* lisp/progmodes/project.el (project-find-file): Delete recently added
'filename' arg; just use project-find-file-in.

Make the rx `or' and `seq' forms accept zero arguments to produce a
never-matching regexp and an empty string, respectively.

* lisp/emacs-lisp/rx.el: Require cl-extra.
(rx-constituents, rx-or): Permit zero args.
(rx): Amend doc string for `or' and `seq'.
* test/lisp/emacs-lisp/rx-tests.el (rx-or, rx-seq): Test the change.
* etc/NEWS (Changes in Specialized Modes and Packages): Mention the change.

This reverts commit b552fc05.
It caused a bootstrapping failure which I have yet to resolve - sorry.

For discussion, see the following threads:
https://lists.gnu.org/archive/html/emacs-devel/2019-03/msg00457.html
https://lists.gnu.org/archive/html/emacs-devel/2019-05/msg00369.html

* autogen.sh: Extend the built-in Git xfuncname pattern 'cpp' to
match preprocessor and DEFUN macros, and the 'elisp' pattern to
match cl-lib and other top-level defuns.

Thanks to Basil L. Contovounesios for additional cleanups.
For discussion, see the following thread:
https://lists.gnu.org/archive/html/emacs-devel/2019-05/msg00177.html

* lisp/delim-col.el: Use lexical-binding.

* test/lisp/delim-col-tests.el: New file.
(delim-col-tests-delimit-colummns-before-after)
(delim-col-tests-delimit-columns)
(delim-col-tests-delimit-columns-format/nil)
(delim-col-tests-delimit-columns-format/padding)
(delim-col-tests-delimit-columns-format/separator)
(delim-col-tests-delimit-columns-separator)
(delim-col-tests-delimit-columns-str-before-after)
(delim-col-tests-delimit-columns-str-separator)
(delim-col-tests-delimit-rectangle): New unit tests.

Acknowledge that when the function is called, it is always at the start of a
string, never in the middle or at the end of one.

* lisp/progmodes/cc-engine.el (c-maybe-re-mark-raw-string): Reformulate the
cond form into a `when' form, with all but the first arm of the cond
discarded.

* lisp/gnus/nnheader.el (nnheader-cancel-timer)
(nnheader-cancel-function-timers): Remove defalias calls made
redundant by subsequent define-obsolete-function-alias calls.

* lisp/w32-fns.el (w32--os-description): Fix inadvertant "o" added
to the end of the function name in the previous patch (bug#35807).

* lisp/gnus/nnheader.el (nnheader-cancel-timer)
(nnheader-cancel-function-timers): Mark as obsolete.

* lisp/gnus/nntp.el (nntp-with-open-group-function)
(nntp-async-stop): Adjust caller.

* lisp/gnus/gnus-art.el (gnus-stop-date-timer): Ditto.

* lisp/gnus/gnus-async.el (gnus-async-prefetch-next): Ditto.

* lisp/gnus/gnus-demon.el (gnus-demon-run-callback)
(gnus-demon-cancel): Ditto.

* lisp/gnus/mail-source.el (mail-source-report-new-mail): Ditto.

* lisp/gnus/nnmaildir.el (nnmaildir-request-accept-article): Ditto.

Make the rx `or' and `seq' forms accept zero arguments to produce a
never-matching regexp and an empty string, respectively.

* lisp/emacs-lisp/rx.el (rx-constituents, rx-or): Permit zero args.
(rx): Amend doc string for `or' and `seq'.
* test/lisp/emacs-lisp/rx-tests.el (rx-or, rx-seq): Test the change.
* etc/NEWS (Changes in Specialized Modes and Packages): Mention the change.

Make `auto-revert-avoid-polling' have effect in global-auto-revert-mode.
Buffers actually handled by that mode are marked with a non-nil value
of `auto-revert--global-mode'.  When global-auto-revert-mode is
entered, eligible buffers are marked in that way, and hooks are set up
to mark new buffers and take care of buffers whose file names change.
This way the existing poll-avoidance logic can be used, since the
entire set of buffers in auto-revert is known.

A new hook, `after-set-visited-file-name-hook', was added to handle
the case when the file name of a tracked buffer changes.

* lisp/autorevert.el (auto-revert-avoid-polling): Amend doc string.
(auto-revert--global-mode): New buffer-local variable.
(global-auto-revert-mode): Mark existing buffers and set up hooks when
mode is entered; do the opposite when exited.
(auto-revert--global-add-current-buffer)
(auto-revert--global-adopt-current-buffer)
(auto-revert--set-visited-file-name-advice): New functions.
(auto-revert--polled-buffers, auto-revert--need-polling-p)
(auto-revert-notify-handler)
(auto-revert-active-p): Modify logic to cover global-auto-revert-mode.
* lisp/files.el (after-set-visited-file-name-hook): New hook.
(set-visited-file-name-hook): Call new hook.
* test/lisp/autorevert-tests.el (top):  Use lexical-binding.
(auto-revert-test--write-file, auto-revert-test--buffer-string)
(auto-revert-test--wait-for, auto-revert-test--wait-for-buffer-text)
(auto-revert-test05-global-notify): New test.
* doc/lispref/hooks.texi (Standard Hooks):
Mention new hook (in a comment, since it's unclear whether it should
actually be documented here)
* etc/NEWS (Changes in Specialized Modes and Packages): Update entry.

