GNU Emacs NEWS -- history of user-visible changes.

Copyright (C) 2022-2025 Free Software Foundation, Inc.
See the end of the file for license conditions.

Please send Emacs bug reports to 'bug-gnu-emacs@gnu.org'.
If possible, use 'M-x report-emacs-bug'.

This file is about changes in Emacs version 31.

See file HISTORY for a list of GNU Emacs versions and release dates.
See files NEWS.30, NEWS.29, ..., NEWS.18, and NEWS.1-17 for changes
in older Emacs versions.

You can narrow news to a specific version by calling 'view-emacs-news'
with a prefix argument or by typing 'C-u C-h C-n'.

Temporary note:
+++ indicates that all relevant manuals in doc/ have been updated.
--- means no change in the manuals is needed.
When you add a new item, use the appropriate mark if you are sure it
applies, and please also update docstrings as needed.


* Installation Changes in Emacs 31.1

+++
** Unexec dumper removed.
The traditional unexec dumper, deprecated since Emacs 27, has been
removed.

** Changed GCC default options on 32-bit x86 systems.
When using GCC 4 or later to build Emacs on 32-bit x86 systems,
'configure' now defaults to using the GCC options '-mfpmath=sse' (if the
host system supports SSE2) or '-fno-tree-sra' (if not).  These GCC
options work around GCC bug 58416, which can cause Emacs to behave
incorrectly in rare cases.


* Startup Changes in Emacs 31.1

** In compatible terminals, 'xterm-mouse-mode' is turned on by default.
For these terminals the mouse will work by default.  A compatible
terminal is one that supports Emacs setting and getting the OS selection
data (a.k.a. the clipboard) and mouse button and motion events.  With
'xterm-mouse-mode' enabled, you must use Emacs keybindings to copy to the
OS selection instead of terminal-specific keybindings.

You can keep the old behavior by putting '(xterm-mouse-mode -1)' in your
init file.


* Changes in Emacs 31.1

+++
** 'standard-display-table' now has more extra slots.
'standard-display-table' has been extended to allow specifying glyphs
that are used for borders around child frames and menu separators on TTY
frames.

Call the function 'standard-display-unicode-special-glyphs' to set up
the 'standard-display-table's extra slots with Unicode characters.
Please see the documentation of that function to see which slots of the
display table it changes.

** Child frames are now supported on TTY frames.
This supports use-cases like Posframe, Corfu, and child frames acting
like tooltips.  Other use-cases of child frames are not supported yet.
In particular:

- trying to create minibuffer-only child frames on a TTY frame will
  signal an error; and
- a TTY child frame cannot be converted to a root frame or vice-versa.

To enable tooltips on TTY frames, call 'tty-tip-mode'.

The presence of child frame support on TTY frames can be checked with
'(featurep 'tty-child-frames)'.

Recent versions of Posframe and Corfu are known to use child frames on
TTYs if they are supported.

+++
** Several font-lock face variables are now obsolete.
The following variables are now obsolete: 'font-lock-builtin-face',
'font-lock-comment-delimiter-face', 'font-lock-comment-face',
'font-lock-constant-face', 'font-lock-doc-face',
'font-lock-doc-markup-face', 'font-lock-function-name-face',
'font-lock-keyword-face', 'font-lock-negation-char-face',
'font-lock-preprocessor-face', 'font-lock-string-face',
'font-lock-type-face', 'font-lock-variable-name-face', and
'font-lock-warning-face'.

These variables contributed both to confusion about the relation between
faces and variables, and to inconsistency when major mode authors used
one or the other (sometimes interchangeably).  We always recommended
using faces directly, and not creating variables going by the same name.

If you have customized these variables, you should now customize the
corresponding faces instead, using something like:

    M-x customize-face RET font-lock-string-face RET

If you have been using these variables in Lisp code (for example, in
font-lock rules), simply quote the symbol, to use the face directly
instead of its now-obsolete variable.

** Network Security Manager (NSM) is now more strict.

*** NSM warns about TLS 1.1 by default.
It has been deprecated by RFC 8996, published in 2021.

*** NSM warns about DHE and RSA key exchange by default.
Emacs now warns about ephemeral Diffie-Hellman key exchange, and static
RSA key exchange, also when 'network-security-level' is customized to
its default 'medium' value.

** Etags

+++
*** New command-line options for handling unrecognized programming languages.
The new command-line option '--no-fallback-lang' disables attempts to
parse as Fortran or C/C++ files whose programming language 'etags' could
not determine.  This allows to avoid false positives and reduces the time
required to scan directories with many such files.  Another new option
'--no-empty-file-entries' disables generation of file entries in tags
tables for files in which no tags were found.

---
** find-func.el commands now have history enabled.
The 'find-function', 'find-library', 'find-face-definition', and
'find-variable' commands now allow retrieving previous input using the
usual minibuffer history commands.  Each command has a separate history.

---
** New minor mode 'find-function-mode' replaces 'find-function-setup-keys'.

** Minibuffer and Completions

+++
*** New user option 'completion-eager-display'.
This option configures whether completion commands should display the
"*Completions*" buffer immediately.  When the option is set to t, all
completion commands show "*Completions*" immediately, respectively nil
disables the eager display for all commands.  The default setting auto
enables eager completion only if requested by the command.
For more fine-grained control you can also toggle this feature by
category using the symbol 'eager-display' in the user option
'completion-category-overrides'.

+++
*** New user option 'completion-pcm-leading-wildcard'.
This option configures how the partial-completion style does completion.
It defaults to nil, which preserves the existing behavior.  When it is set
to t, the partial-completion style behaves more like the substring
style, in that a string being completed can match against a candidate
anywhere in the candidate string.

+++
*** 'completion-styles' now can contain lists of bindings.
In addition to being a symbol naming a completion style, an element of
'completion-styles' can now be a list of the form '(STYLE ((VARIABLE
VALUE) ...))' where STYLE is a symbol naming a completion style.
VARIABLE will be bound to VALUE (without evaluating it) while the style
is executing.  This allows multiple references to the same style with
different values for completion-affecting variables like
'completion-pcm-leading-wildcard' or 'completion-ignore-case'.  This also
applies for the styles configuration in 'completion-category-overrides'
and 'completion-category-defaults'.

---
*** Selected completion candidate is preserved across "*Completions*" updates.
When point is on a completion candidate in the "*Completions*" buffer
(because of 'minibuffer-next-completion' or for any other reason), point
will still be on that candidate after "*Completions*" is updated with a
new list of completions.  The candidate is automatically deselected when
the "*Completions*" buffer is hidden.

---
*** New user option 'crm-prompt' for 'completing-read-multiple'.
This option configures the prompt format of 'completing-read-multiple'.
By default, the prompt indicates to the user that the completion command
accepts a comma-separated list.  The prompt format can include the
separator description and the separator string, which are both stored as
text properties of the 'crm-separator' regular expression.

** Windows

+++
*** New functions to modify window layout.
Several functions to modify the window layout have been added:
'rotate-window-layout-clockwise', 'rotate-window-layout-anticlockwise',
'flip-window-layout-vertically', 'flip-window-layout-horizontally',
'transpose-window-layout', 'rotate-windows', and 'rotate-windows-back'.

+++
*** New hook 'window-deletable-functions'.
This abnormal hook gives its client a way to save a window from getting
deleted implicitly by functions like 'kill-buffer', 'bury-buffer' and
'quit-restore-window'.

+++
*** New user option 'quit-window-kill-buffer'.
This option specifies whether 'quit-window' should preferably kill or
bury the buffer shown by the window to quit.

+++
*** New user option 'kill-buffer-quit-windows'.
This option has 'kill-buffer' call 'quit-restore-window' to handle the
further destiny of any window showing the buffer to be killed.

+++
*** 'split-window' can optionally resurrect deleted windows.
A new argument REFER of 'split-window' makes it possible to, instead of
making a new window object, reuse an existing, deleted one.  This can be
used to preserve the identity of windows when swapping or transposing
them.

+++
*** New window parameter 'quit-restore-prev'.
This parameter is set up by 'display-buffer' when it detects that the
window used already has a 'quit-restore' parameter.  Its presence gives
'quit-restore-window' a way to undo a sequence of buffer display
operations more intuitively.

+++
*** 'quit-restore-window' handles new values for BURY-OR-KILL argument.
The values 'killing' and 'burying' are like 'kill' and 'bury' but assume
that the actual killing or burying of the buffer is done by the caller.

+++
*** New user option 'quit-restore-window-no-switch'.
With this option set, 'quit-restore-window' will delete its window more
aggressively rather than switching to some other buffer in it.

---
*** The user option 'display-comint-buffer-action' has been removed.
It has been obsolete since Emacs 30.1.  Use '(category . comint)' instead.
Another user option 'display-tex-shell-buffer-action' has been removed too
for which you can use '(category . tex-shell)'.

+++
*** New user option 'split-window-preferred-direction'.
Users can now choose in which direction Emacs tries to split first:
vertical or horizontal.  With this new setting, when the frame is in
landscape shape for instance, Emacs could split horizontally before
splitting vertically.  The default setting preserves Emacs historical
behavior to try to split vertically first.

** Frames

+++
*** New function 'frame-deletable-p'.
Calling this function before 'delete-frame' is useful to avoid that the
latter throws an error when the argument FRAME cannot be deleted.

+++
*** New value 'force' for option `frame-inhibit-implied-resize'.
This will inhibit implied resizing while a new frame is made and can be
useful on tiling window managers where the initial frame size should be
specified by external means.

** Tab Bars and Tab Lines

---
*** New abnormal hook 'tab-bar-auto-width-functions'.
This hook allows you to control which tab-bar tabs are auto-resized.

---
*** New abnormal hook 'tab-bar-post-undo-close-tab-functions'.
This hook allows you to operate on a reopened tab.

This is useful when you define custom tab parameters that may need
adjustment when a tab is restored, and avoids advice.

---
*** New user option 'tab-bar-define-keys'.
This controls which key bindings tab-bar creates.  Values are t, the
default, which defines all keys and is backwards compatible, 'numeric'
(tab number selection only), 'tab' ('TAB' and 'S-TAB' keys only), nil
(which defines none).

This is useful to avoid key binding conflicts, such as when folding in
outline mode using 'TAB' keys, or when a user wants to define her own
tab-bar keys without first having to remove the defaults.

---
*** New variable 'tab-bar-format-tab-help-text-function'.
This variable may be overridden with a user-provided function to
customize help text for tabs displayed on the tab-bar.  Help text is
normally shown in the echo area or via tooltips.  See the variable's
docstring for arguments passed to a help-text function.

** Project

---
*** New command 'project-root-find-file'.
It is equivalent to running ‘project-any-command’ with ‘find-file’.

---
*** Improved prompt for 'project-switch-project'.
The prompt now displays the chosen project on which to invoke a command.

---
*** The MAYBE-PROMPT argument of 'project-current' can be a string.
When such value is used, the 'project-prompter' is called with it as the
first argument.  This is a way for the callers to indicate, for example,
the reason or the context why the project is asked for.

---
*** New command 'project-find-matching-file'.
It can be used when switching between projects with similar file trees
(such as Git worktrees of the same repository).  It supports being
invoked standalone or from the 'project-switch-commands' dispatch menu.

** Registers

*** New functions 'buffer-to-register' and 'file-to-register'.
These allow users to interactively store file and buffers in registers.
Killed buffers stored in a register using 'buffer-to-register' are
automatically converted to a file-query value if the buffer was visiting
a file.

** IDLWAVE has been moved to GNU ELPA.
The version bundled with Emacs is out-of-date, and is now marked as
obsolete.  Use 'M-x list-packages' to install the 'idlwave' package from
GNU ELPA instead.

+++
** New faces 'header-line-active' and 'header-line-inactive'.
These inherit from the 'header-line' face, but the faces actually used
on the header lines are now these two: the selected window uses
'header-line-active', non-selected windows use 'header-line-inactive'.

** In 'customize-face', the "Font family" attribute now supports completion.

** 'process-adaptive-read-buffering' is now nil by default.
Setting this variable to a non-nil value reduces performance and leads
to wrong results in some cases.  We believe that it is no longer useful;
please contact us if you still need it for some reason.


* Editing Changes in Emacs 31.1

** Commands for keyboard translation.
'key-translate' is now interactive.  It prompts for a key to translate
from, and another to translate to, and sets 'keyboard-translate-table'.
The new command 'key-translate-remove' prompts for a key/translation
pair with 'completing-read', and removes it from the translation table.

** Internationalization

---
*** Emacs now supports Unicode version 16.0.

---
*** New input method 'greek-polytonic'.
This input method has support for polytonic and archaic Greek
characters.

---
*** New language environment and input method for Tifinagh.
The Tifinagh script is used to write the Berber languages.

---
*** New input methods for Northern Iroquoian languages.
Input methods are now implemented for Haudenosaunee languages in the
Northern Iroquoian language family: 'mohawk-postfix' (Mohawk
[Kanien’kéha / Kanyen’kéha / Onkwehonwehnéha]), 'oneida-postfix' (Oneida
[Onʌyote’a·ká· / Onyota’a:ká: / Ukwehuwehnéha]), 'cayuga-postfix'
(Cayuga [Gayogo̱ho:nǫhnéha:ˀ]), 'onondaga-postfix' (Onondaga
[Onųdaʔgegáʔ]), and 'seneca-postfix' (Seneca [Onödowá’ga:’]).
Additionally, there is a general-purpose 'haudenosaunee-postfix' input
method to facilitate writing in the orthographies of the five languages
simultaneously.

---
** 'visual-wrap-prefix-mode' now supports variable-pitch fonts.
When using 'visual-wrap-prefix-mode' in buffers with variable-pitch
fonts, the wrapped text will now be lined up correctly so that it's
exactly below the text after the prefix on the first line.

---
** New commands 'unix-word-rubout' and 'unix-filename-rubout'.
Unix-words are words separated by whitespace regardless of the buffer's
syntax table.  In a Unix terminal or shell, 'C-w' kills by Unix-word.
The new commands 'unix-word-rubout' and 'unix-filename-rubout' allow
you to bind keys to operate more similarly to the terminal.

---
** New user option 'kill-region-dwim'.
This option, if non-nil, modifies the fall-back behavior of
'kill-region' ('C-w') if no region is active, and will kill the last word
instead of raising an error.  Note that if you have disabled Transient
Mark mode you might prefer to use 'unix-word-rubout', as this feature
relies on there being an active region.

---
** New user option 'delete-pair-push-mark'.
This option, if non-nil, makes 'delete-pair' push a mark at the end of
the region enclosed by the deleted delimiters.  This makes it easy to
act on that region.  For example, we can highlight it using 'C-x C-x'.

+++
** Electric Pair mode can now pair multiple delimiters at once.
You can now insert or wrap text with multiple sets of parentheses and
other matching delimiters at once with Electric Pair mode, by providing
a prefix argument when inserting one of the delimiters.

