GNU Emacs 28 NEWS – history of user-visible changes

1.1.1. To install the Emacs binary in a non-standard directory, use --bindir=.

1.3.1. The command kdb-macro-redisplay was renamed to kmacro-redisplay.

1.3.2. desktop-save-mode now saves the desktop in save-buffers-kill-emacs.

2.1.1. Emacs now optionally supports native compilation of Lisp files.

2.1.2. The Cairo graphics library is now used by default if present.

2.1.3. configure now warns about building with libXft support.

2.1.4. configure now warns about not using HarfBuzz if using Cairo.

2.1.5. Building without double buffering support.

2.1.6. The configure option --without-makeinfo has been removed.

2.1.7. New configure option --disable-year2038.

2.1.8. Support for building with -fcheck-pointer-bounds has been removed.

2.1.9. The ftx font backend driver has been removed.

2.1.10. Emacs no longer supports old OpenBSD systems.

2.2.1. In GTK builds, Emacs now supports startup notification.

2.2.2. Errors in kill-emacs-hook no longer prevent Emacs from shutting down.

2.2.3. Emacs now supports loading a Secure Computing filter.

2.2.4. Emacs can support 24-bit color TTY without terminfo database.

2.2.5. File names given on the command line are now be pushed onto history.

2.3.1. Emacs now supports Unicode Standard version 14.0.

2.3.2. Improved support for Emoji.

(set-fontset-font t 'emoji
                  '("My New Emoji Font" . "iso10646-1") nil 'prepend)

2.3.3. glyphless-char-display-control now applies to Variation Selectors.

2.3.4. New command execute-extended-command-for-buffer.

2.3.5. New user option read-extended-command-predicate.

2.3.6. Completion on M-x shows key bindings for commands.

2.3.7. New user option completions-detailed.

2.3.8. C-s in M-x now once again searches over completions.

2.3.9. User option completions-format supports a new value one-column.

2.3.10. New system for displaying documentation for groups of functions.

2.3.11. New minor mode context-menu-mode for context menus popped by mouse-3.

2.3.12. A new keymap for buffer actions has been added.

2.3.13. Modifiers now go outside angle brackets in pretty-printed key bindings.

2.3.14. eval-expression no longer signals an error on incomplete expressions.

2.3.15. eval-last-sexp now handles defvar'/'defcustom'/'defface specially.

2.3.16. New user option use-short-answers.

2.3.17. New user option kill-buffer-delete-auto-save-files.

2.3.18. New user option next-error-message-highlight.

2.3.19. New choice next-error-quit-window for next-error-found-function.

2.3.20. New user option file-preserve-symlinks-on-save.

2.3.21. New user option copy-directory-create-symlink.

2.3.22. New user option ignored-local-variable-values.

2.3.23. Specific warnings can now be disabled from the warning buffer.

2.3.24. ".dir-locals.el" now supports setting auto-mode-alist.

2.3.25. User option uniquify-buffer-name-style can now be a function.

2.3.26. remove-hook is now an interactive command.

2.3.27. expand-file-name now checks for null bytes in filenames.

2.3.28. Frames

• The key prefix C-x 5 5 displays next command buffer in a new frame.
  

  It's bound to the command other-frame-prefix that requests the buffer
  of the next command to be displayed in a new frame.
  

• New command clone-frame (bound to C-x 5 c).
  

  This is like C-x 5 2, but uses the window configuration and frame
  parameters of the current frame instead of default-frame-alist.
  When called interactively with a prefix arg, the window configuration
  is not cloned.
  

• Default values of frame-title-format and icon-title-format have changed.
  

  These variables are used to display the title bar of visible frames
  and the title bar of an iconified frame. They now show the name of
  the current buffer and the text "GNU Emacs" instead of the value of
  invocation-name. To get the old behavior back, add the following to
  your init file:
  

  (setq frame-title-format '(multiple-frames "%b"
                            ("" invocation-name "@" system-name)))
  

• New frame parameter drag-with-tab-line.
  

  This parameter, similar to drag-with-header-line, allows moving frames
  by dragging the tab lines of their topmost windows with the mouse.
  

• New optional behavior of delete-other-frames.
  

  When invoked with a prefix argument, delete-other-frames now
  iconifies frames, rather than deleting them.
  

• Commands set-frame-width and set-frame-height now prompt for values.
  

  These commands now prompt for the value via the minibuffer, instead of
  requiring the user to specify the value via the prefix argument.
  

2.3.29. Windows

• The key prefix C-x 4 1 displays next command buffer in the same window.
  

  It's bound to the command same-window-prefix that requests the buffer
  of the next command to be displayed in the same window.
  

• The key prefix C-x 4 4 displays next command buffer in a new window.
  

  It's bound to the command other-window-prefix that requests the buffer
  of the next command to be displayed in a new window.
  

• New command recenter-other-window, bound to S-M-C-l.
  

  Like recenter-top-bottom, but acting on the other window.
  

• New user option delete-window-choose-selected.
  

  This allows specifying how Emacs chooses which window will be the
  frame's selected window after the currently selected window is
  deleted.
  

• New argument NO-OTHER for some window functions.
  

  get-lru-window, get-mru-window and get-largest-window now accept a
  new optional argument NO-OTHER which, if non-nil, avoids returning a
  window whose no-other-window parameter is non-nil.
  

• New display-buffer function display-buffer-use-least-recent-window.
  

  This is like display-buffer-use-some-window, but won't reuse the
  current window, and when called repeatedly will try not to reuse a
  previously selected window.
  

• New function window-bump-use-time.
  

  This updates the use time of a window.
  

2.3.30. Minibuffer

• Minibuffer scrolling is now conservative by default.
  

  This is controlled by the new variable scroll-minibuffer-conservatively.
  It is t by default; setting it to nil will cause scrolling in the
  minibuffer obey the value of scroll-conservatively.
  

• Improved handling of minibuffers on switching frames.
  

  By default, when you switch to another frame, an active minibuffer now
  moves to the newly selected frame. Nevertheless, the effect of what
  you type in the minibuffer happens in the frame where the minibuffer
  was first activated. An alternative behavior is available by
  customizing minibuffer-follows-selected-frame to nil. Here, the
  minibuffer stays in the frame where you first opened it, and you must
  switch back to this frame to continue or abort its command. The old
  behavior, which mixed these two, can be approximated by customizing
  minibuffer-follows-selected-frame to a value which is neither nil
  nor t.
  

• New user option read-minibuffer-restore-windows.
  

  When customized to nil, it uses minibuffer-restore-windows in
  minibuffer-exit-hook to remove only the window showing the
  *Completions* buffer, but keeps all other windows created
  while the minibuffer was active.
  

• New variable redisplay-adhoc-scroll-in-resize-mini-windows.
  

  Customizing it to nil will disable the ad-hoc auto-scrolling of
  minibuffer text shown in mini-windows when resizing those windows.
  The default heuristics of that scrolling can be counter productive in
  some corner cases, though the cure might be worse than the disease.
  This said, the effect should be negligible in the vast majority of
  cases anyway.
  

2.3.31. Mode Line

• New user option mode-line-compact.
  

  If non-nil, repeating spaces are compressed into a single space. If
  long, this is only done when the mode line is longer than the
  current window width (in columns).
  

• New user options to control format of line/column numbers in the mode line.
  

  mode-line-position-line-format is the line number format (when
  line-number-mode is on), mode-line-position-column-format is
  the column number format (when column-number-mode is on), and
  mode-line-position-column-line-format is the combined format (when
  both modes are on).
  

2.3.32. Tab Bars and Tab Lines

• The prefix key C-x t t can be used to display a buffer in a new tab.
  

  Typing C-x t t before a command will cause the buffer shown by that
  command to be displayed in a new tab. C-x t t is bound to the
  command other-tab-prefix.
  

• New command C-x t C-r to open file read-only in the other tab.
  
• The tab bar now supports more mouse commands.
  

  Clicking mouse-2 closes the tab, mouse-3 displays the context menu
  with items that operate on the clicked tab. Dragging the tab with
  mouse-1 moves it to another position on the tab bar. Mouse wheel
  scrolling switches to the previous/next tab, and holding the Shift key
  during scrolling moves the tab to the left/right.
  

• Frame-specific appearance of the tab bar when tab-bar-show is a number.
  

  When tab-bar-show is a number, the tab bar on different frames can
  be shown or hidden independently, as determined by the number of tabs
  on each frame compared to the numerical value of tab-bar-show.
  

• New command toggle-frame-tab-bar.
  

  It can be used to enable/disable the tab bar on the currently selected
  frame regardless of the values of tab-bar-mode and tab-bar-show.
  This allows enabling/disabling the tab bar independently on different
  frames.
  

• New user option tab-bar-format defines a list of tab bar items.
  

  When it contains tab-bar-format-global (possibly appended after
  tab-bar-format-align-right), then after enabling display-time-mode
  (or any other mode that uses global-mode-string) it displays time
  aligned to the right on the tab bar instead of on the mode line.
  When tab-bar-format-tabs is replaced with tab-bar-format-tabs-groups,
  the tab bar displays tab groups.
  

• New optional key binding for tab-last.
  

  If you customize the user option tab-bar-select-tab-modifiers to
  allow selecting tabs using their index numbers, the <MODIFIER>-9 key
  is bound to tab-last, and switches to the last tab. Here <MODIFIER>
  is any of the modifiers in the list that is the value of
  tab-bar-select-tab-modifiers. You can also use positive indices,
  which count from the last tab: 1 is the last tab, 2 the one before
  that, etc.
  

• New command tab-duplicate bound to C-x t n.
  
• C-x t N creates a new tab at the specified absolute position.
  

  The position is provided as prefix arg, and specifies an index that
  starts at 1. Negative values count from the end of the tab bar.
  

• C-x t M moves the current tab to the specified absolute position.
  

  The position is provided as prefix arg, whose interpretation is as in
  C-x t N.
  

• C-x t G assigns a tab to a named group of tabs.
  

  tab-close-group closes all tabs that belong to the selected group.
  The user option tab-bar-new-tab-group defines the default group of
  new tabs. After customizing tab-bar-tab-post-change-group-functions
  to tab-bar-move-tab-to-group, changing the group of a tab will also
  move it closer to other tabs in the same group.
  

• New user option tab-bar-tab-name-format-function.
  
• New user option tab-line-tab-name-format-function.
  
• The tabs in the tab line can now be scrolled using horizontal scroll.
  

  If your mouse or trackpad supports it, you can now scroll tabs when
  the mouse pointer is in the tab line by scrolling left or right.
  

• New tab-line faces and user options.
  

  The face tab-line-tab-special is used for tabs whose buffers are
  special, i.e. buffers that don't visit a file. The face
  tab-line-tab-modified is used to display modified, file-backed
  buffers. The face tab-line-tab-inactive-alternate is used to
  display inactive tabs with an alternating background color, making
  them easier to distinguish, especially if the face tab-line-tab is
  configured to not display with a box; this alternate face is only
  applied when the user option tab-line-tab-face-functions is so
  configured. That option may also be used to customize tab-line faces
  in other ways.
  

2.3.33. Mouse wheel

• Mouse wheel scrolling now defaults to one line at a time.
  
• Mouse wheel scrolling now works on more parts of frame's display.
  

  When using mouse-wheel-mode, the mouse wheel will now scroll also when
  the mouse cursor is on the scroll bars, fringes, margins, header line,
  and mode line. (mouse-wheel-mode is enabled by default on most graphical
  displays.)
  

• Mouse wheel scrolling with Shift modifier now scrolls horizontally.
  

  This works in text buffers and over images. Typing a numeric prefix arg
  (e.g. M-5) before starting horizontal scrolling changes its step value.
  The value is saved in the user option mouse-wheel-scroll-amount-horizontal.
  

2.3.34. Customize

• Customize buffers can now be reverted with C-x x g.
  
• Most customize commands now hide obsolete user options.
  

  Obsolete user options are no longer shown in the listings produced by
  the commands customize, customize-group, customize-apropos and
  customize-changed.
  

  To customize obsolete user options, use customize-option or
  customize-saved.
  

• New SVG icons for checkboxes and arrows.
  

  They will be used automatically instead of the old icons. If Emacs is
  built without SVG support, the old icons will be used instead.
  

2.3.35. Help

• The order of things displayed in the *Help* buffer has been changed.
  

  The indented "administrative" block (containing the "probably
  introduced" and "other relevant functions" (and similar things) has
  been moved to after the doc string.
  

• New command describe-command shows help for a command.
  

  This can be used instead of describe-function for interactive
  commands and is globally bound to C-h x.
  

• New command describe-keymap describes keybindings in a keymap.
  
• New command apropos-function.
  

  This works like C-u M-x apropos-command but is more discoverable.
  

• New keybinding C-h R prompts for an Info manual and displays it.
  
• Keybindings in help-mode use the new help-key-binding face.
  

  This face is added by substitute-command-keys to any "\[command]"
  substitution. The return value of that function should consequently
  be assumed to be a propertized string. To prevent the function from
  adding the help-key-binding face, call substitute-command-keys
  with the new optional argument NO-FACE non-nil.
  

  Note that the new face will also be used in tooltips. When using the
  GTK toolkit, this is only true if x-gtk-use-system-tooltips is t.
  

• New user option help-enable-symbol-autoload.
  

  If non-nil, displaying help for an autoloaded function whose
  autoload form provides no documentation string will try to load the
  file it's from. This will give more extensive help for such
  functions.
  

• The help-for-help (C-h C-h) screen has been redesigned.
  
• New convenience commands with short keys in the *Help* buffer.
  

  New command help-view-source (s) will view the source file (if
  any) of the current help topic. New command help-goto-info (i)
  will look up the current symbol (if any) in Info. New command
  help-customize (c) will customize the user option or the face
  (if any) whose doc string is being shown in the *Help* buffer.
  

• New user option describe-bindings-outline.
  

  It enables outlines in the output buffer of describe-bindings that
  can provide a better overview in a long list of available bindings.
  

• New commands to describe buttons and widgets.
  

  widget-describe (on a widget) will pop up the *Help* buffer and
  give a description of the properties. Likewise button-describe does
  the same for a button.
  

• Improved "find definition" feature of *Help* buffers.
  

  Now clicking on the link to find the definition of functions generated
  by cl-defstruct, or variables generated by define-derived-mode,
  for example, will go to the exact place where they are defined.
  

• New commands apropos-next-symbol and apropos-previous-symbol.
  

  These new navigation commands are bound to n and p in
  apropos-mode.
  

• The command view-lossage can now be invoked from the menu bar.
  

  The menu bar "Help" menu now has a "Show Recent Inputs" item under the
  "Describe" sub-menu.
  

• New command lossage-size.
  

  It allows users to change the maximum number of keystrokes and
  commands recorded for the purpose of view-lossage.
  

• Closing the *Help* buffer from the toolbar now buries the buffer.
  

  In previous Emacs versions, the *Help* buffer was killed instead when
  clicking the "X" icon in the tool bar.
  

• g (revert-buffer) in help-mode no longer requires confirmation.
  

2.3.36. File Locks

• New user option lock-file-name-transforms.
  

  This option allows controlling where lock files are written. It uses
  the same syntax as auto-save-file-name-transforms.
  

• New user option remote-file-name-inhibit-locks.
  

  When non-nil, this option suppresses lock files for remote files.
  Default is nil.
  

• New minor mode lock-file-mode.
  

  This command, called interactively, toggles the local value of
  create-lockfiles in the current buffer.
  

2.3.37. Emacs Server

• New user option server-client-instructions.
  

  When emacsclient connects, Emacs will (by default) output a message
  about how to exit the client frame. If server-client-instructions
  is set to nil, this message is inhibited.
  

• New command server-edit-abort.
  

  This command (not bound to any key by default) can be used to abort
  an edit instead of marking it as "Done" (which the C-x # command
  does). The emacsclient program exits with an abnormal status as
  result of this command.
  

• New desktop integration for connecting to the server.
  

  If your operating system's desktop environment is
  freedesktop.org-compatible (which is true of most GNU/Linux and other
  recent Unix-like desktops), you may use the new "Emacs (Client)"
  desktop menu entry to open files in an existing Emacs instance rather
  than starting a new one. The daemon starts if it is not already
  running.
  

2.3.38. Miscellaneous

• New command font-lock-update, bound to C-x x f.
  

  This command updates the syntax highlighting in this buffer.
  

• New command memory-report.
  

  This command opens a new buffer called *Memory Report* and gives a
  summary of where Emacs is using memory currently.
  

• New command submit-emacs-patch.
  

  This works like report-emacs-bug, but is more geared towards sending
  patches to the Emacs issue tracker.
  

• New face apropos-button.
  

  Applies to buttons that indicate a face.
  

• New face font-lock-doc-markup-face.
  

  Intended for documentation mark-up syntax and tags inside text that
  uses font-lock-doc-face, which it should appropriately stand out
  against and harmonize with. It would typically be used in structured
  documentation comments in program source code by language-specific
  modes, for mark-up conventions like Haddock, Javadoc or Doxygen. By
  default this face inherits from font-lock-constant-face.
  

• New face box style flat-button.
  

  This is a plain 2D button, but uses the background color instead of
  the foreground color.
  

• New faces shortdoc-heading and shortdoc-section.
  

  Applied to shortdoc headings and sections.
  

• New face separator-line.
  

  This is used by make-separator-line (see below).
  

• redisplay-skip-fontification-on-input helps Emacs keep up with fast input.
  

  This is another attempt to solve the problem of handling high key repeat rate
  and other "slow scrolling" situations. It is hoped it behaves better
  than fast-but-imprecise-scrolling and jit-lock-defer-time.
  It is not enabled by default.
  

• Obsolete aliases are no longer hidden from command completion.
  

  Completion of command names now considers obsolete aliases as
  candidates, if they were marked obsolete in the current major version
  of Emacs. Invoking a command via an obsolete alias now mentions the
  obsolescence fact and shows the new name of the command.
  

• Support for (box . SIZE) 'cursor-type'.
  

  By default, box cursor always has a filled box shape. But if you
  specify cursor-type to be (box . SIZE), the cursor becomes a hollow
  box if the point is on an image larger than SIZE pixels in any
  dimension.
  

• The user can now customize how "default" values are prompted for.
  

  The new utility function format-prompt has been added which uses the
  new minibuffer-default-prompt-format user option to format "default"
  prompts. This means that prompts that look like "Enter a number
  (default 10)" can be customized to look like, for instance, "Enter a
  number [10]", or not have the default displayed at all, like "Enter a
  number". (This only affects callers that were altered to use
  format-prompt.)
  

• New help window when Emacs prompts before opening a large file.
  

  Commands like find-file or visit-tags-table ask to visit a file
  normally or literally when the file is larger than a certain size (by
  default, 9.5 MiB). Press ? or C-h in that prompt to read more
  about the different options to visit a file, how you can disable the
  prompt, and how you can tweak the file size threshold.
  

• Emacs now defaults to UTF-8 instead of ISO-8859-1.
  

  This is only for the default, where the user has set no LANG (or
  similar) variable or environment. This change should lead to no
  user-visible changes for normal usage.
  

• global-display-fill-column-indicator-mode skips some buffers.
  

  By default, turning on global-display-fill-column-indicator-mode
  doesn't turn on display-fill-column-indicator-mode in special-mode
  buffers. This can be controlled by customizing the user option
  global-display-fill-column-indicator-modes.
  

• nobreak-char-display now also affects all non-ASCII space characters.
  

  Previously, this was limited only to NO-BREAK SPACE and hyphen
  characters. Now it also covers the rest of the non-ASCII Unicode
  space characters. Also, unlike in previous versions of Emacs, the
  non-ASCII characters are displayed as themselves when
  nobreak-char-display is t, i.e. they are not replaced on display
  with the ASCII space and hyphen characters.
  

• New backward compatibility variable nobreak-char-ascii-display.
  

  This variable is nil by default, and non-ASCII space and hyphen
  characters are displayed as themselves, even if nobreak-char-display
  is non-nil. If nobreak-char-ascii-display is set to a non-nil
  value, the non-ASCII space and hyphen characters are instead displayed
  as their ASCII counterparts: spaces and ASCII hyphen (a.k.a. "dash")
  characters. This provides backward compatibility feature for the
  change described above, where the non-ASCII characters are no longer
  replaced with their ASCII counterparts when nobreak-char-display is
  t. You may need this on text-mode terminals that produce messed up
  display when non-ASCII spaces and hyphens are written to the display.
  (This variable is only effective when nobreak-char-display is t.)
  

• Improved support for terminal emulators that encode the Meta flag.
  

  Some terminal emulators set the 8th bit of Meta characters, and then
  encode the resulting character code as if it were non-ASCII character
  above codepoint 127. Previously, the only way of using these in Emacs
  was to set up the terminal emulator to use the ESC characters to send
  Meta characters to Emacs, e.g., send "ESC x" when the user types
  M-x. You can now avoid the need for this setup of such terminal
  emulators by using the new input-meta-mode with the special value
  encoded with these terminal emulators.
  

• auto-composition-mode can now be selectively disabled on some TTYs.
  

  Some text-mode terminals produce display glitches trying to compose
  characters. The auto-composition-mode can now have a string value
  that names a terminal type; if the value returned by the tty-type
  function compares equal with that string, automatic composition will
  be disabled in windows shown on that terminal. The Linux terminal
  sets this up by default.
  

• Support for the strike-through face attribute on TTY frames.
  

  If your terminal's termcap or terminfo database entry has the smxx
  capability defined, Emacs will now emit the prescribed escape
  sequences necessary to render faces with the strike-through
  attribute on TTY frames.
  

• TTY menu navigation is now supported in xterm-mouse-mode.
  

  TTY menus support mouse navigation and selection when xterm-mouse-mode
  is active. When run on a terminal, clicking on the menu bar with the
  mouse now pops up a TTY menu by default instead of running the command
  tmm-menubar. To restore the old behavior, set the user option
  tty-menu-open-use-tmm to non-nil.
  

• M-x report-emacs-bug will no longer include "Recent messages" section.
  

  These were taken from the *Messages* buffer, and may inadvertently
  leak information from the reporting user.
  

• C-u M-x dig will now prompt for a query type to use.
  
• Rudimentary support for the st terminal emulator.
  

  Emacs now supports 256 color display on the st terminal emulator.
  

• Update IRC-related references to point to Libera.Chat.
  

  The Free Software Foundation and the GNU Project have moved their
  official IRC channels from the Freenode network to Libera.Chat. For the
  original announcement and the follow-up update, including more details,
  see:
  

  https://lists.gnu.org/archive/html/info-gnu/2021-06/msg00005.html
  https://lists.gnu.org/archive/html/info-gnu/2021-06/msg00007.html
  

  Given the relocation of GNU and FSF's official IRC channels, as well
  as #emacs and various other Emacs-themed channels (see the link below)
  to Libera.Chat, IRC-related references in the Emacs repository have
  now been updated to point to Libera.Chat.
  

  https://lists.gnu.org/archive/html/info-gnu-emacs/2021-06/msg00000.html
  

2.4.1. toggle-truncate-lines now disables visual-line-mode.

2.4.2. electric-indent-mode now also indents inside strings and comments.

(add-hook 'electric-indent-functions
          (lambda (_) (if (nth 8 (syntax-ppss)) 'no-indent)))

2.4.3. The M-o (facemenu-keymap) global binding has been removed.

(require 'facemenu)
(define-key global-map "\M-o" 'facemenu-keymap)
(define-key facemenu-keymap "\es" 'center-line)
(define-key facemenu-keymap "\eS" 'center-paragraph)

2.4.4. The M-o M-s and M-o M-S global bindings have been removed.

(define-key global-map "\M-o\M-s" 'center-line)
(define-key global-map "\M-o\M-S" 'center-paragraph)

2.4.5. The M-o M-o global binding has been removed.

2.4.6. The escape sequence \e[29~ in Xterm is now mapped to menu.

2.4.7. New user option xterm-store-paste-on-kill-ring.

2.4.8. vc-print-branch-log shows the change log from its root directory.

2.4.9. project-shell and shell now use pop-to-buffer-same-window.

2.4.10. In nroff-mode, center-line is no longer bound to a key.

2.4.11. In f90-mode, the backslash character (\) no longer escapes.

(modify-syntax-entry ?\\ "\\" f90-mode-syntax-table)

2.4.12. Setting fill-column to nil is obsolete.

(add-hook 'foo-mode-hook (lambda () (auto-fill-mode -1))

2.5.1. Input methods

• Emacs now supports "transient" input methods.
  

  A transient input method is enabled for inserting a single character,
  and is then automatically disabled. C-x \ temporarily enables the
  selected transient input method. Use C-u C-x \ to select a
  transient input method (which can be different from the input method
  enabled by C-\). For example, C-u C-x \ compose RET selects the
  compose input method; then typing C-x \ 1 2 will insert the
  character ½, and disable the compose input method afterwards.
  You can use C-x \ in incremental search to insert a single character
  to the search string.
  

• New input method compose based on X Multi_key sequences.
  
• New input method iso-transl with the same keys as C-x 8.
  

  After selecting it as a transient input method with 'C-u C-x \
  iso-transl RET', it supports the same key sequences as C-x 8,
  so e.g. like C-x 8 [ inserts a left single quotation mark,
  C-x \ [ does the same.
  

• New user option read-char-by-name-sort.
  

  It defines the sorting order of characters for completion of C-x 8 RET TAB
  and can be customized to sort them by codepoints instead of character names.
  Additionally, you can group characters by Unicode blocks after customizing
  completions-group and completions-group-sort.
  

• Improved language transliteration in Malayalam input methods.
  

  Added a new Mozhi scheme. The inapplicable ITRANS scheme is now
  deprecated. Errors in the Inscript method were corrected.
  

• New input method cham.
  

  There's also a Cham greeting in "etc/HELLO".
  

• New input methods for Lakota language orthographies.
  

  Two orthographies are represented here, the Suggested Lakota
  Orthography and what is known as the White Hat Orthography. Input
  methods lakota-slo-prefix, lakota-slo-postfix, and
  lakota-white-hat-postfix have been added. There is also a Lakota
  greeting in "etc/HELLO".
  

2.5.2. Standalone M-y allows interactive selection from previous kills.

2.5.3. New user option word-wrap-by-category.

2.5.4. New command undo-redo.

2.5.5. New commands copy-matching-lines and kill-matching-lines.

2.5.6. New user option kill-transform-function.

2.5.7. save-interprogram-paste-before-kill can now be a number.

2.5.8. New user option tab-first-completion.

2.5.9. indent-tabs-mode is now a global minor mode instead of just a variable.

2.5.10. New choice permanent for shift-select-mode.

2.5.11. The "Edit => Clear" menu item now obeys a rectangular region.

2.5.12. New command revert-buffer-with-fine-grain.

2.5.13. New command revert-buffer-quick.

2.5.14. New user option revert-buffer-quick-short-answers.

2.5.15. New user option query-about-changed-file.

2.5.16. New value save-some-buffers-root of save-some-buffers-default-predicate.

2.5.17. New user option save-place-abbreviate-file-names.

2.5.18. New user options copy-region-blink-delay and delete-pair-blink-delay.

2.5.19. zap-up-to-char now uses read-char-from-minibuffer.

2.5.20. Input history for goto-line can now be made local to every buffer.

2.5.21. New command goto-line-relative for use in a narrowed buffer.

2.5.22. goto-char prompts for the character position.

2.5.23. Auto-saving via auto-save-visited-mode can now be inhibited.

2.5.24. New command kdb-macro-redisplay to force redisplay in keyboard macros.

2.5.25. blink-cursor-mode is now enabled by default regardless of the UI.

2.5.26. show-paren-mode is now enabled by default.

2.5.27. New minor mode show-paren-local-mode.

(add-hook 'prog-mode-hook #'show-paren-local-mode)

2.6.1. Isearch and Replace

• Interactive regular expression search now uses faces for sub-groups.
  

  E.g., C-M-s foo-\([0-9]+\) will now use the isearch-group-1 face
  on the part of the regexp that matches the sub-expression "[0-9]+".
  By default, there are two faces for sub-group highlighting, but you
  can define more faces whose names are of the form isearch-group-N,
  where N are successive numbers above 2.
  

  This is controlled by the search-highlight-submatches user option.
  This feature is available only on terminals that have enough colors to
  distinguish between sub-expression highlighting.
  

• Interactive regular expression replace now uses faces for sub-groups.
  

  Like search-highlight-submatches, this is controlled by the new user option
  query-replace-highlight-submatches.
  

• New key M-s M-. starts isearch looking for the thing at point.
  

  This key is bound to the new command isearch-forward-thing-at-point.
  The new user option isearch-forward-thing-at-point defines
  a list of symbols to try to get the "thing" at point. By default,
  the first element of the list is region that tries to yank
  the currently active region to the search string.
  

• New user option isearch-wrap-pause defines how to wrap the search.
  

  There are choices to disable wrapping completely and to wrap immediately.
  When wrapping immediately, it consistently handles the numeric arguments
  of C-s (isearch-repeat-forward) and C-r (isearch-repeat-backward),
  continuing with the remaining count after wrapping.
  

• New user option isearch-repeat-on-direction-change.
  

  When this option is set, direction changes in Isearch move to another
  search match, if there is one, instead of moving point to the other
  end of the current match.
  

• New user option isearch-allow-motion.
  

  When isearch-allow-motion is set, the commands beginning-of-buffer,
  end-of-buffer, scroll-up-command and scroll-down-command, when
  invoked during Isearch, move respectively to the first occurrence of
  the current search string in the buffer, the last one, the first one
  after the current window, and the last one before the current window.
  Additionally, users can change the meaning of other motion commands
  during Isearch by using their isearch-motion property. The user
  option isearch-motion-changes-direction controls whether the
  direction of the search changes after a motion command.
  

• New user option lazy-highlight-no-delay-length.
  

  Lazy highlighting of matches in Isearch now starts immediately if the
  search string is at least this long. lazy-highlight-initial-delay
  still applies for shorter search strings, which avoids flicker in the
  search buffer due to too many matches being highlighted.
  

• The default search-whitespace-regexp value has changed.
  

  This used to be "\-+", which meant that it was mode-dependent whether
  newlines were included in the whitespace set. This has now been
  changed to only match spaces and tab characters.
  

2.6.2. Dired

• New user option dired-kill-when-opening-new-dired-buffer.
  

  If non-nil, Dired will kill the current buffer when selecting a new
  directory to display.
  

• Behavior change on dired-do-chmod.
  

  As a security precaution, Dired's M command no longer follows
  symbolic links. Instead, it changes the symbolic link's own mode;
  this always fails on platforms where such modes are immutable.
  

• Behavior change on dired-clean-confirm-killing-deleted-buffers.
  

  Previously, if dired-clean-up-buffers-too was non-nil, and
  dired-clean-confirm-killing-deleted-buffers was nil, the buffers
  wouldn't be killed. This combination will now kill the buffers.
  

• New user option dired-switches-in-mode-line.
  

  This user option controls how ls switches are displayed in the mode
  line, and allows truncating them (to preserve space on the mode line)
  or showing them literally, either instead of, or in addition to,
  displaying "by name" or "by date" sort order.
  

• New user option dired-compress-directory-default-suffix.
  

  This user option controls the default suffix for compressing a
  directory. If it's nil, ".tar.gz" will be used. Refer to
  dired-compress-files-alist for a list of supported suffixes.
  

• New user option dired-compress-file-default-suffix.
  

  This user option controls the default suffix for compressing files.
  If it's nil, ".gz" will be used. Refer to dired-compress-file-alist
  for a list of supported suffixes.
  

• Broken and circular links are shown with the dired-broken-symlink face.
  
• = (dired-diff) will now put all backup files into the M-n history.
  

  When using = on a file with backup files, the default file to use
  for diffing is the newest backup file. You can now use M-n to quickly
  select a different backup file instead.
  

• New user option dired-maybe-use-globstar.
  

  If set, enables globstar (recursive globbing) in shells that support
  this feature, but have it turned off by default. This allows producing
  directory listings with files matching a wildcard in all the
  subdirectories of a given directory. The new variable
  dired-enable-globstar-in-shell lists which shells can have globstar
  enabled, and how to enable it.
  

• New user option dired-copy-dereference.
  

  If set to non-nil, Dired will dereference symbolic links when copying.
  This can be switched off on a per-usage basis by providing
  dired-do-copy with a C-u prefix.
  

• New user option dired-do-revert-buffer.
  

  Non-nil reverts the destination Dired buffer after performing one
  of these operations: dired-do-copy, dired-do-rename,
  dired-do-symlink, dired-do-hardlink.
  

• New user option dired-mark-region.
  

  This option affects all Dired commands that mark files. When non-nil
  and the region is active in Transient Mark mode, then Dired commands
  operate only on files in the active region. The values file and
  line of this user option define the details of marking the file at
  the end of the region.
  

• State changing VC operations are supported in Dired.
  

  These operations are supported on files and directories via the new
  command dired-vc-next-action.
  

• dired-jump and dired-jump-other-window moved from dired-x to dired.
  

  The dired-jump and dired-jump-other-window commands have been
  moved from the dired-x package to dired. The user option
  dired-bind-jump no longer has any effect and is now obsolete.
  The commands are now bound to C-x C-j and C-x 4 C-j by default.
  

  To get the old behavior of dired-bind-jump back and unbind the above
  keys, add the following to your init file:
  

  (global-set-key "\C-x\C-j" nil)
  (global-set-key "\C-x4\C-j" nil)
  

• dired-query now uses read-char-from-minibuffer.
  

  Using it instead of read-char-choice allows using C-x o
  to switch to the help window displayed after typing C-h.
  

2.6.3. Emacs 28.1 comes with Org v9.5.

2.6.4. Outline

• New commands to cycle heading visibility.
  

  Typing TAB on a heading line cycles the current section between
  "hide all", "subheadings", and "show all" states. Typing S-TAB
  anywhere in the buffer cycles the whole buffer between "only top-level
  headings", "all headings and subheadings", and "show all" states.
  

• New user option outline-minor-mode-cycle.
  

  This user option customizes outline-minor-mode, with the difference
  that TAB and S-TAB on heading lines cycle heading visibility.
  Typing TAB on a heading line cycles the current section between
  "hide all", "subheadings", and "show all" states. Typing S-TAB on a
  heading line cycles the whole buffer between "only top-level
  headings", "all headings and subheadings", and "show all" states.
  

• New user option outline-minor-mode-highlight.
  

  This user option customizes outline-minor-mode. It puts
  highlighting on heading lines using standard outline faces. This
  works well only when there are no conflicts with faces used by the
  major mode.
  

2.6.5. Ispell

• ispell-comments-and-strings now accepts START and END arguments.
  

  These arguments default to the active region when used interactively.
  

• New command ispell-comment-or-string-at-point.
  
• New user option ispell-help-timeout.
  

  This controls how long the ispell help (on the ? key) is displayed.
  

2.6.6. Flyspell mode

• Corrections and actions menu can be optionally bound to mouse-3.
  

  When Flyspell mode highlights a word as misspelled, you can click on
  it to display a menu of possible corrections and actions. You can now
  easily bind this menu to down-mouse-3 (usually the right mouse button)
  instead of mouse-2 (the default) by enabling context-menu-mode.
  

• The current dictionary is now displayed in the minor mode lighter.
  

  Clicking the dictionary name changes the current dictionary.
  

2.6.7. Package

• The new NonGNU ELPA archive is enabled by default alongside GNU ELPA.
  

  Thus, packages on NonGNU ELPA will appear by default in the list shown
  by list-packages.
  

• / s (package-menu-filter-by-status) changed parameter handling.
  

  The command was documented to take a comma-separated list of statuses
  to filter by, but instead it used the parameter as a regexp. The
  command has been changed so that it now works as documented, and
  checks statuses not as a regexp, but instead an exact match from the
  comma-separated list.
  

• New command package-browse-url and keystroke w.
  
• New commands to filter the package list.
  

  The filter commands are bound to the following keys:
  

  key binding
  — --–—
  / a package-menu-filter-by-archive
  / d package-menu-filter-by-description
  / k package-menu-filter-by-keyword
  / N package-menu-filter-by-name-or-description
  / n package-menu-filter-by-name
  / s package-menu-filter-by-status
  / v package-menu-filter-by-version
  / m package-menu-filter-marked
  / u package-menu-filter-upgradable
  / / package-menu-clear-filter
  

• Option to automatically native-compile packages upon installation.
  

  Customize the user option package-native-compile to enable automatic
  native compilation of packages when they are installed. That option
  is nil by default; if set non-nil, and if your Emacs was built with
  native-compilation support, each package will be natively compiled
  when it is installed, by invoking an asynchronous Emacs subprocess to
  run the native-compilation of the package files. (Be sure to leave
  Emacs running until these asynchronous subprocesses exit, or else the
  native-compilation will be aborted when you exit Emacs.)
  

• Column widths in list-packages display can now be customized.
  

  See the new user options package-name-column-width,
  package-version-column-width, package-status-column-width, and
  package-archive-column-width.
  

2.6.8. Info

• New user option Info-warn-on-index-alternatives-wrap.
  

  This option affects what happens when using the , command after
  looking up an entry with i in info buffers. If non-nil (the
  default), the , command will now display a warning when proceeding
  beyond the final index match, and tapping , once more will then take
  you to the first match.
  

2.6.9. Abbrev mode

• Emacs can now suggest to use an abbrev based on text you type.
  

  A new user option, abbrev-suggest, enables the new abbrev suggestion
  feature. When enabled, if a user manually types a piece of text that
  could have saved enough typing by using an abbrev, a hint will be
  displayed in the echo area, mentioning the abbrev that could have been
  used instead.
  

2.6.10. Bookmarks

• Bookmarks can now be targets for new tabs.
  

  When the bookmark.el library is loaded, a customize choice is added
  to tab-bar-new-tab-choice for new tabs to show the bookmark list.
  

• New user option bookmark-set-fringe-mark.
  

  If non-nil, setting a bookmark will set a fringe mark on the current
  line, and jumping to a bookmark will also set this mark.
  

• New user option bookmark-menu-confirm-deletion.
  

  In Bookmark Menu mode, Emacs by default does not prompt for
  confirmation when you type x to execute the deletion of bookmarks
  that have been marked for deletion. However, if this new option is
  non-nil then Emacs will require confirmation with yes-or-no-p before
  deleting.
  

• The list-bookmarks menu is now based on tabulated-list-mode.
  

  The interactive bookmark list will now benefit from features in
  tabulated-list-mode like sorting columns or changing column width.
  

  Support for the optional "inline" header line, allowing for a
  header without using header-line-format, has been dropped.
  The variables bookmark-bmenu-use-header-line and
  bookmark-bmenu-inline-header-height are now obsolete.
  

2.6.11. Recentf

• The recentf files are no longer backed up.
  
• recentf-auto-cleanup now repeats daily when set to a time string.
  

  When recentf-auto-cleanup is set to a time string, it now repeats
  every day, rather than only running once after the mode is turned on.
  

2.6.12. Calc

• The behavior when doing forward-delete has been changed.
  

  Previously, using the C-d command would delete the final number in
  the input field, no matter where point was. This has been changed to
  work more traditionally, with C-d deleting the next character.
  Likewise, point isn't moved to the end of the string before inserting
  digits.
  

• Setting the word size to zero disables word clipping.
  

  The word size normally clips the results of certain bit-oriented
  operations such as shifts and bitwise XOR. A word size of zero, set
  by b w, makes the operation have effect on the whole argument values
  and the result is not truncated in any way.
  

• The / operator now has higher precedence in (La)TeX input mode.
  

  It no longer has lower precedence than + and -.
  

• New user option calc-make-windows-dedicated.
  

  When this user option is non-nil, Calc will mark its windows as
  dedicated.
  

2.6.13. Calendar

• New user option calendar-time-zone-style.
  

  If numeric, calendar functions (eg calendar-sunrise-sunset) that display
  time zones will use a form like "+0100" instead of "CET".
  

2.6.14. Imenu

• New user option imenu-max-index-time.
  

  If creating the imenu index takes longer than specified by this
  option (default 5 seconds), imenu indexing is stopped.
  

2.6.15. Ido

• Switching on ido-mode now also overrides ffap-file-finder.
  
• Killing virtual ido buffers interactively will make them go away.
  

  Previously, killing a virtual ido buffer with ido-kill-buffer didn't
  do anything. This has now been changed, and killing virtual buffers
  with that command will remove the buffer from recentf.
  

2.6.16. So Long

• New so-long-predicate function so-long-statistics-excessive-p.
  

  It efficiently detects the presence of a long line anywhere in the
  buffer using buffer-line-statistics (see above). This is now the
  default predicate (replacing so-long-detected-long-line-p).
  

• Default values so-long-threshold and so-long-max-lines increased.
  

  The values of these user options have been raised to 10000 bytes and 500
  lines respectively, to reduce the likelihood of false-positives when
  global-so-long-mode is enabled. The latter value is now only used
  by the old predicate, as the new predicate knows the longest line in
  the entire buffer.
  

• so-long-target-modes now includes fundamental-mode by default.
  

  This means that global-so-long-mode will also process files which were
  not recognized. (This only has an effect if set-auto-mode chooses
  fundamental-mode'; buffers which are simply in 'fundamental-mode by
  default are unaffected.)
  

• New user options to preserve modes and variables.
  

  The new options so-long-mode-preserved-minor-modes and
  so-long-mode-preserved-variables allow specified mode and variable
  states to be maintained if so-long-mode replaces the original major
  mode. By default, these new options support view-mode.
  

2.6.17. Grep

• New user option grep-match-regexp matches grep markers to highlight.
  

  Grep emits SGR ANSI escape sequences to color its output. The new
  user option grep-match-regexp holds the regular expression to match
  the appropriate markers in order to provide highlighting in the source
  buffer. The user option can be customized to accommodate other
  grep-like tools.
  

• The lgrep command now ignores directories.
  

  On systems where the grep command supports it, directories will be
  skipped.
  

• Commands that use grep-find now follow symlinks for command-line args.
  

  This is because the default value of grep-find-template now includes
  the find option -H. Commands that use that variable, including
  indirectly via a call to xref-matches-in-directory, might be
  affected. In particular, there should be no need anymore to ensure
  any directory names on the find command lines end in a slash.
  This change is for better compatibility with old versions of non-GNU
  find, such as the one used on macOS.
  

• New utility function grep-file-at-point.
  

  This returns the name of the file at point (if any) in grep-mode
  buffers.
  

2.6.18. Shell

• New command in shell-mode': 'shell-narrow-to-prompt.
  

  This is bound to C-x n d in shell-mode buffers, and narrows to the
  command line under point (and any following output).
  

• New user option shell-has-auto-cd.
  

  If non-nil, shell-mode handles implicit "cd" commands, changing the
  directory if the command is a directory. Useful for shells like "zsh"
  that has this feature.
  

2.6.19. Term mode

• New user option term-scroll-snap-to-bottom.
  

  By default, term and ansi-term will now recenter the buffer so
  that the prompt is on the final line in the window. Setting this new
  user option to nil inhibits this behavior.
  

• New user option term-set-terminal-size.
  

  If non-nil, the LINES and COLUMNS environment variables will be set
  based on the current window size. In previous versions of Emacs, this
  was always done (and that could lead to odd displays when resizing the
  window after starting). This variable defaults to nil.
  

• term-mode now supports "bright" color codes.
  

  "Bright" ANSI color codes are now displayed using the color values
  defined in term-color-bright-*. In addition, bold text with regular
  ANSI colors can be displayed as "bright" if ansi-color-bold-is-bright
  is non-nil.
  

2.6.20. Eshell

• eshell-hist-ignoredups can now also be used to mimic "erasedups" in bash.
  
• Environment variable INSIDE_EMACS is now copied to subprocesses.
  

  Its value contains the result of evaluating '(format "%s,eshell"
  emacs-version)'. Other package names, like "tramp", could also be included.
  

• Eshell no longer re-initializes its keymap every call.
  

  This allows users to use (define-key eshell-mode-map ...) as usual.
  Some modules have their own minor mode now to account for these
  changes.
  

• Support for bookmark.el.
  

  The command bookmark-set (bound to C-x r m) is now supported, and
  will create a bookmark that opens the current directory in Eshell.
  

2.6.21. Archive mode

• Archive mode can now parse ".squashfs" files.
  
• Can now modify members of ar archives.
  
• Display of summaries is unified between backends.
  
• New user option and command to control displayed columns.
  

  New user option archive-hidden-columns and new command
  archive-hideshow-column let you control which columns are displayed
  and which are kept hidden.
  

• New command bound to C': 'archive-copy-file.
  

  This command extracts the file at point and writes its data to a
  file.
  

2.6.22. Browse URL

• Added support for custom URL handlers.
  

  There is a new variable browse-url-default-handlers and a user
  option browse-url-handlers being alists with '(REGEXP-OR-PREDICATE
  . FUNCTION)' entries allowing to define different browsing FUNCTIONs
  depending on the URL to be browsed. The variable is for default
  handlers provided by Emacs itself or external packages, the user
  option is for the user (and allows for overriding the default
  handlers).
  

  Formerly, one could do the same by setting
  browse-url-browser-function to such an alist. This usage is still
  supported but deprecated.
  

• Categorization of browsing commands into internal vs. external.
  

  All standard browsing commands such as browse-url-firefox,
  browse-url-mail, or eww have been categorized into internal (URL
  is browsed in Emacs) or external (an external application is spawned
  with the URL). This is done by adding a browse-url-browser-kind
  symbol property to the browsing commands. With a new command
  browse-url-with-browser-kind, an URL can explicitly be browsed with
  either an internal or external browser.
  

• Support for browsing of remote files.
  

  If a remote file is specified, a local temporary copy of that file is
  passed to the browser.
  

• Support for the conkeror browser is now obsolete.
  
• Support for the Mosaic browser has been removed.
  

  This support has been obsolete since 25.1.
  

2.6.23. Completion list mode

• Improved navigation in the *Completions* buffer.
  

  New key bindings have been added to completion-list-mode': 'n and
  p now navigate completions, and M-g M-c switches to the
  minibuffer and back to the completion list buffer.
  

2.6.24. Profiler

2.6.25. Icomplete

• New user option icomplete-matches-format.
  

  This allows controlling the current/total number of matches for the
  prompt prefix.
  

• New minor modes icomplete-vertical-mode and fido-vertical-mode.
  

  These modes modify Icomplete (icomplete-mode) and Fido
  (fido-mode), to display completion candidates vertically instead of
  horizontally. In Icomplete, completions are rotated and selection
  kept at the top. In Fido, completions scroll like a typical dropdown
  widget. Both these new minor modes will turn on their non-vertical
  counterparts first, if they are not on already.
  

• Default value of icomplete-compute-delay has been changed to 0.15 s.
  
• Default value of icomplete-max-delay-chars has been changed to 2.
  
• Reduced blinking while completing the next completions set.
  

  Icomplete doesn't hide the hint with the previously computed
  completions anymore when compute delay is in effect, or the previous
  computation has been aborted by input. Instead it shows the previous
  completions until the new ones are ready.
  

• Change in meaning of icomplete-show-matches-on-no-input.
  

  Previously, choosing a different completion with commands like C-.
  and then hitting RET would choose the default completion. Doing this
  will now choose the completion under point instead. Also when this option
  is nil, completions are not shown when the minibuffer reads a file name
  with initial input as the default directory.
  

2.6.26. Windmove

• New user options to customize windmove keybindings.
  

  These options include windmove-default-keybindings,
  windmove-display-default-keybindings,
  windmove-delete-default-keybindings,
  windmove-swap-states-default-keybindings.
  Also new mode windmove-mode enables the customized keybindings.
  

2.6.27. Occur mode

• New bindings in occur-mode.
  

  The command next-error-no-select is now bound to n and
  previous-error-no-select is bound to p.
  

• New command recenter-current-error.
  

  It is bound to l in Occur or compilation buffers, and recenters the
  current displayed occurrence/error.
  

• Matches in target buffers are now highlighted as in compilation-mode.
  

  The method of highlighting is specified by the user options
  next-error-highlight and next-error-highlight-no-select.
  

• A fringe arrow in the *Occur* buffer indicates the selected match.
  
• Occur mode may use a different type for occur-target property values.
  

  The value was previously always a marker set to the start of the first
  match on the line but can now also be a list of (BEGIN . END) pairs
  of markers delimiting each match on the line.
  This is a fully compatible change to the internal occur-mode
  implementation, and code creating their own occur-mode buffers will
  work as before.
  

2.6.28. Emacs Lisp mode

• The mode-line now indicates whether we're using lexical or dynamic scoping.
  
• A space between an open paren and a symbol changes the indentation rule.
  

  The presence of a space between an open paren and a symbol now is
  taken as a statement by the programmer that this should be indented
  as a data list rather than as a piece of code.
  

2.6.29. Lisp mode

• New minor mode cl-font-lock-built-in-mode for lisp-mode.
  

  The mode provides refined highlighting of built-in functions, types,
  and variables.
  

• Lisp mode now uses common-lisp-indent-function.
  

  To revert to the previous behavior,
  (setq lisp-indent-function 'lisp-indent-function) from lisp-mode-hook.
  

2.6.30. Change Logs and VC

• vc-revert-show-diff now has a third possible value: kill.
  

  If this user option is kill, then the diff buffer will be killed
  after the vc-revert action instead of buried.
  

• More VC commands can be used from non-file buffers.
  

  The relevant commands are those that don't change the VC state.
  The non-file buffers which can use VC commands are those that have
  their default-directory under VC.
  

• New face log-view-commit-body.
  

  This is used when expanding commit messages from vc-print-root-log
  and similar commands.
  

• New faces for vc-dir buffers.
  

  Those are: vc-dir-header, vc-dir-header-value, vc-dir-directory,
  vc-dir-file, vc-dir-mark-indicator, vc-dir-status-warning,
  vc-dir-status-edited, vc-dir-status-up-to-date,
  vc-dir-status-ignored.
  

• The responsible VC backend is now the most specific one.
  

  vc-responsible-backend loops over the backends in
  vc-handled-backends to determine which backend is responsible for a
  specific (unregistered) file. Previously, the first matching backend
  was chosen, but now the one with the most specific path is chosen (in
  case there's a directory handled by one backend inside another).
  

• New command vc-dir-root uses the root directory without asking.
  
• New commands vc-dir-mark-registered-files (bound to * r) and
  

  vc-dir-mark-unregistered-files.
  

• Support for bookmark.el.
  

  Bookmark locations can refer to VC directory buffers.
  

• New user option vc-hg-create-bookmark.
  

  It controls whether a bookmark or branch will be created when you
  invoke C-u C-x v s (vc-create-tag).
  

• vc-hg now uses hg summary to populate extra vc-dir headers.
  
• New user option vc-git-revision-complete-only-branches.
  

  If non-nil, only branches and remotes are considered when doing
  completion over Git branch names. The default is nil, which causes
  tags to be considered as well.
  

• New user option vc-git-log-switches.
  

  String or list of strings specifying switches for Git log under VC.
  

• Command vc-switch-backend is now obsolete.
  

  If you are still using it with any regularity, please file a bug
  report with some details.
  

• New variable vc-git-use-literal-pathspecs.
  

  The Git backend's function now treat all file names "literally", where
  some of them previously could interpret file names (pathspecs) as
  globs when they contain appropriate characters. Functions can bind
  the aforementioned variable to nil locally to avoid this.
  

2.6.31. Gnus

• New user option gnus-topic-display-predicate.
  

  This can be used to inhibit the display of some topics completely.
  

• nnimap now supports the oauth2.el library.
  
• New Summary buffer sort options for extra headers.
  

  The extra header sort option (C-c C-s C-x) prompts for a header
  and fails if no sort function has been defined. Sorting by
  Newsgroups (C-c C-s C-u) has been pre-defined.
  

• The # command in the Group and Summary buffer now toggles,
  

  instead of sets, the process mark.
  

• New user option gnus-process-mark-toggle.
  

  If non-nil (the default), the # command in the Group and Summary
  buffers will toggle, instead of set, the process mark.
  

• New user option gnus-registry-register-all.
  

  If non-nil (the default), create registry entries for all messages.
  If nil, don't automatically create entries, they must be created
  manually.
  

• New user options to customize the summary line specs "%[" and "%]".
  

  Four new options introduced in customization group
  gnus-summary-format. These are gnus-sum-opening-bracket,
  gnus-sum-closing-bracket, gnus-sum-opening-bracket-adopted, and
  gnus-sum-closing-bracket-adopted. Their default values are "[", "]",
  "<", ">" respectively. These options control the appearance of "%["
  and "%]" specs in the summary line format. "%[" will normally display
  the value of gnus-sum-opening-bracket, but can also be
  gnus-sum-opening-bracket-adopted for the adopted articles. "%]" will
  normally display the value of gnus-sum-closing-bracket, but can also
  be gnus-sum-closing-bracket-adopted for the adopted articles.
  

• New user option gnus-paging-select-next.
  

  This controls what happens when using commands like SPC and DEL to
  page the current article. If non-nil (the default), go to the
  next/prev article, but if nil, do nothing at the end/start of the article.
  

• New gnus-search library.
  

  A new unified search syntax which can be used across multiple
  supported search engines. Set gnus-search-use-parsed-queries to
  non-nil to enable.
  

• New value for user option smiley-style.
  

  Smileys can now be rendered with emojis instead of small images when
  using the new emoji value in smiley-style.
  

• New user option gnus-agent-eagerly-store-articles.
  

  If non-nil (which is the default), the Gnus Agent will store all read
  articles in the Agent cache.
  

• New user option gnus-global-groups.
  

  Gnus handles private groups differently from public (i.e., NNTP-like)
  groups. Most importantly, Gnus doesn't download external images from
  mail-like groups. This can be overridden by putting group names in
  gnus-global-groups: Any group present in that list will be treated
  like a public group.
  

• New scoring types for the Date header.
  

  You can now score based on the relative age of an article with the new
  < and > date scoring types.
  

• User-defined scoring is now possible.
  

  The new type is score-fn. More information in the Gnus manual node
  "(gnus) Score File Format".
  

• New backend nnselect.
  

  The newly added nnselect backend allows creating groups from an
  arbitrary list of articles that may come from multiple groups and
  servers. These groups generally behave like any other group: they may
  be ephemeral or persistent, and allow article marking, moving,
  deletion, etc. nnselect groups may be created like any other group,
  but there are three convenience functions for the common case of
  obtaining the list of articles as a result of a search:
  gnus-group-make-search-group (G g) that will prompt for an nnir
  search query and create a persistent group for that search;
  gnus-group-read-ephemeral-search-group (G G) that will prompt for
  an nnir search query and create an ephemeral group for that search;
  and gnus-summary-make-group-from-search (C-c C-p) that will create
  a persistent group with the search parameters of a current ephemeral
  search group.
  

  As part of this addition, the user option nnir-summary-line-format
  has been removed; its functionality is now available directly in the
  gnus-summary-line-format specs %G and %g. The user option
  gnus-refer-thread-use-nnir has been renamed to
  gnus-refer-thread-use-search.
  

• New user option gnus-dbus-close-on-sleep.
  

  On systems with D-Bus support, it is now possible to register a signal
  to close all Gnus servers before the system sleeps.
  

• The key binding of gnus-summary-search-article-forward has changed.
  

  This command was previously on M-s and shadowed the global M-s
  search prefix. The command has now been moved to M-s M-s. (For
  consistency, the M-s M-r key binding has been added for the
  gnus-summary-search-article-backward command.)
  

• The value for "all" in the large-newsgroup-initial group parameter has changed.
  

  It was previously nil, which didn't work, because nil is
  indistinguishable from not being present. The new value for "all" is
  the symbol all.
  

• The name of dependent Gnus sessions has changed from "slave" to "child".
  

  The names of the commands gnus-slave, gnus-slave-no-server and
  gnus-slave-unplugged have changed to gnus-child,
  gnus-child-no-server and gnus-child-unplugged respectively.
  

• The W Q summary mode command now takes a numerical prefix to
  

  allow adjusting the fill width.
  

• New variable mm-inline-font-lock.
  

  This variable is supposed to be bound by callers to determine whether
  inline MIME parts (that support it) are supposed to be font-locked or
  not.
  

2.6.32. Message

• Respect message-forward-ignored-headers more.
  

  Previously, this user option would not be consulted if
  message-forward-show-mml was nil and forwarding as MIME.
  

• New user option message-forward-included-mime-headers.
  

  This is used when forwarding messages as MIME, but not using MML.
  

• Message now supports the OpenPGP header.
  

  To generate these headers, add the new function
  message-add-openpgp-header to message-send-hook. The header will
  be generated according to the new message-openpgp-header user
  option.
  

• A change to how "Mail-Copies-To: never" is handled.
  

  If a user has specified "Mail-Copies-To: never", and Message was asked
  to do a "wide reply", some other arbitrary recipient would end up in
  the resulting "To" header, while the remaining recipients would be put
  in the "Cc" header. This is somewhat misleading, as it looks like
  you're responding to a specific person in particular. This has been
  changed so that all the recipients are put in the "To" header in these
  instances.
  

• New command to start Emacs in Message mode to send an email.
  

  Emacs can be defined as a handler for the "x-scheme-handler/mailto"
  MIME type with the following command: "emacs -f message-mailto %u".
  An "emacs-mail.desktop" file has been included, suitable for
  installing in desktop directories like "/usr/share/applications" or
  "~/.local/share/applications".
  Clicking on a mailto: link in other applications will then open
  Emacs with headers filled out according to the link, e.g.
  "mailto:larsi@gnus.org?subject=This+is+a+test". If you prefer
  emacsclient, use "emacsclient -e '(message-mailto "%u")'"
  or "emacsclient-mail.desktop".
  

• Change to default value of message-draft-headers user option.
  

  The Date symbol has been removed from the default value, meaning that
  draft or delayed messages will get a date reflecting when the message
  was sent. To restore the original behavior of dating a message
  from when it is first saved or delayed, add the symbol Date back to
  this user option.
  

• New command to take screenshots.
  

  In Message mode buffers, the C-c C-p (message-insert-screenshot)
  command has been added. It depends on using an external program to
  take the actual screenshot, and defaults to "ImageMagick import".
  

2.6.33. Smtpmail

• smtpmail now supports using the oauth2.el library.
  
• New user option smtpmail-store-queue-variables.
  

  If non-nil, SMTP variables will be stored together with the queued
  messages, and will then be used when sending with command
  smtpmail-send-queued-mail.
  

• Allow direct selection of smtp authentication mechanism.
  

  A server entry retrieved by auth-source can request a desired smtp
  authentication mechanism by setting a value for the key smtp-auth.
  

2.6.34. ElDoc

• New user option eldoc-echo-area-display-truncation-message.
  

  If non-nil (the default), eldoc will display a message saying
  something like "(Documentation truncated. Use `M-x eldoc-doc-buffer'
  to see rest)" when a message has been truncated. If nil, truncated
  messages will be marked with just "…" at the end.
  

• New hook eldoc-documentation-functions.
  

  This hook is intended to be used for registering doc string functions.
  These functions don't need to produce the doc string right away, they
  may arrange for it to be produced asynchronously. The results of all
  doc string functions are accessible to the user through the user
  option eldoc-documentation-strategy.
  

• New hook eldoc-display-functions.
  

  This hook is intended to be used for displaying doc strings. The
  functions receive the doc string composed according to
  eldoc-documentation-strategy and are tasked with displaying it to
  the user. Examples of such functions would use the echo area, a
  separate buffer, or a tooltip.
  

• New user option eldoc-documentation-strategy.
  

  The built-in choices available for this user option let users compose
  the results of eldoc-documentation-functions in various ways, even
  if some of those functions are synchronous and some asynchronous.
  The user option replaces eldoc-documentation-function, which is now
  obsolete.
  

• eldoc-echo-area-use-multiline-p is now handled by ElDoc.
  

  The user option eldoc-echo-area-use-multiline-p is now handled
  by the ElDoc library itself. Functions in
  eldoc-documentation-functions don't need to worry about consulting
  it when producing a doc string.
  

2.6.35. Tramp

• New connection method "mtp".
  

  It allows accessing media devices like cell phones, tablets or
  cameras.
  

• New connection method "sshfs".
  

  It allows accessing remote files via a file system mounted with
  sshfs.
  

• Tramp supports SSH authentication via a hardware security key now.
  

  This requires at least OpenSSH 8.2, and a FIDO U2F compatible
  security key, like yubikey, solokey, or nitrokey.
  

• Trashed remote files are moved to the local trash directory.
  

  All remote files that are trashed are moved to the local trash
  directory, except remote encrypted files, which are always deleted.
  

• New command tramp-crypt-add-directory.
  

  This command marks a remote directory to contain only encrypted files.
  See the "(tramp) Keeping files encrypted" node of the Tramp manual for
  details. This feature is experimental.
  

• Support of direct asynchronous process invocation.
  

  When Tramp connection property "direct-async-process" is set to
  non-nil for a given connection, make-process and start-file-process
  calls are performed directly as in "ssh … <command>". This avoids
  initialization performance penalties. See the "(tramp) Improving
  performance of asynchronous remote processes" node of the Tramp manual
  for details, and also for a discussion or restrictions. This feature
  is experimental.
  

• New user option tramp-debug-to-file.
  

  When non-nil, this user option instructs Tramp to mirror the debug
  buffer to a file under the "/tmp/" directory. This is useful, if (in
  rare cases) Tramp blocks Emacs, and we need further debug information.
  

• Tramp supports lock files now.
  

  In order to deactivate this, set user option
  remote-file-name-inhibit-locks to t.
  

• Writing sensitive data locally requires confirmation.
  

  Writing auto-save, backup or lock files to the local temporary
  directory must be confirmed. In order to suppress this confirmation,
  set user option tramp-allow-unsafe-temporary-files to t.
  

• make-directory of a remote directory honors the default file modes.
  

2.6.36. GDB/MI

• New user option gdb-registers-enable-filter.
  

  If non-nil, apply a register filter based on
  gdb-registers-filter-pattern-list.
  

• gdb-mi can now save and restore window configurations.
  

  Use gdb-save-window-configuration to save window configuration to a
  file and gdb-load-window-configuration to load from a file. These
  commands can also be accessed through the menu bar under "Gud =>
  GDB-Windows". gdb-default-window-configuration-file, when non-nil,
  is loaded when GDB starts up.
  

• gdb-mi can now restore window configuration after quitting.
  

  Set gdb-restore-window-configuration-after-quit to non-nil and Emacs
  will remember the window configuration before GDB started and restore
  it after GDB quits. A toggle button is also provided under "Gud =>
  GDB-Windows" menu item.
  

• gdb-mi now has a better logic for displaying source buffers.
  

  Now GDB only uses one source window to display source file by default.
  Customize gdb-max-source-window-count to use more than one window.
  Control source file display by gdb-display-source-buffer-action.
  

• The default value of gdb-mi-decode-strings is now t.
  

  This means that the default coding-system is now used to decode strings
  and source file names from GDB.
  

2.6.37. Compilation mode

• New function ansi-color-compilation-filter.
  

  This function is meant to be used in compilation-filter-hook.
  

• New user option ansi-color-for-compilation-mode.
  

  This controls what ansi-color-compilation-filter does.
  

• Regexp matching of messages is now case-sensitive by default.
  

  The variable compilation-error-case-fold-search can be set for
  case-insensitive matching of messages when the old behavior is
  required, but the recommended solution is to use a correctly matching
  regexp instead.
  

• New user option compilation-search-all-directories.
  

  When doing parallel builds, directories and compilation errors may
  arrive in the *compilation* buffer out-of-order. If this option is
  non-nil (the default), Emacs will now search backwards in the buffer
  for any directory the file with errors may be in. If nil, this won't
  be done (and this restores how this previously worked).
  

• Messages from ShellCheck are now recognized.
  
• Messages from Visual Studio that mention column numbers are now recognized.
  

2.6.38. Hi Lock mode

• Matching in hi-lock-mode can be case-sensitive.
  

  The matching is case-sensitive when a regexp contains upper case
  characters and search-upper-case is non-nil. highlight-phrase
  also uses search-whitespace-regexp to substitute spaces in regexp
  search.
  

• The default value of hi-lock-highlight-range was enlarged.
  

  The new default value is 2000000 (2 megabytes).
  

2.6.39. Whitespace mode

• New style missing-newline-at-eof.
  

  If present in whitespace-style (as it is by default), the final
  character in the buffer will be highlighted if the buffer doesn't end
  with a newline.
  

• The default whitespace-enable-predicate predicate has changed.
  

  It used to check elements in the list version of
  whitespace-global-modes with eq, but now uses derived-mode-p.
  

2.6.40. Texinfo

• New user option texinfo-texi2dvi-options.
  

  This is used when invoking texi2dvi from texinfo-tex-buffer.
  

• New commands for moving in and between environments.
  

  An "environment" is something that ends with @end. The commands are
  C-c C-c C-f (next end), C-c C-c C-b (previous end),
  C-c C-c C-n (next start) and C-c C-c C-p (previous start), as well
  as C-c ., which will alternate between the start and the end of the
  current environment.
  

2.6.41. Rmail

• New user option rmail-re-abbrevs.
  

  Its default value matches localized abbreviations of the "reply"
  prefix on the Subject line in various languages.
  

• New user option rmail-show-message-set-modified.
  

  If set non-nil, showing an unseen message will set the Rmail buffer's
  modified flag. The default is nil, to preserve the old behavior.
  

2.6.42. CC mode

• Added support for Doxygen documentation style.
  

  doxygen is now a valid c-doc-comment-style which recognizes all
  comment styles supported by Doxygen (namely ///, //!, /** … */
  and /*! … */. gtkdoc remains the default for C and C++ modes; to
  use doxygen by default one might evaluate:
  

  (setq-default c-doc-comment-style
                '((java-mode . javadoc)
                  (pike-mode . autodoc)
                  (c-mode    . doxygen)
                  (c++-mode  . doxygen)))
  

  or use it in a custom c-style.
  

• Added support to line up ? and : of a ternary operator.
  

  The new c-lineup-ternary-bodies function can be used as a lineup
  function to align question mark and colon which are part of a ternary
  operator (?:). For example:
  

  return arg % 2 == 0 ? arg / 2
                      : (3 * arg + 1);
  

  To enable, add it to appropriate entries in c-offsets-alist, e.g.:
  

  (c-set-offset 'arglist-cont '(c-lineup-ternary-bodies
                                c-lineup-gcc-asm-reg))
  (c-set-offset 'arglist-cont-nonempty '(c-lineup-ternary-bodies
                                         c-lineup-gcc-asm-reg
                                         c-lineup-arglist))
  (c-set-offset 'statement-cont '(c-lineup-ternary-bodies +))
  

2.6.43. Images

• You can explicitly specify base_uri for svg images.
  

  :base-uri image property can be used to explicitly specify base_uri
  for embedded images into svg. :base-uri is supported for both file
  and data svg images.
  

• svg-embed-base-uri-image added to embed images.
  

  svg-embed-base-uri-image can be used to embed images located
  relatively to file-name-directory of the :base-uri svg image property.
  This works much faster than svg-embed.
  

• New function image-cache-size.
  

  This function returns the size of the current image cache, in bytes.
  

• Animated images stop automatically under high CPU pressure sooner.
  

  Previously, an animated image would stop animating if any single image
  took more than two seconds to display. The new algorithm maintains a
  decaying average of delays, and if this number gets too high, the
  animation is stopped.
  

• The n and p commands (next/previous image) now respect Dired order.
  

  These commands would previously display the next/previous image in
  lexicographic order, but will now find the "parent" Dired buffer and
  select the next/previous image file according to how the files are
  sorted there. The commands have also been extended to work when the
  "parent" buffer is an archive mode (i.e., zip file or the like) or tar
  mode buffer.
  

• image-converter is now restricted to formats in auto-mode-alist.
  

  When using external image converters, the external program is queried
  for what formats it supports. This list may contain formats that are
  problematic in some contexts (like PDFs), so this list is now filtered
  based on auto-mode-alist. Only file names that map to image-mode
  are now supported.
  

• The background and foreground of images now default to face colors.
  

  When an image doesn't specify a foreground or background color, Emacs
  now uses colors from the face used to draw the surrounding text
  instead of the frame's default colors.
  

  To load images with the default frame colors use the :foreground and
  :background image attributes, for example:
  

  (create-image "filename" nil nil
                :foreground (face-attribute 'default :foreground)
                :background (face-attribute 'default :background))
  

  This change only affects image types that support foreground and
  background colors or transparency, such as xbm, pbm, svg, png and gif.
  

• Image smoothing can now be explicitly enabled or disabled.
  

  Smoothing applies a bilinear filter while scaling or rotating an image
  to prevent aliasing and other unwanted effects. The new image
  property :transform-smoothing can be set to t to force smoothing
  and nil to disable smoothing.
  

  The default behavior of smoothing on down-scaling and not smoothing
  on up-scaling remains unchanged.
  

• New user option image-transform-smoothing.
  

  This controls whether to use smoothing or not for an image. Values
  include nil (no smoothing), t (do smoothing) or a predicate function
  that's called with the image object and should return nil/t.
  

• SVG images now support user stylesheets.
  

  The :css image attribute can be used to override the default CSS
  stylesheet for an image. The default sets font-family and
  font-size to match the current face, so an image with height="1em"
  will match the font size in use where it is embedded.
  

  This feature relies on librsvg 2.48 or above being available.
  

• Image properties support em sizes.
  

  Size image properties, for example :height, :max-height, etc., can
  be given a cons of the form (SIZE . em), where SIZE is an integer or
  float which is multiplied by the font size to calculate the image
  size, and em is a symbol.
  

2.6.44. EWW

• New user option eww-use-browse-url.
  

  This is a regexp that can be set to alter how links are followed in eww.
  

• New user option eww-retrieve-command.
  

  This can be used to download data via an external command. If nil
  (the default), then url-retrieve is used. When sync, then
  url-retrieve-synchronously is used. A list of strings specifies
  an external program with parameters.
  

• New Emacs command line convenience command.
  

  The eww-browse command has been added, which allows you to register
  Emacs as a MIME handler for "text/x-uri", and will call eww on the
  supplied URL. Usage example: "emacs -f eww-browse https://gnu.org".
  

• eww-download-directory will now use the XDG location, if defined.
  

  However, if "~/Downloads/" already exists, that will continue to be
  used.
  

• The command eww-follow-link now supports custom mailto: handlers.
  

  The function that is invoked when clicking on or otherwise following a
  mailto: link in an EWW buffer can now be customized. For more
  information, see the related entry about shr-browse-url below.
  

• Support for bookmark.el.
  

  The command bookmark-set (bound to C-x r m) is now supported, and
  will create a bookmark that opens the current URL in EWW.
  

2.6.45. SHR

• The command shr-browse-url now supports custom mailto: handlers.
  

  Clicking on or otherwise following a mailto: link in an HTML buffer
  rendered by SHR previously invoked the command browse-url-mail.
  This is still the case by default, but if you customize
  browse-url-mailto-function or browse-url-handlers to call some
  other function, it will now be called instead of the default.
  

• New user option shr-offer-extend-specpdl.
  

  If this is nil, rendering of HTML that requires enlarging
  max-specpdl-size, the number of Lisp variable bindings, will be
  aborted, and Emacs will not ask you whether to enlarge
  max-specpdl-size to complete the rendering. The default is t, which
  preserves the original behavior.
  

• New user option shr-max-width.
  

  If this user option is non-nil, and shr-width is nil, then SHR will
  use the value of shr-max-width to limit the width of the rendered
  HTML. The default is 120 characters, so even if you have very wide
  frames, HTML text will be rendered more narrowly, which usually leads
  to a more readable text. Customize it to nil to get the previous
  behavior of rendering as wide as the window-width allows. If
  shr-width is non-nil, it overrides this option.
  

• New faces for heading elements.
  

  Those are shr-h1, shr-h2, shr-h3, shr-h4, shr-h5, shr-h6.
  

2.6.46. Project

• New user option project-vc-merge-submodules.
  
• Project commands now have their own history.
  

  Previously used project directories are now suggested by all commands
  that prompt for a project directory.
  

• New prefix keymap project-prefix-map.
  

  Key sequences that invoke project-related commands start with the
  prefix C-x p. Type C-x p C-h to show the full list.
  

• New commands project-dired, project-vc-dir, project-shell,
  

  project-eshell. These commands run Dired/VC-Dir and Shell/Eshell in
  a project's root directory, respectively.
  

• New command project-compile.
  

  This command runs compilation in the current project's root directory.
  

• New command project-switch-project.
  

  This command lets you "switch" to another project and run a project
  command chosen from a dispatch menu.
  

• New commands project-shell-command and project-async-shell-command.
  

  These commands run shell-command and async-shell-command in a
  project's root directory, respectively.
  

• New user option project-list-file.
  

  This specifies the file in which to save the list of known projects.
  

• New command project-remember-projects-under.
  

  This command can automatically locate and index projects in a
  directory and optionally also its subdirectories, storing them in
  project-list-file.
  

• New commands project-forget-project and project-forget-projects-under.
  

  These commands let you interactively remove entries from the list of projects
  in project-list-file.
  

• New command project-forget-zombie-projects.
  

  This command detects indexed projects that have since been deleted,
  and removes them from the list of known projects in project-list-file.
  

• project-find-file now accepts non-existent file names.
  

  This is to allow easy creation of files inside some nested
  sub-directory.
  

• project-find-file doesn't use the string at point as default input.
  

  Now it's only suggested as part of the "future history", accessible
  via M-n.
  

• New command project-find-dir runs Dired in a directory inside project.
  

2.6.47. Xref

• New user options to automatically show the first Xref match.
  

  The new user option xref-auto-jump-to-first-definition controls the
  behavior of xref-find-definitions and its variants, like
  xref-find-definitions-other-window': if it's t or 'show, the first
  match is automatically displayed; if it's move, point in the
  *xref* buffer is automatically moved to the first match without
  displaying it.
  The new user option xref-auto-jump-to-first-xref changes the
  behavior of Xref commands such as xref-find-references,
  xref-find-apropos, and project-find-regexp, which are expected to
  display many matches that the user would like to
  visit. xref-auto-jump-to-first-xref changes their behavior much in
  the same way as xref-auto-jump-to-first-definition affects the
  xref-find-definitions* commands.
  

• New user options xref-search-program and xref-search-program-alist.
  

  So far grep and ripgrep are supported. ripgrep seems to offer better
  performance in certain cases, in particular for case-insensitive
  searches.
  