* test/lisp/autorevert-tests.el (auto-revert--deftest-remote):
Fix typo.
(auto-revert-test02-auto-revert-deleted-file): On emba, there are
no stopped events.

Mostly, this just removes "Maintainer: emacs-devel@gnu.org" lines,
which are not that useful.  It also cleans up and regularizes a
few similar lines.

* src/keyboard.c (kbd_buffer_get_event, make_lispy_event): Use
HAVE_WINDOW_SYSTEM.

Emacs_Pix_Container is a pointer to a struct representing pixmap data
on the backend.  Emacs_Pix_Context is the context for the
bitmap/pixmap on the backend.  Only w32 currently makes this
distinction; they are otherwise the same type.

* src/dispextern.h: Remove XImagePtr in favor of
using XImage* directly. Rename XImagePtr_or_DC to Emacs_Pix_Context.
[HAVE_X_WINDOWS] Alias Emacs_Pix_Container and
Emacs_Pix_Context to XImage*.
[HAVE_NS] Alias Emacs_Pix_Container and Emacs_Pix_Context to trivial
Emacs_Pixmap definition.
[HAVE_NTGUI]: Alias Emacs_Pix_Container to XImage* and
Emacs_Pix_Context to HDC.

* src/dispextern.h:
* src/image.c: Use Emacs_Pix_Container over XImagePtr and
Emacs_Pix_Context over XImagePtr_or_DC.

The xfont backend using XChar2b in its API doesn't mean that we should
use it everywhere else.

* src/dispextern.h (glyph_string):
* src/ftcrfont.c (ftcrfont_draw):
* src/ftxfont.c (ftxfont_draw):
* src/w32term.c (w32_draw_glyphless_glyph_string_foreground):
* src/xdisp.c (init_glyph_string, get_char_face_and_encoding)
(get_glyph_face_and_encoding, get_char_glyph_code)
(fill_gstring_glyph_string, fill_stretch_glyph_string)
(normal_char_ascent_descent, gui_get_glyph_overhangs)
(compute_overhangs_and_x, gui_produce_glyphs):
* src/xfont.c (xfont_get_pcm, xfont_chars_supported, xfont_open)
(xfont_encode_char, xfont_text_extents, xfont_draw)
* src/xftfont.c (xftfont_draw):
* src/xterm.c (x_compute_glyph_string_overhangs)
(x_draw_glyphless_glyph_string_foreground): Use unsigned over XChar2b.

* src/nsgui.h:
* src/w32gui.h:
* src/xterm.h: Remove XChar2b, STORE_XCHAR2B, XCHAR2B_BYTE1, and
XCHAR2B_BYTE2 typedefs and macros.

* src/font.h (font_driver):
(ftfont_text_extents)
* src/ftcrfont.c (ftcrfont_text_extents):
* src/ftfont.c (ftfont_text_extents):
* src/macfont.m (macfont_text_extents):
* src/nsfont.m (nsfont_text_extents):
* src/w32font.h (w32_font_text_extents):
* src/font.c (xfont_text_extents):
* src/xftfont.c (xftfont_text_extents): Make code parameter const.

* src/dispextern.h [HAVE_X_WINDOWS]: Alias Emacs_GC to XGCValues.
[!HAVE_X_WINDOWS]: Define Emacs_GC, GCForeground, and GCBackground.

* src/nsgui.h:
* src/w32gui.h:Remove obsolete XGCValues, GC, GCForeground,
GCBackground, and GCFont definitions.

* src/w32fns.c (w32_make_gc): Do not set unused font field.

* src/w32term.c: Use Emacs_GC over XGCValues. Do not set unused font
field.

* src/xfaces.c: Use Emacs_GC over XGCValues and GC.

* src/dispextern.h [HAVE_X_WINDOWS]: Alias Emacs_Rectangle to
XRectangle.
[!HAVE_X_WINDOWS]: Define Emacs_Rectangle struct.
Use Emacs_Rectangle over XRectangle.

* src/frame.h (MonitorInfo):
* src/msdos.h:
* src/w32term.c:
* src/xdisp.c: Use Emacs_Rectangle over XRectangle.

* src/nsgui.h:
* src/w32gui.h: Remove old XRectangle structs.

* src/xdisp.c:
* src/nsgui.h:
* src/w32gui.h: Rename CONVERT_FROM_XRECT and CONVERT_TO_XRECT to
CONVERT_FROM_EMACS_RECT and CONVERT_TO_EMACS_RECT respectively.

* src/dispextern.h [HAVE_X_WINDOWS]: Alias Emacs_Pixmap to Pixmap.
(image, x_kill_gs_process): Use Emacs_Pixmap over Pixmap.