+++
** You can now use 'M-~' during 'C-x s' ('save-some-buffers').
Typing 'M-~' while saving some buffers means not to save the buffer and
also to mark it as unmodified.  This is an alternative way to mark a
buffer as unmodified which doesn't require switching to that buffer.

** New minor mode 'delete-selection-local-mode'.
This mode sets 'delete-selection-mode' buffer-locally.  This can be
useful for enabling or disabling the features of 'delete-selection-mode'
based on the state of the buffer, such as for the different states of
modal editing packages.


* Changes in Specialized Modes and Packages in Emacs 31.1

---
** ASM mode

*** 'asm-mode-set-comment-hook' is obsolete.
You can now set `asm-comment-char' from 'asm-mode-hook' instead.

---
** Ibuffer

*** New column 'recency' in Ibuffer display.
The user option 'ibuffer-formats' configures the Ibuffer formats.  Add
'recency' to the format to display the column.

*** New value 'title' for the user option 'ibuffer-use-header-line'.
Display column titles in the header line if 'ibuffer-use-header-line' is
set to 'title'.

*** New user option 'ibuffer-human-readable-size'.
When non-nil, buffer sizes are shown in human readable format.

---
*** 'define-ibuffer-op' prompts can now be functions.
The prompts 'opstring' and 'active-opstring' can now either be strings
or functions.  This is useful when your prompts can benefit from dynamic
content.

---
** Buffer Menu

*** New user option 'Buffer-menu-human-readable-sizes'.
When non-nil, buffer sizes are shown in human readable format.  The
default is nil, which retains the old format.

** Smerge

*** New command 'smerge-extend' extends a conflict over surrounding lines.

*** New command 'smerge-refine-exchange-point' to jump to the other side.
When used inside a refined chunk, it jumps to the matching position in
the "other" side of the refinement: if you're in the new text, it jumps
to the corresponding position in the old text and vice versa.

** Image Dired

*** 'image-dired-show-all-from-dir' takes the same first argument as 'dired'.
This allows passing a string with wildcards, or a cons cell where the
first element is a list and the rest is a list of files.

*** Bound unused letters in 'image-dired-thumbnail-mode-map'.
For a more comfortable navigation experience (as in, no modifier keys),
the keys 'f', 'b', 'n', 'p', 'a' and 'e' are now bound to the
same functions as their 'C-' counterparts.

** Browse URL

*** New user option 'browse-url-transform-alist'.
This user option is an alist that allows transforming URLs before asking
a web browser to load them.  For example, it could be used like this:

    (add-to-list 'browse-url-transform-alist
                 '("www.google.com" . "www.duckduckgo.com"))

*** New function 'browse-url-qutebrowser' for Qutebrowser.
For better integration with Qutebrowser, set
'browse-url(-secondary)-browser-function' to 'browse-url-qutebrowser'.

*** New GTK-native launch mode.
For better Wayland support, the pgtk toolkit exposes a new
'x-gtk-launch-uri' browse-url handler and uses it by default when URLs
are browsed from a PGTK frame.  For other frames, we fall back to the
default URL launch function.  This change allows us to properly raise
browser windows under Wayland using the xdg_activation_v1 protocol.

*** Removed support for some obsolete web browsers.
Conkeror (obsolete since Emacs 28.1), gnome-moz-remote (obsolete since
Emacs 25.1), and gnudoit (obsolete since Emacs 25.1).

** CL-Lib

+++
*** Some cl-lib functions and macros are now built-in.
These functions or macros have been added to Emacs Lisp, and the old
names are now aliases for the built-in equivalents:
 - 'cl-incf'   renamed to 'incf'
 - 'cl-decf'   renamed to 'decf'
 - 'cl-oddp'   renamed to 'oddp'
 - 'cl-evenp'  renamed to 'evenp'
 - 'cl-plusp'  renamed to 'plusp'
 - 'cl-minusp' renamed to 'minusp'

The old names are considered deprecated, and will be marked as obsolete
in some future release.

+++
*** 'cl-labels' now also accepts '(FUNC EXP)' bindings, like 'cl-flet'.
Such bindings make it possible to compute which function to bind to FUNC.

---
*** 'cl-block' names are now lexically scoped, as documented.

+++
*** 'cl-locally' is now obsolete.
It is an alias for the 'progn' special-form.

** Whitespace

---
*** 'whitespace-cleanup' now adds missing newline at end of file.
If 'whitespace-style' includes 'missing-newline-at-eof' (which is the
default), the 'whitespace-cleanup' function will now add the newline.

** Bookmark

---
*** Bookmark history now saves each bookmark only once.
Previously, the variable 'bookmark-history' accumulated duplicate
bookmark names when bookmark features were used interactively.  This
made their history larger than necessary for frequent bookmark users.
Bookmark names are now saved uniquely.

---
*** New user option 'bookmark-bmenu-type-column-width'.
This user option controls the width of the type column on the bookmark
menu 'bookmark-bmenu-list'.  The default value is 8 which is backwards
compatible.

** Recentf

---
*** New user option 'recentf-show-messages'.
'recentf-save-list' can print a message when saving the recentf list.
The new option, if set to nil, suppresses this message.

** Saveplace

---
*** You can now regularly auto-save places.
Customize user option 'save-place-autosave-interval' to the number of
seconds between auto saving places.  For example, to save places every 5
minutes:

    M-x customize-option RET save-place-autosave-interval RET 300

Or in Elisp:

    (setopt save-place-autosave-interval (* 60 5))

If 'save-place-autosave-interval' is nil, auto saving is disabled; this
is the default.  As before, saved places are scheduled to be saved at
Emacs exit.

** Savehist

---
*** Savehist no longer saves additional variables more than once.
If you configured 'savehist-additional-variables' with variables that
were also dynamically accumulated in minibuffer history during
minibuffer use, they are now saved only once in the file specified by
'savehist-file'.  Previously, they were saved twice.

** Message

---
*** "In-Reply-To" header contains only a message id.
The "In-Reply-To" header created when replying to a message now contains
only the originating message's id, conforming to RFC 5322.  The previous
behavior included additional information about the originating message.
The new variable 'message-header-use-obsolete-in-reply-to', nil by
default, can be set to a non-nil value to restore the previous behavior.

** Gnus

---
*** Replying to icalendar events now supports specifying a comment.
When called with a prefix argument, accepting, declining, or tentatively
accepting an icalendar event will prompt for a comment to add to the
response.

** Sieve

+++
*** New keybinding to refresh buffer in 'sieve-manage-mode'.
'sieve-refresh-scriptlist' is now bound to 'g' to refresh the contents
of the current sieve buffer.

** Button

+++
*** New function 'unbuttonize-region'.
It removes all the buttons in the specified region.

+++
*** Disabling 'button-mode' now removes all buttons in the current buffer.

** Shell

*** New command to complete the shell history.
'comint-complete-input-ring' ('C-x <up>') is like 'minibuffer-complete-history'
but completes on comint inputs.

---
*** 'ansi-osc-directory-tracker' now respects remote directories.
Remote directories are now retained when changes to 'default-directory'
are detected by this filter.  For example, "/ssh:hostname:/home/username"
would have been stripped to just "/home/username" before.

** Eshell

---
*** New interactive command 'eshell-clear'.
This command scrolls the screen so that only the current prompt is
visible, optionally erasing all the previous input/output as well.
Previously, the Eshell built-in command 'eshell/clear' supported this
(e.g., to call it via 'M-x'), but this new command behaves more
consistently if you have a partially-typed command at the Eshell prompt.

