Dired: Handle posix wildcards in directory part

Allow Dired to handle calls like
\(dired \"~/foo/*/*.el\"), that is, with wildcards within
the directory part of the file argument (Bug#27631).
* lisp/files.el (insert-directory-wildcard-in-dir-p): New predicate.
(insert-directory-clean): New defun extracted from insert-directory.
(insert-directory)
* lisp/dired.el (dired-internal-noselect)
(dired-insert-directory): Use the new predicate; when it's true,
handle the directory wildcards with a shell call.
* lisp/eshell/em-ls.el (eshell-ls-use-in-dired): Add/remove both advices.
(eshell-ls-unload-hook): New defun.  Use it in
eshell-ls-unload-hook instead of an anonymous function.
(eshell-ls--dired)
* lisp/ls-lisp.el (ls-lisp--dired):
Advice dired to handle wildcards in the directory part with both
eshell-ls and ls-lisp.
* etc/NEWS: Announce it.
* doc/emacs/dired.texi (Dired Enter): Update manual.
* test/lisp/dired-tests.el (dired-test-bug27631): Add test.

* lisp/find-lisp.el: Enable lexical binding

* lisp/find-dired.el: Enable lexical binding

* lisp/kmacro.el: Use lexical binding.

Use lexical-binding in dired-aux.el

* lisp/dired.el: Use lexical binding.
(dired-do-shell-command): Remove unused bindings.

* lisp/ido.el: Use lexical binding.

* lisp/whitespace.el: Use lexical binding.

artist.el: Avoid error with keyboard command invocation

* lisp/textmodes/artist.el (artist-mouse-choose-operation):
Call x-popup-menu with t instead of last-nonmenu-event as the
value of the position argument; this allows invoking the
command from the keyboard without raising an error (bug#27819).

Preserve point under 'dired-auto-revert-buffer' (third case)

* lisp/files.el (find-file): Use pop-to-buffer-same-window
instead of switch-to-buffer.  This preserves Dired window
point when dired-auto-revert-buffer is non-nil.  (Bug#27243)

* test/lisp/dired-tests.el (dired-test-bug27243-01)
(dired-test-bug27243-02, dired-test-bug27243-03): New tests.
The first two replace a previous test that combined them; that
test intermittently fails in the Hydra build system, so maybe
separating the two cases will help locate the point of
failure.  The third test involves find-file but is here
because it, like the others, is testing the effect of
dired-auto-revert-buffer.

Do not unset user key remaps in dired-x

* lisp/dired-x.el (dired-x-bind-find-file): Don't map any keys if user
sets dired-x-hands-off-my-keys.  (Bug#27828)

Copyright-paperwork-exempt: yes

Improve documentation of 'occur'

* doc/emacs/search.texi (Other Repeating Search):
* lisp/replace.el (occur): Make the documentation of 'occur' be
more accurate when matches overlap.  (Bug#27818)

Minor copyedits of comments in faces.el

* lisp/faces.el (face-font-family-alternatives): More info about
requirements from "Monospace Serif".

; Revert "; * .gitignore: Add .deps/."

This reverts commit f1ed31a8f5c6f19aa5e119e670533241c6375945.

Do not worry about paxctl on newer NetBSD

Problem reported privately by Thomas Klausner.
* configure.ac (emacs_uname_r): New var.  Use it to avoid paxctl
on newer NetBSD platforms, where it is not needed.  Also use it to
simplify Cygwin diagnostic.

Clarify documentation of ':inherit' face attribute

* doc/lispref/display.texi (Face Attributes): Document the special
treatment of 'unspecified' in the ':inherit' attribute.

* lisp/password-cache.el (password-data): Use a hash-table

* lisp/auth-source.el (auth-source-magic): Remove.
(auth-source-forget+, auth-source-forget-all-cached): Adjust to new
format of password-data.
(auth-source-format-cache-entry): Just use a cons.

(password-cache-remove, password-cache-add, password-reset)
(password-read-from-cache, password-in-cache-p): Adjust accordingly.

Fixes: bug#26699

* lisp/subr.el (define-symbol-prop): New function

(symbol-file): Make it find symbol property definitions.

* lisp/emacs-lisp/pcase.el (pcase-defmacro):
* lisp/emacs-lisp/ert.el (ert-set-test): Use it instead of `put'.
(ert-describe-test): Adjust call to symbol-file accordingly.

* lisp/subr.el (method-files): Move function to cl-generic.el

* lisp/emacs-lisp/cl-generic.el (cl-generic-p): New function.
(cl--generic-method-files): New function, moved from subr.el.
* lisp/emacs-lisp/edebug.el (edebug-instrument-function): Use them.
* test/lisp/emacs-lisp/cl-generic-tests.el:
* test/lisp/subr-tests.el: Move and adjust method-files tests accordingly.

Preserve this-command-keys across recursive-edit invocations

* src/minibuf.c (read_minibuf, read_minibuf_unwind): Save and
restore this-command-keys, to preserve it across recursive-edit.
(Bug#27470)

; * .gitignore: Add .deps/.

Improve doc string of 'locate-dominating-file'

* lisp/files.el (locate-dominating-file): Doc fix.  (Bug#27798)

New commands 'apropos-local-variable', 'apropos-local-value'

* lisp/apropos.el (apropos-local-variable, apropos-local-value):
New functions.  (Bug#27424)

* doc/emacs/help.texi (Apropos): Document 'apropos-local-variable'
and 'apropos-local-value'.
* etc/NEWS: Mention the new commands.

* lisp/loadhist.el (unload-feature): Remove ad-hoc ELP code

* lisp/emacs-lisp/elp.el (loadhist-unload-element): Un-instrument functions.

Fix C++ class initializers not always being fontified at mode start.

The problem here happened when an "outer list" of declarations moved beyond an
"inner list" containing class initializers.  These weren't being checked for
by the code.

Also, fix places in c-get-fontification-context where point is undefined.

* lisp/progmodes/cc-fonts.el (c-get-fontification-context): when argument
not-front-decl is set, test for class initializers.  Also, anchor point in
places where it is moved and is otherwise undefined.

Fix variables in C++ "for" statement not always being fontified.

The error happened when there was a comma inside template delimiters.

* lisp/progmodes/cc-fonts.el (c-get-fontification-context): In "for"
statements, recognise template delimiters containing "," and "&".

Add watchdog process to tramp-test36-asynchronous-requests

* test/lisp/net/tramp-tests.el (tramp--test-timeout-handler):
New defun.
(tramp-test36-asynchronous-requests): Use a watchdog process,
listening for SIGUSR1.

CC Mode: Fix declarator being cut off from terminator by end of jit-lock chunk

If a declarator is so cut off, extend the fontification chunk to include it.

* lisp/progmodes/cc-mode.el (c-fl-decl-end): New function.
(c-change-expand-fl-region, c-context-expand-fl-region): Use the new function.

* lisp/vc/smerge-mode.el: Avoid N² blow up in degenerate cases

(smerge--refine-long-words): New var.
(smerge--refine-chopup-region): Use it.

* lisp/url/url-cookie.el: Use lexical-binding

(url-cookie-host-can-set-p): Remove unused var `last'.
Use string-suffix-p.
(url-cookie-list): De morgan.
(url-cookie-quit): Remove.
(url-cookie-mode): Inherit from special-mode.
(url-cookie-mode-map): Simplify accordingly.

* lisp/calendar/todo-mode.el (todo-print-buffer-function): Rework docstring.

* lisp/ruler-mode.el (ruler-mode-ruler): Document problem.

* lisp/emacs-lisp/cl-generic.el (cl-generic-define-method):

Record this as the function's definition site if it's the first def.

* doc/lispref/loading.texi (When to Autoload): New section.

