emacs/etc/NEWS

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

Copyright (C) 2021 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 29.

See file HISTORY for a list of GNU Emacs versions and release dates.
See files NEWS.28, NEWS.27, ..., 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 29.1

** Emacs now installs the ".pdmp" file using a unique fingerprint in the name.
The file is typically installed using a file name akin to
"...dir/libexec/emacs/29.1/x86_64-pc-linux-gnu/emacs-<fingerprint>.pdmp".
If a constant file name is required, the file can be renamed to
"emacs.pdmp", and Emacs will find it during startup anyway.


* Startup Changes in Emacs 29.1

+++
** Emacs now has a '--fingerprint' option.
This will output a string identifying the current Emacs build.

+++
** New hook 'after-pdump-load-hook'.
This is run at the end of the Emacs startup process, and it meant to
be used to reinitialize structures that would normally be done at load
time.


* Changes in Emacs 29.1

** Help

---
*** 'C-h b' uses outlining by default.
Set 'describe-bindings-outline' to nil to get the old behaviour.

---
*** Jumping to function/variable source now saves mark before moving point.
Jumping to source from "*Help*" buffer moves the point when the source
buffer is already open.  Now, the old point is pushed to mark ring.

+++
*** New key bindings in *Help* buffers: 'n' and 'p'.
These will take you (respectively) to the next and previous "page".

** Outline Minor Mode

+++
*** New user option 'outline-minor-mode-use-buttons'.
If non-nil, Outline Minor Mode will use buttons to hide/show outlines
in addition to the ellipsis.

---
*** New user option 'outline-minor-mode-buttons'.
This is a list of pairs of open/close strings used to display buttons.

** Fonts

---
*** Emacs now supports "medium" fonts.
Emacs previously didn't distinguish between the "regular" weight and
the "medium" weight, but it now also supports the (heavier) "medium"
weight.

+++
** Support for the WebP image format.
This support is built by default when the libwebp library is
available.  To disable it, use the '--without-webp' configure flag.
Image specifiers can now use ':type webp'.

** Windows

+++
*** 'display-buffer' now can set up the body size of the chosen window.
For example, an alist entry as '(window-width . (body-columns . 40))'
will make the body of the chosen window 40 columns wide.


* Editing Changes in Emacs 29.1

---
** Indentation of 'cl-flet' and 'cl-labels' has changed.
These forms now indent like this:

    (cl-flet ((bla (x)
		(* x x)))
      (bla 42))

This change also affects 'cl-macrolet', 'cl-flet*' and
'cl-symbol-macrolet'.

+++
** New user option 'translate-upper-case-key-bindings'.
This can be set to nil to inhibit translating upper case keys to lower
case keys.

+++
** New command 'ensure-empty-lines'.
This command increases (or decreases) the number of empty lines before
point.

---
*** Improved mouse behavior with auto-scrolling modes.
When clicking inside the 'scroll-margin' or 'hscroll-margin' region
the point is now moved only when releasing the mouse button.  This no
longer results in a bogus selection, unless the mouse has been
effectively dragged.

+++
** 'kill-ring-max' now defaults to 120.

---
** New user option 'yank-menu-max-items'.
Customize this option to limit the amount of entries in the menu
"Edit->Paste from Kill Menu".  The default is 60.

** show-paren-mode

+++
*** New user option 'show-paren-context-when-offscreen'.
When non-nil, if the point is in a closing delimiter and the opening
delimiter is offscreen, shows some context around the opening
delimiter in the echo area.

** Comint

+++
*** 'comint-term-environment' is now aware of connection-local variables.
The user option 'comint-terminfo-terminal' and variable
'system-uses-terminfo' can now be set as connection-local variables to
change the terminal used on a remote host.


* Changes in Specialized Modes and Packages in Emacs 29.1

** EIEIO
+++
*** 'slot-value' can now be used to read slots of 'cl-defstruct' objects

** align

---
*** Alignment in 'text-mode' has changed.
Previously, 'M-x align' didn't do anything, and you had to say 'C-u
M-x align' for it to work.  This has now been changed.  The default
regexp for 'C-u M-x align-regexp' has also been changed to be easier
for inexperienced users to use.

** eww

+++
*** New user option to automatically rename EWW buffers.
The 'eww-auto-rename-buffer' user option can be configured to rename
rendered web pages by using their title, URL, or a user-defined
function which returns a string.  For the first two cases, the length
of the resulting name is controlled by 'eww-buffer-name-length'.  By
default, no automatic renaming is performed.

** Help

*** New user option 'help-link-key-to-documentation'.
When this option is non-nil, key bindings displayed in the "*Help*"
buffer will be linked to the documentation for the command they are
bound to.  This does not affect listings of key bindings and
functions (such as 'C-h b').

** info-look

---
*** info-look specs can now be expanded at run time instead of a load time.
The new ':doc-spec-function' element can be used to compute the
':doc-spec' element when the user asks for info on that particular
mode (instead of at load time).