---
*** New user option 'eshell-command-async-buffer'.
This option lets you tell 'eshell-command' how to respond if its output
buffer is already in use by another invocation of 'eshell-command', much
like 'async-shell-command-buffer' does for 'shell-command'.  By default,
this will prompt for confirmation before creating a new buffer when
necessary.  To restore the previous behavior, set this option to
'confirm-kill-process'.

+++
*** 'eshell-execute-file' is now an interactive command.
Interactively, this now prompts for a script file to execute.  With the
prefix argument, it will also insert any output into the current buffer
at point.

+++
*** 'eshell-command' and 'eshell-execute-file' can now set where stderr goes.
These functions now take an optional ERROR-TARGET argument to control
where to send the standard error output.  See the "(eshell) Entry
Points" node in the Eshell manual for more details.

+++
*** You can now loop over ranges of integers with the Eshell 'for' command.
When passing a range like 'BEGIN..END' to the Eshell 'for' command,
Eshell will now iterate over each integer between BEGIN and END, not
including END.

+++
*** Conditional statements in Eshell now use an 'else' keyword.
Eshell now prefers the following form when writing conditionals:

    if {conditional} {true-subcommand} else {false-subcommand}

The old form (without the 'else' keyword) is retained for compatibility.

+++
*** You can now chain conditional statements in Eshell.
When using the newly-preferred conditional form in Eshell, you can now
chain together multiple 'if'/'else' statements.  For more information,
see "(eshell) Control Flow" in the Eshell manual.

+++
*** Eshell's built-in 'wait' command now accepts a timeout.
By passing '-t' or '--timeout', you can specify a maximum time to wait
for the processes to exit.  Additionally, you can now wait for external
processes by passing their PIDs.

---
*** New hook 'eshell-after-initialize-hook'.
This hook runs after an Eshell session has been fully initialized,
immediately before running 'eshell-post-command-hook' for the first
time.

+++
*** Improved history Isearch.
History Isearch in Eshell is reworked.  Two new commands
'eshell-isearch-backward-regexp' and 'eshell-isearch-forward-regexp' are
added for incrementally searching through the input history.
'eshell-isearch-backward-regexp' is bound to 'M-r' by default, and 'M-s'
is freed for normal search commands.  If you would like to restore the
previous key-bindings for the non-incremental search commands, put in
your configuration:

    (with-eval-after-load 'em-hist
      (keymap-set eshell-hist-mode-map "M-r"
                  #'eshell-previous-matching-input)
      (keymap-set eshell-hist-mode-map "M-s"
                  #'eshell-next-matching-input))

+++
*** New user option 'eshell-history-isearch'.
When 'eshell-history-isearch' is nil (the default), Isearch commands
search in the buffer contents.  If you customize it to t, those commands
only search in input history.  If you customize it to the symbol 'dwim',
those commands search in input history only when the point is after the
last prompt.

+++
** Mail Utils

*** New user option 'mail-re-regexps'.
This contains the list of regular expressions used to match "Re:" and
international variants of it when modifying the Subject field in
replies.

+++
** Rmail

*** 'rmail-re-abbrevs' default value is now derived from 'mail-re-regexps'.
'mail-re-regexps' is a new user option that is easier to customize than
'rmail-re-abbrevs'.  'rmail-re-abbrevs' is still honored if it was
already set.

+++
** Message

*** 'message-subject-re-regexp' default value is now derived from 'mail-re-regexps'.
'mail-re-regexps' is a new user option that is easier to customize than
'message-subject-re-regexp'.  'message-subject-re-regexp' is still
honored if it was already set.

*** 'message-strip-subject-re' now matches case-insensitively.

** SHR

+++
*** SHR now slices large images into rows.
Sliced images allow for more intuitive scrolling up/down by letting you
scroll past each slice, instead of jumping past the entire image.
Previously, SHR sliced images when zoomed to their original size, no
matter how large or small that was.  Now, SHR slices any images taller
than 'shr-sliced-image-height'.  For more information, see the "(eww)
Advanced" node in the EWW manual.

---
*** You can now customize the image zoom levels to cycle through.
By customizing 'shr-image-zoom-levels', you can change the list of zoom
levels that SHR cycles through when calling 'shr-zoom-image'.

---
*** New user option 'shr-fill-text'.
When 'shr-fill-text' is non-nil (the default), SHR will fill text
according to the width of the window.  If you customize it to nil, SHR
will leave the text as-is; in that case, EWW will automatically enable
'visual-line-mode' when displaying a page so that long lines are
visually wrapped at word boundaries.

** EWW

---
*** EWW now enables 'visual-wrap-prefix-mode' when 'shr-fill-text' is nil.
By default, 'shr-fill-text' is t, and EWW fills the text according to
the width of the window.  If you customize 'shr-fill-text' to nil, EWW
will now automatically turn on 'visual-wrap-prefix-mode' in addition to
'visual-line-mode', so that long lines are wrapped at word boundaries
near window edge and the continuation lines are indented using prefixes
computed from surrounding context.

---
*** New user option 'eww-guess-content-type-functions'.
The value is a list of functions that EWW should call to determine the
content-type of Web pages which don't have a valid 'Content-Type'
header.  The default value is a function that considers a page with an
HTML 'doctype' declaration to have context-type "text/html".

** CC mode

+++
*** New type of 'c-offsets-alist' element.
The 'cdr' of such an alist element may now be a syntactic symbol.  A
source line with a syntactic element whose symbol is the 'car' of that
alist element is indented as though it were the 'cdr'.

+++
*** Enums now have their own syntactic symbols.
The new symbols 'enum-open', 'enum-close', 'enum-intro' and
'enum-entry' are used in the analysis of enum constructs.  Previously
they were given 'brace-list-open', etc.  These are fully described in
the "(ccmode) Enum Symbols" node of the CC mode manual.

+++
*** Enums are now, by default, indented like classes, not brace-lists.
To get the old behavior back, add an element '(enum-open
. brace-list-open)' to 'c-offsets-alist' in your CC mode style, or amend
'c-offsets-alist' likewise in any of the other ways detailed in the
"(ccmode) Config Basics" node of the CC mode manual.

** Go-ts mode

+++
*** New unit test commands.
Three new commands are now available to run unit tests.

The 'go-ts-mode-test-function-at-point' command runs the unit test at
point.  If a region is active, it runs all the unit tests under the
region.  It is bound to 'C-c C-t t' in 'go-ts-mode'.

The 'go-ts-mode-test-this-file' command runs all unit tests in the current
file.  It is bound to 'C-c C-t f' in 'go-ts-mode'.

The 'go-ts-mode-test-this-package' command runs all unit tests under the
package of the current buffer.  It is bound to 'C-c C-t p' in 'go-ts-mode'.

The 'go-ts-mode-build-tags' user option is available to set a list of
build tags for the test commands.

The 'go-ts-mode-test-flags' user option is available to set a list of
additional flags to pass to the go test command line.

** C-ts mode

+++
*** New user option 'c-ts-mode-enable-doxygen'.
By default, this is nil, and the Doxygen comment blocks in C/C++ source
are highlighted like other comments.  When non-nil, Doxygen comment
blocks are syntax-highlighted if the Doxygen grammar library is
available.

** Java-ts mode

+++
*** New user option 'java-ts-mode-enable-doxygen'.
By default, this is nil, and the Doxygen comment blocks in Java source
are highlighted like other comments.  When non-nil, Doxygen comment
blocks are syntax-highlighted if the Doxygen grammar library is
available.

** Emacs Lisp mode

---
*** Checkdoc no longer warns about missing footer lines in some cases.
Emacs Lisp libraries have traditionally ended with a footer line
(sometimes referred to as "terminating comment").  Their purpose was to
easily detect files that had been truncated in transit on ancient and
less reliable connections:

    ;; some-cool-package.el ends here

'checkdoc' will no longer warn if that line is missing for packages that
explicitly only support Emacs 30.1 or later, as specified in the
"Package-Requires" header.  The reason for keeping the warning for
packages that support earlier versions of Emacs is that package.el in
those versions can't install packages where that line is missing.

This change affects both 'M-x checkdoc' and the corresponding flymake
backend.

---
*** Checkdoc will now flag incorrect formatting in warnings.
This affects calls to 'warn', 'lwarn', 'display-warning', and
'message-box'.

---
*** New user option 'checkdoc-allow-quoting-nil-and-t'.
Customizing this option to a non-nil value stops checkdoc from warning
for docstrings where symbols 'nil' and 't' are in quotes.

---
*** The default of 'checkdoc-verb-check-experimental-flag' is now nil.
In most cases, having it enabled leads to a large amount of false
positives.

** DocView

---
*** Dedicated buffer for plain text contents.
When switching to the plain text contents with 'doc-view-open-text',
DocView now creates a dedicated buffer to display it.  'C-c C-c' gets you
back to real DocView buffer if it still exists.

+++
*** New commands to save and restore pages in buffer-local registers.
Docview can store the current page to buffer-local registers with the new
command 'doc-view-page-to-register' (bound to 'm'), and later the stored
page can be restored with 'doc-view-jump-to-register' (bound to ''').

+++
*** Docview can generate imenu indices for DjVu and ODF documents.
When the 'djvused' program is available, Docview can now generate an imenu
index for DjVu files from its outline.  Indices for Open Document Format
(ODF) files as used by OpenOffice and LibreOffice are generated using
the 'mutool' program after their initial conversion to PDF format.  The
name of the 'djvused' program can be customized by changing the user
option 'doc-view-djvused-program'.

** Ispell

---
*** The default value of 'ispell-help-timeout' has changed.
The default value is now 30 seconds, as the old value was too short to
allow reading the help text.

** Flyspell

---
*** New user option 'flyspell-delay-use-timer'.
By default, Flyspell waits after so-called "delayed" commands by calling
'sit-for'.  If you customize this option to non-nil, Flyspell instead
sets up a timer to perform spell-checking after a short delay, which
allows idle timers and other code to run during this delay period.  We
consider making this behavior the default in a future Emacs version, so
we invite Flyspell users to enable this new option and report issues.

** Tramp

+++
*** Connection method "kubernetes" supports now optional namespace.
The host name for Kubernetes connections can be of kind
[CONTAINER.]POD[%NAMESPACE], in order to specify the namespace to be
used.  This overrides the setting in 'tramp-kubernetes-namespace', if
any.

+++
*** Different proxies for the same destination host name can be specified.
A typical example are docker containers, which run on different hosts
under the same docker name.  When the user option
'tramp-show-ad-hoc-proxies' is non-nil, such ad-hoc multi-hop file names
can be used in parallel.  Example: on both remote hosts "host1" and
"host2" there is a docker container "name", respectively:

    /ssh:user1@host1|docker:name:
    /ssh:user2@host2|docker:name:

This feature is experimental.

** Diff

---
*** New command 'diff-kill-ring-save'.
This command copies to the 'kill-ring' a region of text modified
according to diffs in the current buffer, but without applying the diffs
to the original text.  If the selected range extends a hunk, the
command attempts to look up and copy the text in-between the hunks.

+++
*** New command 'diff-revert-and-kill-hunk' bound to 'C-c M-r'.
This command reverts the hunk at point (i.e., applies the reverse of the
hunk), and then removes the hunk from the diffs.
This is useful to undo or revert changes, committed and uncommitted, when
you are in buffers generated by 'C-x v =' and 'C-x v D'.

---
*** 'diff-file-prev' and 'diff-hunk-prev' always move to start of header.
Previously, 'diff-file-prev' and 'diff-hunk-prev' would move when point
is after the corresponding file or hunk header, but not when inside it.
Now they will always move to the start of the current header.

+++
*** New command 'diff-delete-other-hunks' bound to 'C-c RET n'.
This command deletes all hunks other than the current hunk.  It is
useful to prepare a "*vc-diff*" buffer for committing a single hunk.
When the region is active, it deletes all hunks that the region does not
overlap.

*** 'diff-apply-hunk' now supports creating and deleting files.

---
*** 'vc-version-diff' and 'vc-root-version-diff' changed default for REV1.
They suggest the previous revision as the default for REV1, not the last
one as before.  This makes them different from 'vc-diff' and
'vc-root-diff' when those are called without a prefix argument.

** PHP-ts mode

---
*** 'php-ts-mode-run-php-webserver' can now accept a custom "php.ini" file.
You can use the new optional argument CONFIG when calling
'php-ts-mode-run-php-webserver' to pass an alternative "php.ini" file to
the built-in Web server.  Interactively, when invoked with a prefix
argument, 'php-ts-mode-run-php-webserver' prompts for the config file as
well as for other connection parameters.

** Rust-ts mode

---
*** New user option 'rust-ts-mode-fontify-number-suffix-as-type'.
Rust number literals may have an optional type suffix.  When this option
is non-nil, this suffix is fontified using 'font-lock-type-face'.

** Ediff

+++
*** Ediff's copy commands now apply to all changes with 'C-u' prefix.
The Ediff copy commands, bound to 'a', 'b', 'ab', etc., now copy all
changes when supplied with a universal prefix argument via 'C-u':

- 'C-u a' copies all changes from buffer A to buffer B (in 2-way diff)
  or to buffer C (in 3-way diff or merge).
- 'C-u b' copies all changes from buffer B to buffer A (in 2-way diff)
  or to buffer C (in 3-way diff or merge).
- 'C-u a b' copies all changes from buffer A to buffer B.
- 'C-u b a' copies all changes from buffer B to buffer A.
- 'C-u a c' copies all changes from buffer A to buffer C.
- 'C-u b c' copies all changes from buffer B to buffer C.
- 'C-u c a' copies all changes from buffer C to buffer A.
- 'C-u c b' copies all changes from buffer C to buffer B.

** Dired

+++
*** New user option 'dired-check-symlinks' allows disabling validity checks.
Dired uses 'file-truename' to check symbolic link validity when
fontifying them, which can be slow for remote directories.  Setting
'dired-check-symlinks' to nil disables these checks.  Defaults to t, can
be set as a connection-local variable.

---
*** New user option 'dired-hide-details-hide-absolute-location'.
When Dired's 'dired-hide-details-mode' is enabled, also hide the
'default-directory' absolute location, typically displayed as the first
line in a Dired buffer.

With 'dired-hide-details-hide-absolute-location':

    project: (100 GiB available)

Without 'dired-hide-details-hide-absolute-location':

    /absolute/path/to/my/important/project: (100 GiB available)

---
*** Clicking on base name of directory reverts buffer.
When 'dired-make-directory-clickable' is non-nil, clicking on the base
name of the directory now reverts the Dired buffer.

** Grep

+++
*** Grep results can be edited to reflect changes in the originating file.
Like Occur Edit mode, typing 'e' in the "*grep*" buffer will now make
the 'grep' results editable.  The edits will be reflected in the buffer
visiting the originating file.  Typing 'C-c C-c' will leave the Grep
Edit mode.

** Time Stamp

---
*** 'time-stamp' can up-case, capitalize and down-case date words.
This control can be useful in languages in which days of the week and/or
month names are capitalized only at the beginning of a sentence.  For
details, see the built-in documentation for user option 'time-stamp-format'.

Because this feature is new in Emacs 31.1, do not use it in the local
variables section of any file that might be edited by an older version
of Emacs.

---
*** Some historical 'time-stamp' conversions now warn.
'time-stamp-pattern' and 'time-stamp-format' had quietly accepted
several 'time-stamp' conversions (e.g., "%:y") that have been deprecated
since Emacs 27.1.  These now generate a warning with a suggested
migration.

Merely having '(add-hook 'before-save-hook 'time-stamp)'
in your Emacs init file does not expose you to this change.
However, if you set 'time-stamp-format' or 'time-stamp-pattern'
with a file-local variable, you may be asked to update the value.

** TeX modes

+++
*** New Xref backend for TeX modes.
The new backend ('tex-etags') is on by default, and improves the
functionality of the standard 'xref' commands in TeX buffers.  You can
restore the standard 'etags' backend with the 'M-x xref-etags-mode'
toggle.

** BibTeX mode

---
*** New user options facilitate customization of BibTeX and biblatex entries.
Entry definitions via the user options 'bibtex-BibTeX-aux-entry-alist',
'bibtex-biblatex-aux-entry-alist', 'bibtex-BibTeX-aux-opt-alist', and
'bibtex-biblatex-aux-opt-alist' take precedence over
'bibtex-BibTeX-entry-alist' and 'bibtex-biblatex-entry-alist'.
These user options now support the definition of aliases that inherit
the definition of another entry.

---
*** 'bibtex-user-optional-fields' has been renamed to 'bibtex-aux-opt-alist'.
The old name is an obsolete alias.

---
*** 'bibtex-include-OPTkey' is now obsolete and its default is nil.
Use 'bibtex-aux-opt-alist' instead.

---
*** New user option 'bibtex-entry-ask-for-key'.
When enabled, 'bibtex-entry' asks for a key.

---
*** 'bibtex-string-file-path' and 'bibtex-file-path' are lists of directories.
For backward compatibility, considered obsolete, these user options
may still be strings with colon separated lists of directories.

** Midnight mode

---
*** Change for activating the mode.
Putting '(require 'midnight)' in your init file no longer activates the
mode.  Now, one needs to say '(midnight-mode +1)' instead.

** Python mode

---
*** Prefer "python" for 'python-interpreter' and 'python-shell-interpreter'.
On recent versions of mainstream GNU/Linux distributions, "python"
either does not exist or it points to Python 3.  These user options now
default to using "python", falling back to "python3" if it does not
exist.  If "python" points to Python 2 on your system, you now have to
customize these variables to "python3" if you want to use Python 3
instead.

---
*** Python 2 support is now optional and disabled by default.
Since Python 2 EOL was over 5 years ago, this release removes Python
2-only builtins such as "file" from the default highlighting in
'python-mode' and 'python-ts-mode'.  If you would like them highlighted,
customize the new user option 'python-2-support' to a non-nil value and
restart Emacs.

---
*** Support of 'electric-layout-mode' added.

** Tmm Menubar

---
*** A new shortcut to navigate to previous menu.
The hardcoded '^' shortcut gets you back to the previous menu.

---
*** New user option 'tmm-shortcut-inside-entry'.
When non-nil, highlight the character shortcut in the menu entry's
string instead of preprending it and 'tmm-mid-prompt' to said entry.

** Foldout

---
*** New command 'foldout-widen-to-current-fold'.
This command widens the view to the current fold level when in a fold,
or behaves like 'widen' if not in a fold.

** MPC

---
*** New user option 'mpc-notifications'.
When non-nil, MPC (the Emacs front-end to Music Player Daemon) displays
a desktop notification when the song changes, using
'notifications-notify'.  The notification's title and body can be
customized using the new user options 'mpc-notifications-title' and
'mpc-notifications-body'.

---
*** New user option 'mpc-crossfade-time'.
When non-nil, MPC will crossfade between songs for the specified number
of seconds.  Crossfading can be toggled using the command
'mpc-toggle-crossfade' or from the MPC menu.

---
*** New command 'mpc-describe-song'.
This command displays information about the currently playing song or
song at point in the "*MPC-Songs*" buffer.  The list of tags to display
can be customized using the new user option 'mpc-song-viewer-tags' and
the appearance of the list with the new faces 'mpc-table-key',
'mpc-table-value', and 'mpc-table-empty'.

---
*** New command 'mpc-server-stats'.
This command displays information about the connected MPD server.  The
appearance of the list can be customized with the new faces
'mpc-table-key' and 'mpc-table-value'.

** VC

---
*** Using 'e' from Log View mode to modify change comments now works for Git.

---
*** New user option 'vc-allow-rewriting-published-history'.
Some VCS commands can change your copy of published change history
without warning.  In VC we try to detect before that happens, and stop.
You can customize this option to permit rewriting history even though
Emacs thinks it is dangerous.

---
*** 'vc-clone' is now an interactive command.
When called interactively, 'vc-clone' now prompts for the remote
repository address, and the directory into which to clone the
repository.  It tries to automatically determine the VC backend for
cloning, or prompts for that, too.

---
*** 'vc-clone' now accepts an optional argument OPEN-DIR.
When the argument is non-nil, the function switches to a buffer visiting
the directory into which the repository was cloned.

---
*** 'C-x v u' ('vc-revert') now works on directories listed in VC Directory.
Reverting a directory means reverting changes to all files inside it.

** Package

+++
*** No longer warn if a package has no footer line.
package.el no longer warns for packages without a "footer line", which
is the line that usually appears at the very end of an Emacs Lisp file:

    ;;; FILENAME ends here

---
*** New optional argument to 'package-autoremove'.
An optional argument NOCONFIRM has been added to 'package-autoremove'.
If it is non-nil, or when invoked with a prefix argument,
'package-autoremove' will not prompt the user for confirmation before
removing packages.

---
*** New prefix argument for 'package-install-selected-packages'.
When invoked with a prefix argument, 'package-install-selected-packages'
will not prompt the user for confirmation before installing packages.

---
*** 'package-refresh-contents' runs asynchronously.
Refreshing the package index will no longer block when invoked
interactively.

+++
*** package-x.el is now obsolete.

** Xref

---
*** Xref commands that jump to some location use 'display-buffer'.
The commands that jump to some location use 'display-buffer' and specify
the category 'xref-jump'.  As a result, you can customize how the
destination window is chosen using 'display-buffer-alist'.  Example:

    (setq display-buffer-alist '(((category . xref-jump)
                                  (display-buffer-reuse-window
                                   display-buffer-use-some-window)
                                  (some-window . mru))))

** Autorevert

+++
*** New variable 'inhibit-auto-revert-buffers'.
While a buffer is member of this variable, a list of buffers,
auto-reverting of this buffer is suppressed.

+++
*** New macro 'inhibit-auto-revert'.
This macro adds the current buffer to 'inhibit-auto-revert-buffers',
runs its body, and removes the current buffer from
'inhibit-auto-revert-buffers' afterwards.

