* src/fileio.c (file_name_directory): New static function,
broken out of Ffile_name_directory.
(file_name_case_insensitive_err, Ffile_writable_p, Fdo_auto_save):
Use it.
(file_name_case_insensitive_err): Rename from
file_name_case_insensitive_p.  Accept an unencoded Lisp_Object
rather than an encoded char *, so that platforms other than
Cygwin and macOS need not encode the file name.  Return an int
-1, 0, errno rather than a bool (setting errno if false),
so that the caller can distinguish an error from false.
All callers changed.
(Ffile_name_case_insensitive_p): Don’t issue system calls on
platforms other than Cygwin and macOS.  Fix bug that broke the
attempt to move up the filesystem tree (it moved up only one
level).

* src/fileio.c (time_error_value): EACCES means the file
timestamp is unknown, not that the file does not exist.

* src/callproc.c (init_callproc): Diagnose I/O errors,
access errors, etc. for the game directory.
* src/charset.c (init_charset): Improve quality of diagnostic
when the charsets directory has I/O errors, access errors, etc.

30c4f35a (origin/emacs-26) query-replace-regexp undo: Update next-repl...
c596be08 Amend the menu caption for page "Display Property" in the Eli...
13b95100 Add description of chinese-sisheng

The following commit was skipped:

7e527af7 Fix non-deterministic process test

8e420c09 Clarify the use of left/right-margin-width in determining cur...

The following commit was skipped:

0c3fc71d ; Bump Emacs version to 26.3.50

* test/lisp/shadowfile-tests.el (top): Use truename of
`temporary-file-directory' and
`shadow-test-remote-temporary-file-directory'.  (Bug#37202)
(shadow-test08-shadow-todo, shadow-test09-shadow-copy-files):
Do not bind `shadow-test-remote-temporary-file-directory'.

* lisp/wid-browse.el (widget-browse-at): Also look for the real-field
property when detecting a field (bug#37199).

* lisp/vc/vc-svn.el: (vc-svn-ignore-completion-table) Ignore buffer
contents, if exit status is not 0.  Split buffer by lines (bug#37214).

* lisp/vc/vc.el: (vc-default-ignore) Treat FILE parameter as relative
to DIRECTORY parameter.  Construct a file-path relative to directory
of ignore file.  When removing, use properly anchored regexp.  Remove
entire line, not just the match (bug#37217).

* lisp/vc/vc-dir.el: (vc-dir-ignore) With prefix argument, ignore all
marked files (bug#37240).

This reverts commit 6fe66134.

The alternate editor may be Emacs, which is useful when you want to eval something in an existing Emacs (if it exists), or in a new Emacs if there's no server running.

* src/fileio.c (file_name_case_insensitive_p):
Don’t assume ‘long int’ fits in ‘int’.

* src/alloc.c (garbage_collect): Don’t accumulate rounding
errors when computing gc-elapsed.

* doc/lispref/internals.texi (Garbage Collection), etc/NEWS:
Warn that control over GC is only approximate.

* doc/misc/gnus.texi (Picons): Fix instructions for installing
picons on Debian (bug#37247).

Copyright-paperwork-exempt: yes

* lisp/net/eww.el (eww-submit): Ignore file inputs with no
associated file name (bug#36520).

* lisp/net/shr.el (svg--wrap-svg): Add a default foreground colour
to SVG images (bug#37159).  This helps with images like the ones
in https://en.wikipedia.org/wiki/Banach_fixed-point_theorem that
specify no foreground or background colours.
(shr-parse-image-data): Use it.

* lisp/net/eww.el (eww--preprocess-html): New function (bug#37009)
to be more lenient with invalid HTML and translate common invalid
HTML like "a <= b" into "a &lt;= b" to be more liberal in what we
accept before parsing.
(eww-display-html): Use it.
(eww-readable): Ditto.

* lisp/wid-edit.el (widget-specify-insert): Add a debug
declaration (bug#37368).

Copyright-paperwork-exempt: yes

* lisp/play/gamegrid.el (gamegrid-add-score): Add 'reverse' parameter.
(gamegrid-add-score-with-update-game-score): Add 'reverse' parameter.
(gamegrid-add-score-with-update-game-score-1): Add 'reverse'
parameter.  Pass on "-r" argument to update-game-score.
(gamegrid-add-score-insecure): Add 'reverse' parameter, reverse scores
when it's non-nil.  (Bug#36867)

* etc/NEWS: Announce the change.

The old calculation relied on a hodgpodge of partly updated GC
stats to find a number to multiply gc-cons-percentage by.
The new one counts data found by the previous GC, plus half of
the data allocated since then; this is more systematic albeit
still ad hoc.
* src/alloc.c (consing_until_gc, gc_threshold, consing_threshold):
Now EMACS_INT, not intmax_t.
(HI_THRESHOLD): New macro.
(tally_consing): New function.
(make_interval, allocate_string, allocate_string_data)
(make_float, free_cons, allocate_vectorlike, Fmake_symbol): Use it.
(allow_garbage_collection, inhibit_garbage_collection)
(consing_threshold, garbage_collect):
Use HI_THRESHOLD rather than INTMAX_MAX.
(consing_threshold): New arg SINCE_GC.  All callers changed.
(bump_consing_until_gc): Return new consing_until_gc, instead of
nil.  All callers changed.  Don’t worry about overflow since we
now saturate at HI_THRESHOLD.  Guess that half of
recently-allocated objects are still alive, instead of relying on
the previous (even less-accurate) hodgepodge.
(maybe_garbage_collect): New function.
(garbage_collect): Work even if a finalizer disables or enables
memory profiling.  Do not use malloc_probe if GC reclaimed nothing.
* src/lisp.h (maybe_gc): Call maybe_garbage_collect instead
of garbage_collect.

* src/alloc.c (make_interval, allocate_string, make_float)
(free_cons, Fcons, setup_on_free_list)
(allocate_vector_from_block, Fmake_symbol):
Do not update gcstat, since it is for statistics from the most
recent GC, not for a partially-updated hodgepodge.
(sweep_vectors): Update gcstat, since setup_on_free_list
no longer does.
(garbage_collect_1): Rename to garbage_collect and adopt its API.
Remove the old garbage_collect, which is no longer needed.
All callers changed.

There are only a few users of print-number-table, and none of them use
it when print-circle is nil.  A couple of them used to.  print_object
was changed in 2012-04-20 "* src/print.c (print_preprocess): Only
check print_depth if print-circle is nil".
byte-compile-output-docform which uses print-number-table binds
print-circle to t before printing unless
byte-compile-disable-print-circle is set, but that variable has been
marked obsolete since 24.1.

* src/print.c (print_preprocess): Assert Vprint_circle is non-nil.
Remove code handling the case when Vprint_circle is nil.
(print, Fprint_preprocess): Don't call print_preprocess unless
Vprint_circle is non-nil.
(print_object): Remove comment referencing removed code in
print_preprocess.

* test/lisp/emacs-lisp/cl-print-tests.el
(cl-print--test, cl-print-tests-1, cl-print-tests-2)
(cl-print-tests-3, cl-print-tests-4, cl-print-tests-5)
(cl-print-tests-strings, cl-print-circle, cl-print-circle-2):
Remove.
* test/src/print-tests.el (print-tests--prin1-to-string): New
alias.
(print-tests--deftest): New macro.
(print-hex-backslash, print-read-roundtrip, print-bignum): Define with
print-tests--deftest and use print-tests--prin1-to-string.
(print-tests--prints-with-charset-p): Use
print-tests--prin1-to-string.
(print-tests--print-charset-text-property-nil)
(print-tests--print-charset-text-property-t)
(print-tests--print-charset-text-property-default): Define with
print-tests--deftest.
(print-tests-print-gensym)
(print-tests-continuous-numbering, print-tests-1, print-tests-2)
(print-tests-3, print-tests-4, print-tests-5)
(print-tests-strings, print-circle, print-circle-2): New tests.
(print--test, print-tests-struct): New cl-defstructs.

cl-prin1 prints all its punctuation by passing strings to prin1.  When
print-circle was set, print_preprocess was creating a new hash table
for each string, causing excessive garbage collection when printing
large Lisp objects with cl-prin1.

* src/print.c (print_number_index): Fix typo in comment above.
(PRINT_CIRCLE_CANDIDATE_P): Don't create print_number_table
for top-level strings with no properties, except when
print_continuous_numbering is on.

* lisp/emacs-lisp/cl-print.el (cl-print-to-string-with-limit): Reduce
print-level and print-length more quickly when the structure being
printed is very large.

* lisp/emacs-lisp/backtrace.el (backtrace-view): Mention
:print-gensym in docstring.
(backtrace-mode-map): Add keyboard binding for
backtrace-toggle-print-gensym.  Add menu entries for
backtrace-toggle-print-circle and backtrace-toggle-print-gensym.
(backtrace--with-output-variables): Bind print-gensym with value
of :print-gensym found in view plist.
(backtrace-toggle-print-circle): Remove description of
implementation details from docstring.
(backtrace-toggle-print-gensym): New command.
(backtrace--toggle-feature): Add echo area message describing result
of command.

* test/lisp/emacs-lisp/backtrace-tests.el
(backtrace-tests--print-circle): New test.

* doc/lispref/debugging.texi (Backtraces): Document keyboard
binding for backtrace-toggle-print-gensym.

* lisp/mail/feedmail.el (top-level): Remove outdated comment.
(feedmail-run-the-queue): Remove leftover XEmacs compat code.
(feedmail-nuke-bcc): Doc fix.

* lisp/emulation/viper.el (top-level, viper-mode)
* lisp/net/rfc2104.el (top-level): Doc fix.

* lisp/textmodes/table.el (top-level): Remove obsolete todo.

* lisp/select.el (gui--selection-value-internal): Change comment into
doc string.  (Bug#25528)