** subr-x

+++
*** New macro 'with-memoization' provides a very primitive form of memoization.

** ansi-color

---
*** Support for ANSI 256-color and 24-bit colors.
256-color and 24-bit color codes are now handled by ANSI color
filters and displayed with the specified color.

** term-mode

---
*** Support for ANSI 256-color and 24-bit colors, italic and other fonts.
Term-mode can now display 256-color and 24-bit color codes.  It can
also handle ANSI codes for faint, italic and blinking text, displaying
it with new 'term-{faint,italic,slow-blink,fast-blink}' faces.

** Xref

*** 'project-find-file' and 'project-or-external-find-file' now accept
a prefix argument which is interpreted to mean "include all files".

+++
*** New command 'xref-go-forward'.
It is bound to 'C-M-,' and jumps to the location where 'xref-go-back'
('M-,', also known as 'xref-pop-marker-stack') was invoked previously.

** File notifications

+++
*** The new command 'file-notify-rm-all-watches' removes all file notifications.

** Sql

---
*** Sql now supports sending of passwords in-process.
To improve security, if an sql product has ':password-in-comint' set
to t, a password supplied via the minibuffer will be sent in-process,
as opposed to via the command-line.

** Image-Dired

---
*** Reduce dependency on external "exiftool" command.
The 'image-dired-copy-with-exif-file-name' no longer requires an
external "exiftool" command to be available.  The user options
'image-dired-cmd-read-exif-data-program' and
'image-dired-cmd-read-exif-data-options' are now obsolete.

---
*** New command for the thumbnail buffer.
The new command 'image-dired-unmark-all-marks' has been added with a
binding in the menu.

---
*** Support Thumbnail Managing Standard v0.9.0 (Dec 2020).
This standard allows sharing generated thumbnails across different
programs.  Version 0.9.0 adds two larger thumbnail sizes: 512x512 and
1024x1024 pixels.  See the user option `image-dired-thumbnail-storage'
to use it; it is not enabled by default.

---
*** Support GraphicsMagick command line tools.
Support for the GraphicsMagick command line tool ("gm") has been
added, and is used instead of ImageMagick when it is available.

---
*** Support for bookmark.el.
The command 'bookmark-set' (bound to 'C-x r m') is now supported in
the thumbnail view, and will create a bookmark that opens the current
directory in Image-Dired.

+++
*** 'image-dired-show-all-from-dir-max-files' has been increased to 500.
This option controls asking for confirmation when starting Image-Dired
in a directory with many files.  However, Image-Dired creates
thumbnails in the background these days, so this is not as important
as it used to be, back when entering a large directory could lock up
Emacs for tens of seconds.  In addition, you can now customize this
option to nil to disable this confirmation completely.

---
*** Make 'image-dired-rotate-thumbnail-(left|right)' obsolete.
Instead, use 'M-x image-dired-refresh-thumb' to generate a new
thumbnail, or 'M-x image-rotate' to rotate the thumbnail without
updating the thumbnail file.

** Dired

---
*** New user option 'dired-make-directory-clickable'.
If non-nil (which is the default), hitting 'RET' or 'mouse-1' on
the directory components at the directory displayed at the start of
the buffer will take you to that directory.


** Exif

*** New function 'exif-field'.
This is a convenience function to extract the field data from
'exif-parse-file' and 'exif-parse-buffer'.


* New Modes and Packages in Emacs 29.1

+++
** New mode 'erts-mode'.
This mode is used to edit files geared towards testing actions in
Emacs buffers, like indentation and the like.  The new ert function
'ert-test-erts-file' is used to parse these files.


* Incompatible Lisp Changes in Emacs 29.1

** Keymap descriptions have changed.
'help--describe-command', 'C-h b' and associated functions that output
keymap descriptions have changed.  In particular, prefix commands are
not output at all, and instead of "??" for closures/functions,
"[closure]"/"[lambda]" is output.

---
** 'downcase' details have changed slightly.
In certain locales, changing the case of an ASCII-range character may
turn it into a multibyte character, most notably with "I" in Turkish
(the lowercase is "ı", 0x0131).  Previously, 'downcase' on a unibyte
string was buggy, and would mistakenly just return the lower byte of
this, 0x31 (the digit "1").  'downcase' on a unibyte string has now
been changed to downcase such characters as if they were ASCII.  To
get proper locale-dependent downcasing, the string has to be converted
to multibyte first.  (This goes for the other case-changing functions,
too.)

---
** 'def' indentation changes.
In 'emacs-lisp-mode', forms with a symbol with a name that start with
"def" have been automatically indented as if they were 'defun'-like
forms, for instance:

    (defzot 1
      2 3)

This heuristic has now been removed, and all functions/macros that
want to be indented this way have to be marked with

    (declare (indent defun))

or the like.  If the function/macro definition itself can't be
changed, the indentation can also be adjusted by saying something
like:

    (put 'defzot 'lisp-indent-function 'defun)

---
** The 'inhibit-changing-match-data' variable is now obsolete.
Instead, functions like 'string-match' and 'looking-at' now take an
optional 'inhibit-modify' argument.