** Strokes

--
** 'strokes-mode' no longer demands the presence of a mouse.
'strokes-mode' now permits itself to be enabled if no mouse is
connected, to facilitate enabling 'strokes-mode' in sessions where the
availability of a mouse device varies during execution (as is frequently
observed on Android).

** Yank media

+++
*** 'yank-media' now auto-selects the most preferred MIME type.
Major-mode authors can customize the variables
'yank-media-autoselect-function' and/or 'yank-media-preferred-types' to
change the selection rules.

** Miscellaneous

---
*** cdl.el is now obsolete.
Use 'shell-command' and 'shell-command-on-region' instead.

---
*** kermit.el is now obsolete.


* New Modes and Packages in Emacs 31.1

** New major modes based on the tree-sitter library

*** New major mode 'markdown-ts-mode'.
A major mode based on the tree-sitter library for editing Markdown files.

*** New major mode 'mhtml-ts-mode'.
An optional major mode based on the tree-sitter library for editing HTML
files.  This mode handles indentation, fontification, and commenting for
embedded JavaScript and CSS.

---
*** New major mode 'go-work-ts-mode'.
A major mode based on the tree-sitter library for editing "go.work"
files.  If tree-sitter is properly set-up by the user, it can be
enabled for files named "go.work".


* Incompatible Lisp Changes in Emacs 31.1

** Nested backquotes are not supported any more in Pcase patterns.

---
** The obsolete variable 'redisplay-dont-pause' has been removed.

** The 'rx' category name 'chinese-two-byte' must now be spelled correctly.
An old alternative name (without the first 'e') has been removed.

+++
** 'read-directory-name' now accepts an optional PREDICATE argument.

+++
** 'text-property-default-nonsticky' is now buffer-local.
This variable now becomes buffer-local when set.  Use 'setq-default' in
(the unlikely) case you want to change the global value.

---
** All the digit characters now have the 'digit' category.
All the characters whose Unicode general-category is Nd now have the
'digit' category, whose mnemonic is '6'.  This includes both ASCII and
non-ASCII digit characters.

---
** All the symbol characters now have the 'symbol' category.
All the characters that belong to the 'symbol' script (according to
'char-script-table') now have the 'symbol' category, whose mnemonic is
'5'.

** Some libraries obsolete since Emacs 24.4 and 24.5 have been removed:
cc-compat.el, info-edit.el, meese.el, otodo-mode.el, rcompile.el,
sup-mouse.el, terminal.el, vi.el, vip.el, ws-mode.el, and yow.el.

+++
** 'if-let' and 'when-let' are now obsolete.
Use 'if-let*', 'when-let*' and 'and-let*' instead.

This effectively obsoletes the old '(if-let (SYMBOL SOMETHING) ...)'
single binding syntax, which we'd kept only for backwards compatibility.

---
** The Eshell 'pwd' command now expands the directory name on all systems.
This ensures that user directories are properly expanded to their full
name.  Previously, Eshell only did this for MS-Windows systems. To
restore the old behavior, you can set 'eshell-pwd-convert-function' to
'identity'.

---
** The rx 'eval' form now uses the current elisp dialect for evaluation.
Previously, its argument was always evaluated using dynamic binding.


* Lisp Changes in Emacs 31.1

---
** You can change the default value of 'lexical-binding'.
While the default is still the use dynamic binding dialect of ELisp
in those places that don't explicitly set 'lexical-binding' you can
change it globally with:

    (set-default-toplevel-value 'lexical-binding t)

+++
*** New macros 'incf' and 'decf'.
They increment or decrement the value stored in a variable (a symbol),
or in a generalized variable.

+++
** New functions 'plusp' and 'minusp'.
They return non-nil if a number is positive or negative, respectively,
and signal an error if they are given a non-number.

+++
** New functions 'oddp' and 'evenp'.
They return non-nil if an integer is odd or even, respectively, and
signal an error if they are given a non-integer.

** Time & Date

+++
*** 'seconds-to-string' supports new formatting options.
Optional arguments are provided to produce human-readable time-duration
strings in a variety of formats, for example "6 months 3 weeks" or "5m
52.5s".

+++
** The function 'purecopy' is now an obsolete alias for 'identity'.

** New function 'native-compile-directory'.
This function natively-compiles all Lisp files in a directory and in its
sub-directories, recursively, which were not already natively-compiled.

---
** New function 'color-blend'.
This function takes two RGB lists and optional ALPHA and returns an RGB
list whose elements are blended in linear space proportional to ALPHA.

+++
** The 'defcustom' ':local' keyword can now be 'permanent-only'.
This means that the variable's 'permanent-local' property is set to t,
without marking it as automatically buffer-local.

---
** The obsolete face attribute ':reverse-video' has been removed.
Use ':inverse-video' instead.

+++
** Support interactive D-Bus authorization.
A new ':authorizable t' parameter has been added to 'dbus-call-method'
and 'dbus-call-method-asynchronously' to allow the user to interactively
authorize the invoked D-Bus method (for example via polkit).

** The customization group 'wp' has been removed.
It has been obsolete since Emacs 26.1.  Use the group 'text' instead.

** Changes in tree-sitter modes

+++
*** Indirect buffers can have their own parser list.
Before, indirect buffers share their base buffer’s parser list and
parsers.  Now they can have their own parser list.

+++
*** New variable 'treesit-language-remap-alist'.
This variable allows a user to remap one language into another, such
that creating a parser for language A actually creates a parser for
language B.  By extension, any font-lock rules or indentation rules for
language A will be applied to language B instead.

This is useful for reusing font-lock rules and indentation rules of
language A for language B, when language B is a strict superset of
language A.

+++
*** New accessor functions for each setting in 'treesit-font-lock-settings'.
Now users can access a setting's query, feature, enable flag, and
override flag by 'treesit-font-lock-setting-query',
'treesit-font-lock-setting-feature', 'treesit-font-lock-setting-enable',
and 'treesit-font-lock-setting-override'.

*** New tree-sitter thing 'list'.
Unlike the existing thing 'sexp' that defines both lists and atoms,
'list' defines only lists to be navigated by 'forward-sexp'.
The new function 'treesit-forward-sexp-list' uses 'list'
to move across lists.  But to move across atoms inside the list
it uses 'forward-sexp-default-function'.

*** New tree-sitter based functions for moving by lists.
If a major mode defines 'list' in 'treesit-thing-settings',
tree-sitter setup for these modes sets 'forward-list-function' to
'treesit-forward-list', 'up-list-function' to 'treesit-up-list', and
'down-list-function' to 'treesit-down-list'.  This enables the
'forward-list', 'up-list', and 'down-list' motion commands for those
modes.

*** Tree-sitter enabled modes now properly support 'show-paren-mode'.
They do that by letting 'show-paren-mode' use the results of parsing by
the tree-sitter library.  The new function 'treesit-show-paren-data' is
used to communicate the tree-sitter parsing results to
'show-paren-mode'.

*** Tree-sitter enabled modes now properly support 'hs-minor-mode'.
All commands from hideshow.el can selectively display blocks
defined by the new tree-sitter thing 'list'.

*** New tree-sitter thing 'comment'.
The new variable 'forward-comment-function' is set to the new function
'treesit-forward-comment' if a major mode defines the thing 'comment'.

+++
*** New function 'treesit-language-display-name'.
This new function returns the display name of a language given the
language symbol.  For example, 'cpp' is translated to "C++".  A new
variable 'treesit-language-display-name-alist' holds the translations of
language symbols where that translation is not trivial.

*** New function 'treesit-merge-font-lock-feature-list'.
This function merges two tree-sitter font-lock feature lists.  Returns a
new font-lock feature list with no duplicates in the same level.  It can
be used to merge font-lock feature lists in a multi-language major mode.

*** New function 'treesit-replace-font-lock-feature-settings'.
Given two tree-sitter font-lock settings, it replaces the feature in the
second font-lock settings with the same feature in the first font-lock
settings.  In a multi-language major mode it is sometimes necessary to
replace features from one of the major modes, with others that are
better suited to the new multilingual context.

*** New function 'treesit-simple-indent-modify-rules'.
Given two tree-sitter indent rules, it replaces, adds, or prepends rules
in the old rules with new ones, then returns the modified rules.  In a
multi-language major mode it is sometimes necessary to modify rules from
one of the major modes to better suit the new multilingual context.

+++
*** New command 'treesit-explore'.
This command replaces 'treesit-explore-mode'.  It turns on
'treesit-explore-mode' if it’s not on, and pops up the explorer buffer
if it’s already on.

+++
*** 'treesit-explore-mode' now supports local parsers.
Now 'treesit-explore-mode' (or 'treesit-explore') prompts for a parser
rather than a language, and it’s now possible to select a local parser
at point to explore.

+++
*** New variable 'treesit-aggregated-simple-imenu-settings'.
This variable allows major modes to setup Imenu for multiple languages.

+++
*** New variable 'treesit-aggregated-outline-predicate'.
This variable allows major modes to setup 'outline-minor-mode'
for multiple languages.

*** New function 'treesit-simple-indent-add-rules'.
This new function makes it easier to customize indent rules for
tree-sitter modes.

*** New variable 'treesit-simple-indent-override-rules'.
Users can customize this variable to add simple custom indentation rules
for tree-sitter major modes.

+++
** New optional BUFFER argument for 'string-pixel-width'.
If supplied, 'string-pixel-width' will use any face remappings from
BUFFER when computing the string's width.

---
** New macro 'with-work-buffer'.
This macro is similar to the already existing macro 'with-temp-buffer',
except that it does not allocate a new temporary buffer on each call,
but tries to reuse those previously allocated (up to a number defined by
the new variable 'work-buffer-limit', which defaults to 10).

+++
** 'date-to-time' now defaults to local time.
The function now assumes local time instead of Universal Time when
its argument lacks explicit time zone information.  This has been the
de-facto behavior since Emacs 24 although documentation said otherwise.
Also, the fallback on 'timezone-make-date-arpa-standard' has been
removed because its supported date styles can be handled by
'parse-time-string'.  To restore the previously documented behavior,
specify "+0000" or "Z" as the time zone in the argument.

---
** The 'min-width' property is now supported for overlays as well.
This 'display' property was previously supported only as text property.
Now overlays can also have this property, with the same effect for the
text "covered" by the overlay.

+++
** New macro 'cond*'.
The new macro 'cond*' is an alternative to 'cond' and 'pcase'.
Like them, it can be used to define several clauses, each one with its
own condition; the first clause that matches will cause its body to be
evaluated.
'cond*' can use Pcase's pattern matching syntax and also provides
another pattern matching syntax that is different from that of 'pcase',
which some users might find less cryptic.
See the Info node "(elisp) cond* Macro" for details.

---
** New function 'shell-command-do-open'.
This lets a Lisp program access the core functionality of the
'dired-do-open' command.  It opens a file or files using an external
program, choosing the program according to the operating system's
conventions.

+++
** 'make-vtable' can create an empty vtable.
It is now possible to create a vtable without data, by leaving the
':objects' list empty, or by providing an ':objects-function' that
(initially) produces no data.  In such a case, it is necessary to
provide a ':columns' spec, so that the number of columns and their
widths can be determined.  Column widths can be set explicitly, or they
will be calculated based on the window width.

+++
** New symbol property 'repeat-continue' for 'repeat-mode'.
A command with this symbol property whose value is a list of repeat
maps will not activate the repeat map in 'repeat-mode'.  It will only
continue the already activated repeating sequence.  Also 'defvar-keymap'
supports a new keyword ':continue' with a list of commands that
only continue the active repeating sequence.

** New function 'completion-table-with-metadata'.
It offers a more concise way to create a completion table with metadata.

+++
** 'all-completions' and 'unintern' no longer support old calling conventions.

+++
** New symbol property 'find-function-type-alist' used by 'find-function' etc.
Macros that define an object in a way that makes the object's name and
the macro call site defining the object hard to associate can add an
entry to the property 'find-function-type-alist' on the object's name to
provide instructions for finding the definition.

New convenience function 'find-function-update-type-alist' offers a
concise way to update a symbol's 'find-function-type-alist' property.

** Special Events

+++
*** New primitive 'insert-special-event'.
This function inserts the special EVENT into the input event queue.

+++
*** New event type 'sleep-event'.
This event is sent when the device running Emacs enters or leaves the
sleep state.


* Changes in Emacs 31.1 on Non-Free Operating Systems

---
** Process execution has been optimized on Android.
The run-time performance of subprocesses on recent Android releases,
where a userspace executable loader is required, has been optimized on
systems featuring Linux 3.5.0 and above.

---
** 'NSSpeechRecognitionUsageDescription' now included in "Info.plist" (macOS).
Should Emacs (or any built-in shell) invoke a process using macOS speech
recognition APIs, the relevant permission dialog is now displayed, thus
allowing Emacs users access to speech recognition utilities.

Note: Accepting this permission allows the use of system APIs, which may
send user data to Apple’s speech recognition servers.

---
** Emacs on MS-Windows now supports GUI dialogs and message boxes better.
In particular, it is now possible to show text with embedded newlines in
a dialog popped by 'message-box'.  This is supported on Windows Vista
and later versions.

---
** Emacs on MS-Windows now supports drag-n-drop of text into a buffer.
This is in addition to drag-n-drop of files, that was already
supported.  As on X, the user options 'dnd-scroll-margin' and
'dnd-indicate-insertion-point' can be used to customize the process.

---
** Emacs on MS-Windows now supports color fonts.
On Windows 8.1 and later versions Emacs now uses DirectWrite to draw
text, which supports color fonts.  This can be disabled by setting the
variable 'w32-inhibit-dwrite' to t.  Also see 'w32-dwrite-available' and
'w32-dwrite-reinit' to check availability and to configure the
DirectWrite rendering parameters.

To show color Emojis in Emacs, customize the default fontset to use a
color Emoji font installed on your system for the 'emoji' script.

+++
** Emacs on MS-Windows now supports 'yank-media'.
This command inserts clipboard data of different formats into the
current buffer, if the major mode supports it.  (Support for
'yank-media' will be unavailable on MS-Windows if Emacs was configured
'--without-native-image-api'.)

---
** Images on MS-Windows now support the ':transform-smoothing' flag.
Transformed images are smoothed using the bilinear interpolation by
means of the GDI+ library.

---
** Emacs on MS-Windows now supports the ':data' keyword for 'play-sound'.
In addition to ':file FILE' for playing a sound from a file, ':data
DATA' can now be used to play a sound from memory.

---
** The MS-DOS port of Emacs now supports more recent releases of GCC and Binutils.
Accordingly, we have revised our recommendations for a suitable DJGPP
toolchain to GCC 14.2.0 and Binutils 2.35.1 in lieu of GCC 3.4.x and
Binutils 2.26.


----------------------------------------------------------------------
This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.


Local variables:
coding: utf-8
mode: outline
mode: emacs-news
paragraph-separate: "[	 ]"
end:
