* lisp/progmodes/gdb-mi.el (gdb-control-commands-regexp): Add
support for "explore", "explore value", and "explore type".
Allow more than one word after control commands.
(gdb-gdb): Decrease gdb-control-level when we get the "(gdb)"
prompt, which signals that "explore" exited.  (Bug#40250)

* lisp/faces.el (face-spec-choose): Reverse order of 'defaults'
and 'result' when generating attribute list, so that the spec for
'default' "terminal class" is indeed overridden by the actual
class's spec, per the documentation.  (Bug#40336)

(archive--file-desc): Remove `case-fiddled`.
Change all subtypes's constructors as their callers accordingly.
(archive--file-desc-case-fiddled): New function.
(archive-int-to-mode): Accept a nil input.
Make all callers take advantage of it.
(archive-arc-rename-entry): Use `make-string`.
(archive-zip--file-desc): Change `pos+len` field into `pos` field.
(archive-zip-chmod-entry): Simplify accordingly.
(archive-zip-summarize): Don't bother with `lheader` which was not used.
(archive-zoo--file-desc): Delete struct; use archive--file-desc instead.
(archive-7z--file-desc): Remove `user` and `group` fields.
Adjust constructor and its caller.
(archive-ar-summarize): Use `archive-int-to-mode`.

(archive--file-desc, archive--file-summary, archive-arc--file-desc)
(archive-lzh--file-desc, archive-zip--file-desc)
(archive-zoo--file-desc, archive-rar--file-desc)
(archive-7z--file-desc, archive-ar--file-desc): New structs.

(archive-get-descr, archive-mode, archive-summarize-files)
(archive-maybe-copy, archive-extract, archive-*-write-file-member)
(archive-expunge, archive-arc-summarize, archive-arc-rename-entry)
(archive-lzh-summarize, archive-lzh-rename-entry, archive-lzh-ogm)
(archive-zip-summarize, archive-zip-write-file-member)
(archive-zip-chmod-entry, archive-zoo-summarize)
(archive-rar-summarize, archive-7z-summarize, archive-ar-summarize)
(archive-ar-write-file-member): Use struct constructors and accessors
instead of `vector` and `aref`.

(archive-calc-mode): Remove `error` arg which was always non-nil;
adjust all callers.
Rewrite using `string-to-number` and `file-modes-symbolic-to-number`.

* lisp/progmodes/cc-engine.el (c-looking-at-or-maybe-in-bracelist): Add code
to recognize a literal brace expression following an array declaration for
C++.
(c-looking-at-inexpr-block): Replace c-symbol-chars with c-symbol-char-key,
fixing a coding error.

(archive-ar--name): New funtion, extracted from `archive-ar-summarize`.
(archive-ar-extract): Use it.
(archive-ar-summarize): Use it.  Put the extname in the slot 0 of the
desc vectors.

(archive-arc, archive-lzh, archive-zip, archive-zoo): Move them
to their corresponding defcustom.
(archive-7z): New group, that used to be missing.

(arc-insert-unibyte): Simplify.
(archive--mode-revert): Rename from `archive-mode-revert` and adjust
for use as an :around advice.
(archive-mode): Use setq-local.  Use `add-function` to hook into
`revert-buffer-function`.
(archive-summarize): Don't use `set` on a hook.

* lisp/net/dns.el (dns-set-servers): Set dns-servers to nil when we
don't find any DNS servers with nslookup.  Add support for IPv6
servers.  (Bug#40248).
(dns-make-network-process): Check for datagram process support before
creating a datagram process.
(dns-query): Return nil if dns-servers is nil.

The handling of :coding nil was different between
make-{network,serial}-process and make-{pipe}process.  Now they all
handle :coding nil as if :coding had not been specified.

* process.c (Fmake_serial_process)
(set_network_socket_coding_system): Use plist-get to check if
:coding has been specified instead of plist-member, to ensure that
":coding nil" does not override coding-system-for-{read,write}.

* network-stream-tests.el (check-network-process-coding-system-bind)
(check-network-process-coding-system-no-override)
(check-network-process-coding-system-override): New tests.

* etc/NEWS: Describe change in make-network-process and
make-serial-process :coding behavior.

* lisp/textmodes/texinfo.el (texinfo-texi2dvi-options): New
defcustom.
(texinfo-tex-buffer): Take 'tex-start-options' from
'texinfo-texi2dvi-options'.  (Bug#40001)

* etc/NEWS: Mention the new option.

Copyright-paperwork-exempt: yes

* lisp/emacs-lisp/find-func.el (read-library-name): Add autoload
cookie.
* lisp/files.el (load-library)
* lisp/subr.el (locate-library): Use 'read-library-name' when called
interactively. (bug#6652 bug#6679)

* lisp/play/gomoku.el (gomoku-mode-map): Bind cursor motion keys
to gomoku-specific commands.
(gomoku-point-x, gomoku-move-right, gomoku-move-left): New
commands.
(gomoku--intangible, gomoku-move-ne, gomoku-move-se)
(gomoku-move-nw, gomoku-move-sw): Call gomoku-move-left and
gomoku-move-right instead of forward-char and backward-char.
(Bug#40169)

* etc/NEWS: Call out the changes.

* lisp/calendar/time-date.el (date-days-in-month): Improve the
error message text and make sure MONTH is a number.  (Bug#40217)

* lisp/calendar/time-date.el (date-days-in-month): Add test for
month validity; signal an error if it isn't.  (Bug#40217)
* test/lisp/calendar/time-date-tests.el (test-days-in-month): Add
a test for the new error.

* lisp/eshell/em-dirs.el (eshell-dirs-initialize): Add INSIDE_EMACS
variable to buffer-local value of eshell-variable-aliases-alist.
(eshell-inside-emacs): Add new constant used for INSIDE_EMACS.
* lisp/eshell/esh-var.el (eshell-variable-aliases-list): Update doc
string; remove mention of eshell-user-aliases-list and explain that
variables can optionally be copied to subprocesses' environments.
* test/lisp/eshell/eshell-tests.el (eshell-test/inside-emacs-var): Add
test for the INSIDE_EMACS variable.
* etc/NEWS: Announce changes.

* lisp/vc/vc-dir.el (vc-dir-mark-state-files): New function.
(vc-dir-mark-registered-files)
(vc-dir-mark-unregistered-files): New commands.
(vc-dir-mode-map): Bind vc-dir-mark-registered-files to '* r'.
(vc-dir-menu-map): Add menu entries for
vc-dir-mark-registered-files and vc-dir-mark-unregistered-files.

Separate values for box line width and height and allow both to be
negative which makes the visual width and height of the boxed string
unchanged (Bug#13011).

* doc/lispref/display.texi (Face Attributes): Modify :box attribute
description to reflect the new possibilities.
* lisp/cus-face.el (custom-face-attributes): Set box attribute to get
two integer to set vertical and horizontal width and modify pre-filter
to accept dotted list of two int as valid box attribute.
* src/dispextern.h (face): Use two int for box horizontal and vertical
line width.

* src/nsfont.m (nsfont_draw): Use new face attributes.
* src/nsterm.m (ns_draw_box, ns_draw_relief): Support separated
horizontal and vertical box line width.
(ns_dumpglyphs_box_or_relief, ns_maybe_dumpglyphs_background)
(ns_dumpglyphs_image, ns_draw_glyph_string_foreground)
(ns_draw_composite_glyph_string_foreground): Use new face attributes.

* src/w32term.c (w32_draw_box_rect, w32_draw_relief_rect): Support
separated horizontal and vertical box line width.
(x_draw_glyph_string_background, x_draw_glyph_string_foreground)
(x_draw_composite_glyph_string_foreground)
(x_draw_glyphless_glyph_string_foreground, x_draw_glyph_string_box)
(x_draw_image_foreground, x_draw_image_relief)
(w32_draw_image_foreground_1, x_draw_image_glyph_string): Use new face
attributes.

* src/xfaces.c (Sinternal_set_lisp_face_attribute, realize_x_face):
Accept box attribute as a list of two ints.

* src/xdisp.c (estimate_mode_line_height, produce_image_glyph)
(produce_xwidget_glyph, x_produce_glyphs): Use new face attributes.
* src/xterm.c (x_draw_box_rect, x_draw_relief_rect): Support separated
horizontal and vertical box line width.
(x_draw_glyph_string_background, x_draw_glyph_string_foreground)
(x_draw_composite_glyph_string_foreground)
(x_draw_glyphless_glyph_string_foreground, x_draw_glyph_string_box)
(x_draw_image_foreground, x_draw_image_relief, x_draw_image_foreground_1)
(x_draw_image_glyph_string): Use new face attributes.

* src/pdumper.c (dump_buffer): Update hash of struct buffer.

* lisp/net/trampver.el (tramp-repository-branch)
(tramp-repository-version): Bind `debug-on-error' to nil.

* etc/compilation.txt: Add doc and example.
* lisp/progmodes/compile.el (compilation-error-regexp-alist-alist):
Add javac rule.
(compilation-parse-errors): Fix file/line/col test, so that
lambda/closure (which are valid values) don't match.
* test/lisp/progmodes/compile-tests.el
(compile-tests--test-regexps-data, compile-test-error-regexps): Add
test.

* src/alloc.c (enum mem_type): Remove MEM_TYPE_BUFFER.
(allocate_buffer): Allocate like any other pseudovector.
Don't register on `all_buffers` any more.
(live_buffer_holding, live_buffer_p): Delete functions.
(mark_maybe_object, valid_lisp_object_p): Don't pay attention to
MEM_TYPE_BUFFER any more.
(garbage_collect): Only compact the live buffers.
(mark_buffer): Mark the undo_list of dead buffers here.
(mark_object): Buffers are normal pseudovectors now.
(sweep_buffers): Don't do the actual sweep here, just cleanup the
markers and only for live buffers.

* src/buffer.c (all_buffers): Remove variable.
(Fkill_buffer): Don't check indirect dead buffers.
Set the undo_list before we remove ourselves from the list of live buffers.
(Fbuffer_swap_text, Fset_buffer_multibyte): Don't check indirect dead
buffers.
(init_buffer_once): Don't set `all_buffers`.
(init_buffer): Don't map new memory for dead buffers.

* src/buffer.h (struct buffer): Remove `next` field.
(FOR_EACH_BUFFER): Remove macro.

* src/pdumper.c (dump_buffer): Don't dump the `next` field.

Suggested by Eric Michael Timmons <etimmons@mit.edu>.
* lisp/fileloop.el (fileloop-initialize-replace): Save the
match-beginning position in a variable instead of the buffer's point.
The point may be changed by the time perform-replace is called, e.g.,
due to switch-to-buffer-preserve-window-point.

* test/lisp/net/tramp-tests.el (tramp-test29-start-file-process)
(tramp-test30-make-process, tramp-test33-environment-variables):
Expect failure on hydra.nixos.org, since March 29 Tramp cache changes.

* lisp/minibuffer.el (minibuffer-completion-help): Run
display-completion-list in the original buffer mainbuf
to allow completion-setup-function set completion-reference-buffer to it.

Fixes bug#40332

c6e0981b (origin/emacs-27) * lisp/image/image-converter.el: Fix cus...
461bd9cc Fix url-cookie.el for lexical binding
f3ccfb19 ; * src/decompress.c: Fix comment style.
1af03e7e ; * src/xfaces.c (syms_of_xfaces): Fix wording and typo.
93945fcd ; * test/lisp/calc/calc-tests.el: Fix mistake in last commit
ee47e00f Don't suggest setting face-remapping-alist to a literal (B...
c2b8ce44 Calc: don't treat nil as an integer (bug#40155)
e1f0e089 * lisp/files.el (directory-files-recursively): Doc fix.  (...
02b38203 Document how to disable Tramp file archives

The following commit was skipped:

4860530f Don't add repeated xlmns:xlink declarations in svg-create

8db6b432 Calc: Declare dynamic variable bound in lexbind code (bug#...

* src/buffer.c (init_buffer) [USE_MMAP_FOR_BUFFERS]: Remove the
assertion that ensured all buffers in pdumped Emacs have non-NULL
pointer to buffer text.  That was false when Emacs was pdumped
with killed buffer(s) in the all_buffers linked list.  See
https://lists.gnu.org/archive/html/emacs-devel/2020-03/msg00800.html
for more details.

* lisp/image/image-converter.el (image-convert-p): Update
image-converter-regexp when image-converter was customized (bug#39994).

* doc/lispref/display.texi (Temporary Displays):
Remove defmac with-displayed-buffer-window.

* doc/lispref/windows.texi (Buffer Display Action Alists):
Add body-function.

* lisp/window.el (with-displayed-buffer-window): Declare macro obsolete.
(window--display-buffer): Call 'body-function' after displaying the buffer.

* lisp/dired.el (dired-mark-pop-up):
* lisp/files.el (save-buffers-kill-emacs):
* lisp/minibuffer.el (minibuffer-completion-help):
Replace with-displayed-buffer-window with with-current-buffer-window
and add action alist entry 'body-function' with former macro body.

* lisp/dired-aux.el (dired-vc-next-action): New command.
(dired-vc-deduce-fileset): Rename from vc-dired-deduce-fileset in vc.el.

* lisp/dired.el (dired-mode-map): Remap vc-next-action to
dired-vc-next-action.

* lisp/vc/vc-dir.el (vc-dir-mark-files): New function.
(vc-dir-refresh): Run hook vc-dir-refresh-hook.

* lisp/vc/vc.el (vc-deduce-fileset): Rename arg 'observer' to
'not-state-changing' and document it in docstring.
(vc-dired-deduce-fileset): Rename to dired-vc-deduce-fileset in dired-aux.el.

* lisp/cedet/ede.el (ede-turn-on-hook, ede-minor-mode):
* lisp/desktop.el (desktop-minor-mode-table): Rename the long ago
obsolete vc-dired-mode to vc-dir-mode.

* lisp/url/url-cookie.el (url-cookie-handle-set-cookie): Use setq
instead of set to modify lexical binding.

* configure.ac (LN_S_FILEONLY): Set to "/bin/ln" for MinGW
unconditionally.