Stop using unibyte buffers for ert backtraces

* lisp/emacs-lisp/ert.el
(ert-results-pop-to-backtrace-for-test-at-point):
Set multibyte true, not false.  This copies a
debugger-setup-buffer change from 2009-08-30, and stops the
"Backtrace for" header line containing ^X and ^Y.

Fix semantic-symref-parse-tool-output-one-line after 644cdd1aa0

* lisp/cedet/semantic/symref/grep.el
(semantic-symref-grep--line-re): Delete.
(semantic-symref-parse-tool-output-one-line):
Use regexp and group numbers from (grep-regexp-alist).

Fix cl-defmethod indentation

* lisp/emacs-lisp/cl-generic.el (cl-defmethod):
Declare (indent defun).  Fixes bug#23994.

Fix two customization types in frame.el

* lisp/frame.el (window-divider-default-bottom-width)
(window-divider-default-right-width): Fix customization types.

Dired: Support eshell-ls from the beginning if the user wants to

* lisp/dired.el (dired-insert-directory): Check for eshell-ls
as well (Bug#27817).
* test/lisp/dired-tests.el (dired-test-bug27817): Add test.

* lisp/progmodes/sh-script.el (sh-mode): Recognize mkshrc.

* lisp/emacs-lisp/eieio-compat.el (eieio--defgeneric-init-form):

Adjust to change in cl-generic-ensure-function.

; Instrument entry of tramp--test-instrument-test-case

ls-lisp: Add an unload function and enable lexical binding

Enable lexical binding.
* lisp/ls-lisp.el (ls-lisp-unload-function): New defun.
* test/lisp/ls-lisp.el (ls-lisp-unload): Add test.

register-read-with-preview: Quit if user input C-g or ESC

* lisp/register.el (register-read-with-preview):
Quit if user input C-g or ESC (bug#27634).
* doc/emacs/regs.texi (Registers): Update manual.
* test/lisp/register-tests.el (register-test-bug27634): Add test.

; Fix previous commit

Functions prefixed with `turn-on-foo' are quite old, and in general
subsumed by the corresponding `foo-mode` command.
* lisp/display-line-numbers.el (turn-on-display-line-numbers-mode):
Rename with library prefix, mark as internal.  Nix autoload.

Recognize MirBSD Korn shell rc file

* lisp/files.el (auto-mode-alist): Add .mkshrc to the list.

* configure.ac: Be explicit about ImageMagick version in summary.

Properly align global lispsym

* lib-src/make-docfile.c (close_emacs_globals): Wrap struct
Lisp_Symbols inside struct.
* src/alloc.c (sweep_symbols): Update use of lispsym.
* src/lisp.h (builtin_lisp_symbol): Likewise.

Do not use ImageMagick 7 and later

Suggested by Glenn Morris (Bug#25967#15).
* configure.ac (IMAGEMAGICK_MODULE): Reject 7 and later.

* lisp/progmodes/perl-mode.el: Add support for indented here docs

* lisp/progmodes/perl-mode.el (perl-syntax-propertize-function):
Recognize the new <<~ syntax for indented here docs.
(perl-syntax-propertize-special-constructs): Adjust search of the
end of here docs accordingly.

* test/manual/indent/perl.perl: Add test for indented here docs.

(loadhist-unload-element): Move ERT and cl-generic methods

* lisp/loadhist.el (loadhist-unload-element): Don't define cl-generic
and ert methods here.
(loadhist-unload-element) <(head define-type)>: Remove unused var `slots'.

* lisp/emacs-lisp/cl-generic.el (loadhist-unload-element): Define
unload method for cl-defmethod.
(cl-generic-ensure-function): Remove redundant `defalias'.

* lisp/emacs-lisp/ert.el (ert-set-test): Move the current-load-list
setting here...
(ert-deftest): ...from here.
(loadhist-unload-element): Define unload method for ert-deftest.