* src/image.c:

* src/nsgui.h:
* src/nsterm.m:
* src/termhooks.h:
* src/w32gui.h:
* src/w32term.c:
* src/w32term.h:
* src/xterm.c (x_free_pixmap): Use Emacs_Pixmap over Pixmap.

* src/w32gui.h: Remove unused typedef Bitmap.

* src/dispextern.h [HAVE_X_WINDOWS]: Define Emacs_Cursor alias. Move
the No_Cursor definition from xterm.h.
(redisplay_interface): Use Emacs_Cursor over Cursor.

* src/nsgui.h:
* src/nsterm.h:
* src/nsterm.m:
* src/w32gui.h:
* src/w32term.c:
* src/xdisp.c:
* src/xterm.c (x_define_frame_cursor): Use Emacs_Cursor over Cursor.

This avoids clashing with the XColor struct from X.

* src/dispextern [HAVE_X_WINDOWS]: Define Emacs_Color alias.
[!HAVE_X_WINDOWS]: Rename XColor compatibility struct to
Emacs_Color. Remove unused fields.

* src/gtkutil.c:
* src/gtkutil.h:
* src/image.c:
* src/nsterm.h:
* src/nsterm.m:
* src/termhooks.h:
* src/w32fns.c:
* src/w32term.c:
* src/w32term.h:
* src/xfaces.c:
* src/xfns.c:
* src/xterm.h: Use Emacs_Color over XColor outside of X-specific
sections.

* lisp/gnus/nnheader.el:
* lisp/gnus/nnmail.el: Don't autoload functions from files already
loaded.

* lisp/filenotify.el (file-notify-callback):
Comment out condition that does not seem to make any sense. All it
seems to do is allowing notifications for files on the form DIR/X/X
when we really just are watching DIR/X/Y.

in active minibuffer.  (Bug#34939)

* lisp/vc/log-view.el (log-view-diff, log-view-diff-changeset):
* doc/emacs/maintaining.texi (VC Change Log): Document behavior of
log-view-diff at the beginning and the end of the log buffer
when the region is active.  (Bug#35624)

* lisp/vc/vc-git.el (vc-git-print-log): Insert newline at the
beginning to enable the feature of diffing with the working revision.

* lisp/cus-edit.el (custom-browse-insert-prefix): Remove XEmacs
compat code and make obsolete.
(custom-group-value-create): Use `insert' directly.

* lisp/emacs-lisp/elint.el (elint-check-conditional-form): Don't
refer to function that doesn't have an if any more.

* lisp/bs.el (bs-mode-font-lock-keywords): Remove XEmacs compat code.
(bs-mode-map): Ditto.

* lisp/arc-mode.el (archive-mode-map): Remove XEmacs compat code.
(archive-summarize-files): Ditto.

* lisp/net/rfc2104.el (rfc2104-string-make-unibyte): Remove XEmacs
  compat code.

* lisp/gnus/mml.el (mml-generate-mime-1): Remove XEmacs compat code.

* lisp/progmodes/project.el (project-find-file): Add optional 'filename' arg.
(project--completing-read-strict): Ignore 'default' set to empty string.

* lisp/gnus/gnus-group.el (gnus-group-sort-flat): As
  gnus-newsrc-hashtb is now a real (unsorted) hash table, use
  gnus-group-list to maintain group sort order.
  (gnus-group-sort-selected-flat): Ditto.
* lisp/gnus/gnus-start.el (gnus-subscribe-alphabetically): Simplify
  function using seq-find.
  (gnus-subscribe-killed, gnus-subscribe-zombies): Use cl-pushnew to
  avoid adding duplicates (can happen when un/subscribing multiple
  times to one group).

* lisp/arc-mode.el (arc-insert-unibyte): Rename from
insert-unibyte, make into a function, and remove the superfluous
string-to-multibyte.  Change callers throughout the file.

* lisp/dired-x.el (dired-omit-files): Match beginning and end of
string, rather than beginning and end of line.

(hs-set-up-overlay, hs-adjust-block-beginning): Use non-nil default for
function variables, so `add-function` can be used on them.
(hs-toggle-hiding): Make it work for mouse bindings as well.
(hs-minor-mode-map): Use it for the mouse binding.
(hs-grok-mode-type): Use bound-and-true-p.
(hs-life-goes-on): Use `declare` for the debug spec.
(hs-mouse-toggle-hiding): Make it an obsolete alias.

Do not handle errors.

* lisp/window.el (windows-sharing-edge)
(window--try-to-split-window-in-direction)
(display-buffer-in-direction): New functions.
* doc/lispref/windows.texi (Buffer Display Action Functions):
Describe new action function 'display-buffer-in-direction'.
(Buffer Display Action Alists): Describe new entry 'direction'.
Amend description of 'window' entry.
* etc/NEWS: Mention 'display-buffer-in-direction' and 'direction'
and 'window' action alist entries.