---
** 'gnus-define-keys' is now obsolete.
Use 'define-keymap' instead.

---
** MozRepl has been removed from js.el.
MozRepl was removed from Firefox in 2017, so this code doesn't work
with recent versions of Firefox.

---
** The function 'image-dired-get-exif-data' is now obsolete.
Use 'exif-parse-file' and 'exif-field' instead.


* Lisp Changes in Emacs 29.1

+++
*** New function 'file-has-changed-p'.
This convenience function is useful when writing code that parses
files at run-time, and allows Lisp programs to re-parse files only
when they have changed.

---
*** New function 'font-has-char-p'.
This can be used to check whether a specific font has a glyph for a
character.

** XDG support

*** New function 'xdg-state-home' returns $XDG_STATE_HOME.
This new location, introduced in the XDG Base Directory Specification
version 0.8 (8th May 2021), "contains state data that should persist
between (application) restarts, but that is not important or portable
enough to the user that it should be stored in $XDG_DATA_HOME".

+++
** New macro 'with-delayed-message'.
This macro is like 'progn', but will output the specified message if
the body takes longer to execute than the specified timeout.

---
** New function 'funcall-with-delayed-message'.
This function is like 'funcall', but will output the specified message
is the function take longer to execute that the specified timeout.

** Locale

---
*** New variable 'current-locale-environment'.
This holds the value of the previous call to 'set-locale-environment'.

---
*** New macro 'with-locale-environment'.
This macro can be used to change the locale temporarily while
executing code.

+++
** 'define-key' now understands a new strict 'kbd' representation for keys.
The '(define-key map ["C-c M-f"] #'some-command)' syntax is now
supported, and is like the 'kbd' representation, but is stricter.  If
the string doesn't represent a valid key sequence, an error is
signalled (both when evaluating and byte compiling).

+++
** :keys in 'menu-item' can now be a function.
If so, it is called whenever the menu is computed, and can be used to
calculate the keys dynamically.

+++
** New major mode 'clean-mode'.
This is a new major mode meant for debugging.  It kills absolutely all
local variables and removes overlays and text properties.

+++
** 'kill-all-local-variables' can now kill all local variables.
If given the new optional KILL-PERMANENT argument, also kill permanent
local variables.

+++
** Third 'mapconcat' argument SEPARATOR is now optional.
An explicit nil always meant the empty string, now it can be left out.

---
** Themes can now be made obsolete.
Using 'make-obsolete' on a theme is now supported.  This will make
'load-theme' issue a warning when loading the theme.

+++
** New function 'define-keymap'.
This function allows defining a number of keystrokes with one form.

+++
** New macro 'defvar-keymap'.
This macro allows defining keymap variables more conveniently.

---
** 'kbd' can now be used in built-in, preloaded libraries.
It no longer depends on edmacro.el and cl-lib.el.

+++
** New function 'kbd-valid-p'.
The 'kbd' function is quite permissive, and will try to return
something usable even if the syntax of the argument isn't completely
correct.  The 'kbd-valid-p' predicate does a stricter check of the
syntax.

+++
** New function 'image-at-point-p'.
This function returns t if point is on a valid image, and nil
otherwise.

+++
** New function 'string-pixel-width'.
This returns the width of a string in pixels.  This can be useful when
dealing with variable pitch fonts and glyphs that have widths that
aren't integer multiples of the default font.

+++
** New function 'string-glyph-split'.
This function splits a string into a list of strings representing
separate glyphs.  This takes into account combining characters and
grapheme clusters.

---
** 'lookup-key' is more allowing when searching for extended menu items.
In Emacs 28.1, the behavior of 'lookup-key' was changed: when looking
for a menu item '[menu-bar Foo-Bar]', first try to find an exact
match, then look for the lowercased '[menu-bar foo-bar]'.

This has been extended, so that when looking for a menu item with a
symbol containing spaces, as in '[menu-bar Foo\ Bar]', first look for
an exact match, then the lowercased '[menu-bar foo\ bar]' and finally
'[menu-bar foo-bar]'.  This further improves backwards-compatibility
when converting menus to use 'easy-menu-define'.


* Changes in Emacs 29.1 on Non-Free Operating Systems

** MS-Windows

+++
*** Emacs now supports system dark mode.
On Windows 10 (version 1809 and higher) and Windows 11, Emacs will now
follow the system's dark mode: GUI frames use the appropriate light or
dark title bar and scroll bars, based on the user's Windows-wide color
settings.


----------------------------------------------------------------------
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
paragraph-separate: "[ 	]*$"
end: