-name-all-completions)
(tramp-sh-handle-write-region)
(tramp-sh-handle-file-notify-add-watch)
(tramp-sh-gvfs-monitor-dir-process-filter)
(tramp-sh-inotifywait-process-filter)
(tramp-sh-handle-file-system-info, tramp-find-executable)
(tramp-open-shell, tramp-find-shell):
* lisp/net/tramp-smb.el (tramp-smb-do-file-attributes-with-stat)
(tramp-smb-handle-file-system-info):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-file-selinux-context)
(tramp-sudoedit-handle-file-system-info): Remove superfluous
`eval-when-compile', `concat' creates the string during byte
compilation.  Reported by Mattias Engdegård <mattiase@acm.org>.

* lisp/net/tramp-adb.el (tramp-adb-prompt): Simplify.
(tramp-adb-send-command):
* lisp/net/tramp-gvfs.el (tramp-gvfs-dbus-string-to-byte-array):
Use `string-match-p'.

* lisp/net/tramp-sh.el (tramp-sunos-unames): New defconst.
(tramp-find-executable, tramp-find-shell, tramp-get-remote-stat): Use it.

* lisp/net/tramp.el (tramp-shell-prompt-pattern)
(tramp-wrong-passwd-regexp, tramp-method-regexp-alist)
(tramp-domain-regexp, tramp-host-regexp, tramp-ipv6-regexp)
(tramp-port-regexp, tramp-debug-outline-regexp)
(tramp-drop-volume-letter, tramp-parse-shostkeys)
(tramp-handle-file-name-case-insensitive-p):
* lisp/net/tramp-adb.el (tramp-adb-send-command-and-check):
* lisp/net/tramp-ftp.el (tramp-ftp-enable-ange-ftp):
* lisp/net/tramp-gvfs.el (tramp-gvfs-monitor-process-filter):
* lisp/net/tramp-sh.el (tramp-display-escape-sequence-regexp)
(tramp-device-escape-sequence-regexp):
* lisp/net/tramp-smb.el (tramp-smb-do-file-attributes-with-stat)
(tramp-smb-handle-set-file-acl, tramp-smb-read-file-entry):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-file-selinux-context):
Use character classes in regexp.

* lisp/net/tramp-adb.el (tramp-adb-ls-date-year-regexp)
(tramp-adb-ls-date-time-regexp): New defconst.
(tramp-adb-ls-date-regexp, tramp-adb-ls-toolbox-regexp)
(tramp-adb-sh-fix-ls-output): Use them.
(tramp-adb-handle-set-file-times, tramp-adb-maybe-open-connection):
Apply `eval-when-compile' on constant concat data.
(tramp-do-parse-file-attributes-with-ls):
Suppress `signal-hook-function'.
(tramp-adb--gnu-switches-to-ash): Remove unused function.
(tramp-adb-handle-set-file-modes): Qhote argument.
(tramp-adb-maybe-open-connection): Set file property rather than flush.

* lisp/net/tramp-cmds.el (tramp-rename-these-files):
Apply `eval-when-compile' on constant concat data.

* lisp/net/tramp-gvfs.el (tramp-gvfs-file-attributes)
(tramp-gvfs-file-attributes-with-gvfs-ls-regexp): Embed them in
`eval-and-compile'.
(tramp-gvfs-get-directory-attributes): Apply `eval-when-compile'
on constant concat data.

* 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-rclone.el (tramp-rclone-file-name-handler-alist):
* lisp/net/tramp-smb.el (tramp-smb-file-name-handler-alist):
Add `tramp-get-remote-gid' and 'tramp-get-remote-uid'.

* lisp/net/tramp-crypt.el (tramp-crypt-file-name-handler-alist):
Add `file-ownership-preserved-p'.
(tramp-crypt-add-directory): Check, that NAME is not quoted.
(tramp-crypt-handle-file-ownership-preserved-p): New defun.
(tramp-crypt-handle-insert-directory): Fix docstring.

* lisp/net/tramp-gvfs.el (tramp-gvfs-file-name-handler-alist):
Add `tramp-get-remote-gid' and 'tramp-get-remote-uid'.
(tramp-gvfs-handle-file-readable-p): Call `tramp-get-remote-uid'.
(tramp-gvfs-handle-get-remote-uid)
(tramp-gvfs-handle-get-remote-gid): Rename from
`tramp-gvfs-get-remote-{uid,gid}'.  Do not cache result.
(tramp-gvfs-maybe-open-connection): No special handling for remote
uid and gid.

* lisp/net/tramp-sh.el (tramp-sh-file-name-handler-alist):
Add `tramp-get-remote-gid' and 'tramp-get-remote-uid'.
(tramp-sh-handle-get-remote-uid, tramp-sh-handle-get-remote-gid):
Rename from `tramp-get-remote-{uid,gid}'.  Do not cache result.
(tramp-sh-handle-file-ownership-preserved-p): Distinguish by GROUP
when caching.

* lisp/net/tramp-sudoedit.el (tramp-sudoedit-file-name-handler-alist):
Add `tramp-get-remote-gid' and 'tramp-get-remote-uid'.
(tramp-sudoedit-handle-get-remote-uid)
(tramp-sudoedit-handle-get-remote-gid): Rename from
`tramp-sudoedit-get-remote-{uid,gid}'.  Do not cache result.
(tramp-sudoedit-handle-set-file-uid-gid)
(tramp-sudoedit-handle-write-region): Call `tramp-get-remote-uid'
and `tramp-get-remote-gid'.
(tramp-sudoedit-maybe-open-connection): No special handling for
remote uid and gid.

* lisp/net/tramp.el (tramp-file-name-for-operation):
Add `tramp-get-remote-gid' and 'tramp-get-remote-uid'.
(tramp-handle-write-region, tramp-check-cached-permissions):
Call `tramp-get-remote-uid' and `tramp-get-remote-gid'.
(tramp-get-remote-uid, tramp-get-remote-gid): New defuns.
(tramp-local-host-p): Simplify `tramp-get-remote-uid' call.

* test/lisp/net/tramp-tests.el (tramp-test17-dired-with-wildcards)
Skip if needed.

* lisp/net/tramp-adb.el (tramp-adb-handle-exec-path)
(tramp-adb-get-device):
* lisp/net/tramp-gvfs.el (tramp-gvfs-handler-askquestion):
* lisp/net/tramp-sh.el (tramp-remote-selinux-p, tramp-remote-acl-p)
(tramp-open-connection-setup-interactive-shell)
(tramp-maybe-open-connection, tramp-get-remote-path)
(tramp-get-inline-compress, tramp-get-inline-coding):
* lisp/net/tramp-smb.el (tramp-smb-get-cifs-capabilities)
(tramp-smb-get-stat-capability):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-remote-acl-p)
(tramp-sudoedit-remote-selinux-p): Cache property in main process.

* lisp/net/tramp-cache.el (tramp-cache-undefined): New defconst.
(tramp-get-hash-table, tramp-connection-property-p): Use it.
(tramp-set-connection-property, tramp-flush-connection-property)
(tramp-flush-connection-properties): Add sanity checks.
(tramp-get-file-property, tramp-set-file-property)
(tramp-get-connection-property, tramp-set-connection-property)
(tramp-dump-connection-properties): Adapt docstring.

* lisp/net/tramp-cmds.el (tramp-cleanup-connection): Delete all
processes.

* lisp/net/tramp-gvfs.el (tramp-gvfs-unmount):
Use `tramp-cleanup-connection'.

* lisp/net/tramp-sh.el (tramp-sh-handle-vc-registered):
Use `bound-and-true-p'.

* lisp/net/tramp.el (tramp-get-process): New defun.

* lisp/net/tramp-adb.el (tramp-adb-handle-set-file-times):
Implement FLAG.
(tramp-adb-handle-copy-file): Adapt `set-file-times' call.

* lisp/net/tramp-compat.el (tramp-compat-set-file-times): New defalias.

* lisp/net/tramp-gvfs.el (tramp-gvfs-handle-set-file-modes)
(tramp-gvfs-handle-set-file-times, tramp-gvfs-set-file-uid-gid):
Simplify `tramp-gvfs-url-file-name' call.

* lisp/net/tramp-sh.el (tramp-sh-handle-set-file-times): Implement FLAG.
(tramp-do-copy-or-rename-file-via-buffer)
(tramp-do-copy-or-rename-file-out-of-band): Add optional argument
OK-IF-ALREADY-EXISTS.  Adapt callees.
(tramp-do-copy-or-rename-file-via-buffer)
(tramp-do-copy-or-rename-file-directly)
(tramp-do-copy-or-rename-file-out-of-band): Adapt `set-file-times' call.

* lisp/net/tramp-smb.el (tramp-smb-handle-copy-directory)
(tramp-smb-handle-copy-file): Adapt `set-file-times' call.

* lisp/net/tramp-sudoedit.el (tramp-sudoedit-do-copy-or-rename-file):
Adapt `set-file-times' call.
(tramp-sudoedit-handle-set-file-times): Implement FLAG.

* test/lisp/net/tramp-tests.el (tramp-test22-file-times): Extend test.

This is a companion to the recent set-file-modes patch.
It adds support for a ‘nofollow’ flag to set-file-times (Bug#39773).
Like the set-file-modes patch, it needs work in the w32 port.
* admin/merge-gnulib (GNULIB_MODULES): Add futimens, utimensat.
Remove utimens.
* doc/lispref/files.texi (Changing Files):
* etc/NEWS: Mention the change.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lisp/files.el (copy-directory):
* lisp/gnus/gnus-cloud.el (gnus-cloud-replace-file):
* lisp/net/tramp-adb.el (tramp-adb-handle-copy-file):
* lisp/net/tramp-smb.el (tramp-smb-handle-copy-file):
* lisp/tar-mode.el (tar-copy):
* test/lisp/filenotify-tests.el (file-notify-test03-events):
* test/lisp/files-tests.el:
(files-tests-file-name-non-special-set-file-times):
* test/lisp/net/tramp-tests.el (tramp-test22-file-times):
When setting file times, avoid following symbolic links
when the file is not supposed to be a symbolic link.
* lib/futimens.c, lib/utimensat.c, m4/futimens.m4, m4/utimensat.m4:
New files, copied from Gnulib.
* lisp/gnus/gnus-cloud.el (gnus-cloud-replace-file):
When creating a file that is not supposed to exist already,
use the excl flag to check this.
* lisp/net/tramp-adb.el (tramp-adb-handle-set-file-times):
* lisp/net/tramp-sh.el (tramp-sh-handle-set-file-times):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-set-file-times):
Accept an optional FLAG arg that is currently ignored,
and add a FIXME comment for it.
* lisp/net/tramp-gvfs.el (tramp-gvfs-handle-set-file-times):
* src/fileio.c (Fset_file_times):
Support an optional FLAG arg.
* src/fileio.c (Fcopy_file): Use futimens instead of set_file_times,
as it’s simpler and is a POSIX API.
* src/sysdep.c (set_file_times): Move from here ...
* src/w32.c (set_file_times): ... to here, and make it static,
since it is now used only in w32.c.  Presumably w32.c should also
add support for futimens and utimensat (the POSIX APIs, which
Emacs now uses) and it can remove fdutimens (the Gnulib API,
which Emacs no longer uses).

* lisp/net/tramp-adb.el (tramp-adb-handle-file-local-copy):
Do not use 'nofollow.
(tramp-adb-handle-set-file-modes):
* lisp/net/tramp-smb.el (tramp-smb-handle-set-file-modes):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-set-file-modes):
* lisp/net/tramp-sh.el (tramp-sh-handle-set-file-modes):
Handle FLAG properly.
(tramp-get-remote-chmod-h): Adapt implementation.

* test/lisp/net/tramp-tests.el (tramp-get-remote-chmod-h): Declare.
(tramp--test-ignore-make-symbolic-link-error): Revert last change.
(tramp-test20-file-modes): Adapt test.

* lisp/net/tramp-adb.el (tramp-adb-handle-file-local-copy): Do not use
'nofollow for temporary files.  Use `tramp-compat-set-file-modes'.
(tramp-adb-handle-write-region): Do not use 'nofollow for
temporary files.
(tramp-adb-handle-set-file-modes): Implement FLAG.

* lisp/net/tramp-compat.el (tramp-compat-file-modes)
(tramp-compat-set-file-modes): New defaliases.

* lisp/net/tramp-gvfs.el (tramp-gvfs-handle-set-file-modes):
Make explicit check (eq flag 'nofollow).

* lisp/net/tramp-sh.el (tramp-sh-handle-set-file-modes): Implement FLAG.
(tramp-do-copy-or-rename-file-directly)
(tramp-sh-handle-file-local-copy, tramp-sh-handle-write-region):
Do not use 'nofollow for temporary files.
(tramp-get-remote-chmod-h): New defun.

* lisp/net/tramp-smb.el (tramp-smb-handle-set-file-modes):
Implement FLAG.

* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-set-file-modes):
Implement FLAG.
(tramp-sudoedit-handle-write-region): Use `tramp-compat-set-file-modes'.

* lisp/net/tramp.el (tramp-default-file-modes): Optional argument FLAG.
(tramp-handle-file-modes): Use `file-truename' instead of
`file-chase-links'.  The latter function does not work for remote
file names.
(tramp-handle-write-region): Call `tramp-default-file-modes' with
'nofollow if needed.  Do not use 'nofollow for temporary files.

* test/lisp/net/tramp-tests.el
(tramp--test-ignore-make-symbolic-link-error): Check also for
"Cannot chmod .* with nofollow flag" error.
(tramp-test20-file-modes): Extend test.
(tramp--test-emacs28-p): New defun.

This avoids some race conditions (Bug#39683).  E.g., if some other
program changes a file to a symlink between the time Emacs creates
the file and the time it changes the file’s permissions, using the
new flag prevents Emacs from inadvertently changing the
permissions of a victim in some completely unrelated directory.
* admin/merge-gnulib (GNULIB_MODULES): Add fchmodat.
* doc/lispref/files.texi (Testing Accessibility, Changing Files):
* doc/lispref/os.texi (File Notifications):
* etc/NEWS:
Adjust documentation accordingly.
* lib/chmodat.c, lib/fchmodat.c, lib/lchmod.c, m4/fchmodat.m4:
* m4/lchmod.m4: New files, copied from Gnulib.
* lib/gnulib.mk.in: Regenerate.
* lisp/dired-aux.el (dired-do-chmod):
* lisp/doc-view.el (doc-view-make-safe-dir):
* lisp/emacs-lisp/autoload.el (autoload--save-buffer):
* lisp/emacs-lisp/bytecomp.el (byte-compile-file):
* lisp/eshell/em-pred.el (eshell-pred-file-mode):
* lisp/files.el (backup-buffer-copy, copy-directory):
* lisp/gnus/mail-source.el (mail-source-movemail):
* lisp/gnus/mm-decode.el (mm-display-external):
* lisp/gnus/nnmail.el (nnmail-write-region):
* lisp/net/tramp-adb.el (tramp-adb-handle-file-local-copy)
(tramp-adb-handle-write-region):
* lisp/net/tramp-sh.el (tramp-do-copy-or-rename-file-directly):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-write-region):
* lisp/net/tramp.el (tramp-handle-write-region)
(tramp-make-tramp-temp-file):
* lisp/server.el (server-ensure-safe-dir):
* lisp/url/url-util.el (url-make-private-file):
When getting or setting file modes, avoid following symbolic links
when the file is not supposed to be a symbolic link.
* lisp/doc-view.el (doc-view-make-safe-dir):
Omit no-longer-needed separate symlink test.
* lisp/gnus/gnus-util.el (gnus-set-file-modes):
* lisp/net/tramp.el (tramp-handle-file-modes):
* lisp/net/tramp-gvfs.el (tramp-gvfs-handle-set-file-modes):
* src/fileio.c (symlink_nofollow_flag): New function.
(Ffile_modes, Fset_file_modes):
Support an optional FLAG arg.  All C callers changed.
* lisp/net/ange-ftp.el (ange-ftp-set-file-modes):
* lisp/net/tramp-adb.el (tramp-adb-handle-set-file-modes):
* lisp/net/tramp-sh.el (tramp-sh-handle-set-file-modes):
* lisp/net/tramp-smb.el (tramp-smb-handle-set-file-modes):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-set-file-modes):
Accept an optional FLAG arg that is currently ignored,
and add a FIXME comment for it.
* m4/gnulib-comp.m4: Regenerate.