Fix Bug#27371

* lisp/loadhist.el (loadhist-unload-element): Declare for
different entry types of `load-history'.
(loadhist--restore-autoload): New variable.
(loadhist--unload-function): New defun.
(unload-feature): Use `loadhist-unload-element'.  Recommended by
Stefan Monnier.  (Bug#27371)

* test/lisp/net/tramp-tests.el (tramp-test39-unload):
Check, that the `tramp-file-name' structure has been unloaded.

Ensure that we parse images right in shr.el

* lisp/net/shr.el (shr-image-fetched): Go back to the
beginning of the buffer before trying to parse the image
fetched.

Update .gitignore for Valgrind and no Automake

* .gitignore: Remove .deps/ since we no longer use Automake.
Add vgcore.*[0-9], for debugging Emacs with Valgrind+GDB.

Merge from gnulib

This incorporates:
2017-07-23 Rename module 'strftime' to 'nstrftime'
* admin/merge-gnulib (GNULIB_MODULES): Add nstrftime, remove strftime.
* build-aux/config.guess: Copy from gnulib.
* lib/nstrftime.c: Rename from lib/strftime.c.
* m4/nstrftime.m4: Rename from m4/strftime.m4.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

; Don't keep temporary buffers alive after a dired test

* test/lisp/dired-tests.el (dired-test-bug22694)
(dired-test-bug25609, dired-test-bug27243)
Delete all temporary dired buffers at the end.

Add 'rx' pattern for pcase.

* lisp/emacs-lisp/rx.el (rx): New pcase macro.
* test/lisp/emacs-lisp/rx-tests.el (rx-pcase): Add unit test.

Use a named function for global minor mode turn-on argument

* lisp/display-line-numbers.el (turn-on-display-line-numbers-mode):
New function.
(global-display-line-numbers-mode): Use it.

Enable GUI Emacs without 'make install' on macOS (Bug #27645)

* nextstep/INSTALL: Correct it, and mention that Emacs can be run
from 'src/emacs'.

* src/nsterm.m (applicationDidFinishLaunching:): When Emacs is
launched outside of a macOS application bundle, change its
activation policy from the default 'prohibited' to 'regular'.

; * etc/NEWS: Mention the change on macOS.

Convert CC Mode's c-found-types from an obarray to a hash table.

* lisp/progmodes/cc-engine.el (c-clear-found-types): create a hash table
rather than an obarray.
(c-copy-found-types): Remove.
(c-add-type, c-unfind-type, c-check-type, c-list-found-types): Amend to use
the new hash table.
(c-forward-<>-arglist): Use copy-hash-table rather than c-copy-found-types.

Fix image/svg+xml display in shr

* lisp/net/shr.el (shr-put-image): Display svg images as svg
(bug#27799).  I suspect the previous change was checked in by
accident in conjuction with some other svg changes.

* lisp/display-line-numbers.el (display-line-numbers-type): Autoload it.

Don't automatically enable Gconf if Gsettings was found

* configure.ac (HAVE_GCONF) [HAVE_GSETTINGS]:
Don't test for Gconf unless specifically requested.
Gconf was deprecated in favor of Gsettings several years ago.

* configure.ac (MODULES_SUFFIX): Always give it a value.

This prevents a Makefile thinko like "rm *${MODULE_SUFFIX}".

* doc/emacs/frames.texi (Fonts): Mention Gsettings.

Add line numbers display to the Options menu

* lisp/menu-bar.el (toggle-display-line-numbers): Remove.
(menu-bar-display-line-numbers-mode): New defun.
(menu-bar-showhide-line-numbers-menu): New defvar.
(menu-bar-showhide-menu): Use `menu-bar-showhide-line-numbers-menu'

; * CONTRIBUTE: Rearrange sections into a more logical order.

Signal error for symbol names with strange quotes (Bug#2967)

* src/lread.c (read1): Signal an error when a symbol starts with a
non-escaped quote-like character.
* test/src/lread-tests.el (lread-tests--funny-quote-symbols): New
test.
* etc/NEWS: Announce change.

Revert "Let delete-selection-mode work with popup-menu commands (Bug#27569)"

It turns out that this change is not needed, and it leaves several
command loops settings not done.

https://lists.gnu.org/archive/html/emacs-devel/2017-07/msg00757.html
https://lists.gnu.org/archive/html/emacs-devel/2017-07/msg00840.html

Add a minor mode interface for display-line-numbers

* lisp/cus-start.el: Use the new display-line-numbers group.
* lisp/display-line-numbers.el: New file.

* doc/emacs/custom.texi (Init Rebinding): Re-add entry that used to
belong to linum-mode.
* doc/emacs/modes.texi (Minor Modes): Summarize the mode.
* etc/NEWS: Document display-line-numbers-mode and its customization
variables, and mention that display-line-numbers-width is
buffer-local.

* src/xdisp.c (syms_of_xdisp) <display-line-numbers-width>: Fix a
typo.

Support indented HERE-DOCs in cperl-mode

* lisp/progmodes/cperl-mode.el (cperl-find-pods-heres): Support
indented here-docs.  (Bug#27254) (Bug#27697)

Copyright-paperwork-exempt: yes

Document the support for "scrollBar" X resource

* doc/emacs/xresources.texi (Table of Resources): Document the new
'scrollBar' setting.
* etc/NEWS: Document the new 'scrollBar' setting.

Add 'scroll-bar-mode' to settings in 'x-apply-session-resources'

* lisp/startup.el (x-apply-session-resources): Add scroll-bar-mode
settings.

Copyright-paperwork-exempt: yes

Update ld-script mode (bug#27629)

* lisp/progmodes/ld-script.el: (ld-script-keywords): New commands
NOCROSSREFS_TO and HIDDEN added.  Fix documentation sections
numbers for PROVIDE/PROVIDE_HIDDEN commands.
(ld-script-builtins): New builtin function LOG2CEIL added.

Index 'rectangle' in the ELisp manual

* doc/lispref/text.texi (Registers): Index the "rectangle" value.
(Bug#27541)

* lisp/subr.el (add-to-history): Doc fix.  (Bug#27494)

Doc fixes for kmacro.el functions

* lisp/kmacro.el (kmacro-start-macro, kmacro-call-macro)
(kmacro-end-and-call-macro): Don't use "permanent name", as that
could be misinterpreted.  (Bug#27492)

ElDoc: add docstrings and minor refactoring

* lisp/emacs-lisp/eldoc.el (eldoc-edit-message-commands): Add
docstring.
(turn-on-eldoc-mode): Fix capitalization.
(eldoc--supported-p): Add docstring.
(eldoc-schedule-timer): Add docstring and use
'eldoc--supported-p'.
(eldoc-message): Add docstring and make calling convention
clearer.
(eldoc--message-command-p):
(eldoc-pre-command-refresh-echo-area):
(eldoc-display-message-p):
(eldoc-display-message-no-interference-p):
(eldoc-print-current-symbol-info):
(eldoc-docstring-format-sym-doc):
(eldoc-add-command, eldoc-add-command-completions):
(eldoc-remove-command, eldoc-remove-command-completions):
Add docstring.  (Bug#27230)

Mention 'C-M-i' as key binding for 'ispell-complete-word'

* doc/emacs/fixit.texi (Spelling): ispell-complete-word
can also be invoked by C-M-i.  (Bug#27349)

Copyright-paperwork-exempt: yes

; * doc/emacs/search.texi (Word Search): Update for changes in bug#27341.

Fix the eww-search-words description in the Emacs manual

* doc/emacs/search.texi (Word Search):
Include the key binding for eww-search-words in the manual.
Fix the spelling of the 'eww-search-words' command.

Copyright-paperwork-exempt: yes

Introduce defcustom 'executable-prefix-env'

* lisp/progmodes/executable.el (executable-prefix): Update the doc
string.
(executable-prefix-env): New defcustom.
(executable-set-magic): Use executable-prefix-env.

* etc/NEWS: Document the new variable.

* test/lisp/ibuffer-tests.el: Delete temporary files.

Further attempt to avoid hang in network-stream-tests

* test/lisp/net/network-stream-tests.el (connect-to-tls-ipv6-nowait):
Limit the time we wait for the external process.

Stop skipping many ibuffer tests by default

* test/lisp/ibuffer-tests.el (ibuffer-0autoload):
Rename so it sorts first.
(ibuffer-save-filters, ibuffer-filter-inclusion-1)
(ibuffer-filter-inclusion-2, ibuffer-filter-inclusion-3)
(ibuffer-filter-inclusion-4, ibuffer-filter-inclusion-5)
(ibuffer-filter-inclusion-6, ibuffer-filter-inclusion-7)
(ibuffer-filter-inclusion-8, ibuffer-decompose-filter)
(ibuffer-and-filter, ibuffer-or-filter, ibuffer-format-qualifier)
(ibuffer-unary-operand): Require ibuf-ext so tests not skipped.

Use lexical-binding in todo-mode.el

Adjust code accordingly and make various minor improvements.

* lisp/calendar/todo-mode.el: Enable lexical-binding.
(dayname, monthname, day, month, year): Make forward defvars
of these keywords from macros defined in calendar.el; wrap
them in with-no-warnings.
(todo-files, todo-files-function, todo-date-pattern)
(todo-mode-line-function, todo-show, todo-forward-category)
(todo-edit-item--header, todo-set-category-number)
(todo-adjusted-category-label-length)
(todo-total-item-counts, todo-filter-items)
(todo-print-buffer-function, todo-convert-legacy-date-time)
(todo-category-number, todo-category-completions)
(todo-read-file-name, todo-read-category)
(todo-validate-name, todo-read-date)
(todo-set-show-current-file, todo-modes-set-1)
(todo-modes-set-2, todo-modes-set-3, todo-mode):
Use #' instead of ' to quote functions.
(todo-files): Use \' instead of $ in regexp.
(todo--files-type-list): New function.
(todo-default-todo-file, todo-category-completions-files)
(todo-filter-files, todo-multiple-filter-files)
(todo-reevaluate-default-file-defcustom)
(todo-reevaluate-category-completions-files-defcustom)
(todo-reevaluate-filter-files-defcustom): Use it.
(todo-show, todo-rename-file, todo-move-category)
(todo-edit-item--text, todo-edit-quit, todo-edit-item--header)
(todo-item-undone, todo-unarchive-items, todo-search)
(todo-filter-items, todo-filter-items-1, todo-find-item)
(todo-category-select, todo-read-date)
(todo-nondiary-marker-matcher, todo-date-string-matcher)
(todo-diary-expired-matcher, todo-convert-legacy-files)
(todo-read-category): Reformat to avoid code hiding behind a
more deeply embedded element.
(todo-forward-category, todo-set-category-number):
Use 'funcall' instead of 'apply'.
(todo-toggle-mark-item, todo-edit-item--diary-inclusion)
(todo-edit-category-diary-inclusion)
(todo-insert-sort-button, todo-insert-category-line)
(todo-multiple-filter-files): Mark unused local variables.
(todo-edit-item--header, todo-move-item, todo-print-buffer)
(todo-edit-item--header, todo-move-item, todo-check-file)
(todo-edit-item--next-key): Remove unused local variables.
(todo-insert-sort-button, todo-insert-category-line):
Use a closure instead of a backquoted lambda.
(todo-update-categories-display, todo-print-buffer): Simplify code.
(todo-print-buffer-function): Document calling convention.
(todo-category-completions): Use cl-pushnew instead of add-to-list.
(todo-mode-map, todo-archive-mode-map)
(todo-categories-mode-map, todo-filtered-items-mode-map):
Remove superfluous call of suppress-keymap, since it's already
in the parent special-mode-map.

dired: Revert buffer when DIRNAME is a cons

* lisp/dired.el (dired-internal-noselect): Revert buffer if DIR-OR-LIST
is a cons, or dired-directory is a cons and DIR-OR-LIST a string (Bug#7131).
Update the comments.
* test/lisp/dired-tests.el (dired-test-bug7131): Test should pass.

; * etc/NEWS: Fix format of an entry.

Handle when dired-directory is a cons in some Dired functions

* lisp/dired-aux.el (dired-rename-subdir-1)
* lisp/dired-x.el (dired-mark-omitted):
Handle when dired-directory is a cons.

Make eshell-next-prompt more reliable (Bug#27405)

* lisp/eshell/em-prompt.el (eshell-next-prompt): Search for
`eshell-prompt-regexp' (and `read-only' text-property if
`eshell-highlight-prompt' is set) rather than trying to use
`forward-paragraph'.
(eshell-previous-prompt): Don't count prompt on current line.

Simplify recent gnutls.c changes

* src/gnutls.c (clear_storage) [HAVE_GNUTLS3_AEAD]: Remove.
All uses replaced by calls to explicit_bzero; that’s clear enough.
(gnutls_symmetric_aead) [HAVE_GNUTLS3_AEAD]: Simplify by
coalescing duplicate actions.  There is no need to invoke
SAFE_FREE before calling ‘error’.

; Spelling fixes

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

Stylistic changes in tramp-cache.el

* test/lisp/net/tramp-cache.el (tramp-get-file-property)
(tramp-set-file-property): Use `bound-and-true-p'.  Add
counter variables to `tramp-cache-unload-hook'.

* admin/notes/hydra: Small updates.

Make tramp unloading handle debug counter variables

* lisp/net/tramp-cache.el (tramp-get-file-property)
(tramp-set-file-property): Add counter variables to tramp-unload-hook.

Fix hscrolling calculations when display-line-numbers is set

* src/xdisp.c (move_it_in_display_line_to): Account for line
numbers in hscrolled lines.  (Bug#27756)

Fix the bogus change made 13 years ago (bug#27084)

* lisp/gnus/gnus-sum.el (gnus-summary-toggle-header):
Fix the way to test if there is no visible header (bug#27084).

Use grep's --null option (Bug#6843)

* lisp/progmodes/grep.el (grep-use-null-filename-separator): New option.
(grep--regexp-alist-column, grep--regexp-alist-bin-matcher)
(grep-with-null-regexp-alist, grep-fallback-regexp-alist): New
constants, replacing `grep-regexp-alist'.
(grep-regex-alist): Mark the variable obsolete, add a new function of
the same name to replace it.
(grep-compute-defaults): Compute default for
`grep-use-null-filename-separator'.
(grep-mode): Set compilation-error-regexp-alist (buffer locally) to the
value of `grep-with-null-regexp-alist' or `grep-fallback-regexp-alist'
according to `grep-use-null-filename-separator'.
* lisp/progmodes/xref.el (xref-collect-matches): Call
`grep-regex-alist' instead of the obsolete variable.  Don't hardcode
grep-regexp-alist match groups.
* etc/NEWS: Announce new use of --null.  Move 'grep-save-buffers'
item under "Grep" heading as well.

* src/gnutls.c (clear_storage): Define only if needed.

Adjust todo-quit to recent change in dired

* lisp/calendar/todo-mode.el (todo-quit): Use quit-window instead of
bury-buffer to exit todo-mode.  This restores the desired behavior
of not immediately returning to the exited todo-mode buffer on
quitting another buffer, which a dired bug fix had changed (see
http://lists.gnu.org/archive/html/emacs-devel/2017-07/msg00739.html).