• New commands xref-prev-group and xref-next-group.
  

  These commands are bound respectively to P and N, and navigate to
  the first item of the previous or next group in the *xref* buffer.
  

• New alternative value for xref-show-definitions-function:
  

  xref-show-definitions-completing-read.
  

• The two existing alternatives for xref-show-definitions-function
  

  have been renamed to have "proper" public names and documented
  (xref-show-definitions-buffer and
  xref-show-definitions-buffer-at-bottom).
  

• New command xref-quit-and-pop-marker-stack.
  

  This command is bound to M-, in *xref* buffers. This combination
  is easy to press semi-accidentally if the user wants to go back in the
  middle of choosing the exact definition to go to, and this should do
  TRT.
  

• New value project-relative for xref-file-name-display.
  

  If chosen, file names in *xref* buffers will be displayed relative
  to the project-root of the current project, when available.
  

• Prefix arg of xref-goto-xref quits the *xref* buffer.
  

  So typing C-u RET in the *xref* buffer quits its window
  before navigating to the selected location.
  

• The TAB key binding in *xref* buffers is obsolete.
  

  Use C-u RET instead. The TAB binding in *xref* buffers is still
  supported, but we plan on removing it in a future version; at that
  time, the command xref-quit-and-goto-xref will no longer have a key
  binding in xref--xref-buffer-mode-map.
  

• New user option etags-xref-prefer-current-file.
  

  When non-nil, matches for identifiers in the file visited by the
  current buffer will be shown first in the *xref* buffer.
  

• The etags Xref backend now honors tags-apropos-additional-actions.
  

  You can customize it to augment the output of xref-find-apropos,
  like it affected the output of tags-apropos, which is obsolete since
  Emacs 25.1.
  

2.6.48. Battery

• UPower is now the default battery status backend when available.
  

  UPower support via the function battery-upower was added in Emacs
  26.1, but was disabled by default. It is now the default value of
  battery-status-function when the system provides a UPower D-Bus
  service. The user options battery-upower-device and
  battery-upower-subscribe control which power sources to query and
  whether to respond to status change notifications in addition to
  polling, respectively.
  

• A richer syntax can be used to format battery status information.
  

  The user options battery-mode-line-format and
  battery-echo-area-format now support the full formatting syntax of
  the function format-spec documented under node "(elisp) Custom Format
  Strings". The new syntax includes specifiers for padding and
  truncation, amongst other things.
  

2.6.49. Bug Reference

• Bug reference mode uses auto-setup.
  

  If bug-reference-mode or bug-reference-prog-mode have been
  activated, their respective hook has been run, and both
  bug-reference-bug-regexp and bug-reference-url-format are still
  not set, it tries to guess appropriate values for those two variables.
  There are three guessing mechanisms so far: based on version control
  information of the current buffer's file, based on
  newsgroup/mail-folder name and several news and mail message headers
  in Gnus buffers, and based on IRC channel and network in rcirc and ERC
  buffers. All the mechanisms are extensible with custom rules, see the
  variables bug-reference-setup-from-vc-alist,
  bug-reference-setup-from-mail-alist, and
  bug-reference-setup-from-irc-alist.
  

2.6.50. HTML mode

• A new skeleton for adding relative URLs has been added.
  

  It's bound to the C-c C-c f keystroke, and prompts for a local file
  name.
  

2.6.51. Widget

• widget-choose now supports menus in extended format.
  
• The editable-list widget now supports moving items up and down.
  

  You can now move items up and down by deleting and then reinserting
  them, using the DEL and INS buttons respectively. This is useful
  in Custom buffers, for example, to change the order of the elements in
  a list.
  

2.6.52. Diff

• New face diff-changed-unspecified.
  

  This is used to highlight "changed" lines (those marked with !) in
  context diffs, when diff-use-changed-face is non-nil.
  

• New diff-mode font locking face diff-error.
  

  This face is used for error messages from diff.
  

• New command diff-refresh-hunk.
  

  This new command (bound to C-c C-l) regenerates the current hunk.
  

2.6.53. Thing at point

• New thing-at-point target: existing-filename.
  

  This is like filename, but is a full path, and is nil if the file
  doesn't exist.
  

• New thing-at-point target: string.
  

  If point is inside a string, it returns that string.
  

• New variable thing-at-point-provider-alist.
  

  This allows mode-specific alterations to how thing-at-point works.
  

• thing-at-point now respects fields.
  

  thing-at-point (and all functions that use it, like
  symbol-at-point) will narrow to the current field (if any) before
  trying to identify the thing at point.
  

• New function thing-at-mouse.
  

  This is like thing-at-point, but uses the mouse event position instead.
  

2.6.54. Image Dired

• New user option image-dired-thumb-visible-marks.
  

  If non-nil (the default), use the new face image-dired-thumb-mark
  for marked images.
  

• New command image-dired-delete-marked.
  
• image-dired-mouse-toggle-mark is now sensitive to the active region.
  

  If the region is active, this command now toggles Dired marks of all
  the thumbnails in the region.
  

2.6.55. Flymake mode

• New command flymake-show-project-diagnostics.
  

  This lists all diagnostics for buffers in the currently active
  project. The listing is similar to the one obtained by
  flymake-show-buffer-diagnostics, but adds a column for the
  project-relative file name. For backends which support it,
  flymake-show-project-diagnostics also lists diagnostics for files
  that have not yet been visited.
  

• New user options to customize Flymake's mode-line.
  

  The new user option flymake-mode-line-format is a mix of strings and
  symbols like flymake-mode-line-title, flymake-mode-line-exception
  and flymake-mode-line-counters. The new user option
  flymake-mode-line-counter-format is a mix of strings and symbols
  like flymake-mode-line-error-counter,
  flymake-mode-line-warning-counter and flymake-mode-line-note-counter.
  

2.6.56. Time

• display-time-world has been renamed to world-clock.
  

  world-clock creates a buffer with an updating time display using
  several time zones. It is hoped that the new names are more
  discoverable.
  

  The following commands have been renamed:
  

  display-time-world to world-clock
display-time-world-mode to world-clock-mode
display-time-world-display to world-clock-display
display-time-world-timer to world-clock-update
  

  The following user options have been renamed:
  

  display-time-world-list to world-clock-list
display-time-world-time-format to world-clock-time-format
display-time-world-buffer-name to world-clock-buffer-name
display-time-world-timer-enable to world-clock-timer-enable
display-time-world-timer-second to world-clock-timer-second
  

  The old names are now obsolete.
  

• world-clock-mode can no longer be turned on interactively.
  

  Use world-clock to turn on that mode.
  

2.6.57. Python mode

• New user option python-forward-sexp-function.
  

  This allows the user easier customization of whether to use block-based
  navigation or not.
  

• python-shell-interpreter now defaults to python3 on systems with python3.
  
• C-c C-r can now be used on arbitrary regions.
  

  The command previously extended the start of the region to the start
  of the line, but will now actually send the marked region, as
  documented.
  

2.6.58. Ruby mode

• ruby-use-smie is declared obsolete.
  

  SMIE is now always enabled and ruby-use-smie only controls whether
  indentation is done using SMIE or with the old ad-hoc code.
  

• Indentation has changed when ruby-align-chained-calls is non-nil.
  

  This previously used to align subsequent lines with the last sibling,
  but it now aligns with the first sibling (which is the preferred style
  in Ruby).
  

2.6.59. CPerl mode

• New face perl-heredoc, used for heredoc elements.
  
• The command cperl-set-style offers the new value "PBP".
  

  This value customizes Emacs to use the style recommended in Damian
  Conway's book "Perl Best Practices" for indentation and formatting
  of conditionals.
  

2.6.60. Perl mode

• New face perl-non-scalar-variable.
  

  This is used to fontify non-scalar variables.
  

2.6.61. Octave mode

• Line continuations in double-quoted strings now use a backslash.
  

  Typing C-M-j (bound to octave-indent-new-comment-line) now follows
  the behavior introduced in Octave 3.8 of using a backslash as a line
  continuation marker within double-quoted strings, and an ellipsis
  everywhere else.
  

2.6.62. EasyPG

2.6.63. Etags

• Etags now supports the Mercury programming language.
  

  See https://mercurylang.org.
  

• Etags command line option --declarations now has Mercury-specific behavior.
  

  All Mercury declarations are tagged by default. However, for
  compatibility with etags support for Prolog, predicates and
  functions appearing first in clauses will also be tagged if etags is
  invoked with the --declarations command-line option.
  

2.6.64. Comint

• Support for OSC escape sequences.
  

  Adding the new function comint-osc-process-output to
  comint-output-filter-functions enables the interpretation of OSC
  ("Operating System Command") escape sequences in comint buffers. By
  default, only OSC 8, for hyperlinks, and OSC 7, for directory
  tracking, are acted upon. Adding more entries to
  comint-osc-handlers allows a customized treatment of further escape
  sequences.
  

• comint-delete-output can now save deleted text in the kill-ring.
  

  Interactively, C-u C-c C-o triggers this new optional behavior.
  

2.6.65. ANSI color

• Colors are now defined by faces.
  

  ANSI SGR codes now have corresponding faces to describe their
  appearance, e.g. ansi-color-bold.
  

• Support for "bright" color codes.
  

  "Bright" ANSI color codes are now displayed when applying ANSI color
  filters using the color values defined by the faces
  ansi-color-bright-COLOR. In addition, bold text with regular ANSI
  colors can be displayed as "bright" if ansi-color-bold-is-bright is
  non-nil.
  

2.6.66. ERC

• Starting with Emacs 28.1 and ERC 5.4, see the ERC-NEWS file for
  

  user-visible changes in ERC.
  

2.6.67. Xwidget Webkit mode

• New xwidget commands.
  

  xwidget-webkit-uri (return the current URL), xwidget-webkit-title
  (return the current title), and xwidget-webkit-goto-history (goto a
  point in history).
  

• Downloading files from xwidget-webkit is now supported.
  

  The new user option xwidget-webkit-download-dir says where to download to.
  

• New command xwidget-webkit-clone-and-split-below.
  

  Open a new window below displaying the current URL.
  

• New command xwidget-webkit-clone-and-split-right.
  

  Open a new window to the right displaying the current URL.
  

• Pixel-based scrolling.
  

  The xwidget-webkit-scroll-up, xwidget-webkit-scroll-down commands
  now supports scrolling arbitrary pixel values. It now treats the
  optional 2nd argument as the pixel values to scroll.
  

• New commands for scrolling.
  

  The new commands xwidget-webkit-scroll-up-line,
  xwidget-webkit-scroll-down-line, xwidget-webkit-scroll-forward,
  xwidget-webkit-scroll-backward can be used to scroll webkit by the
  height of lines or width of chars.
  

• New user option xwidget-webkit-bookmark-jump-new-session.
  

  When non-nil, use a new xwidget webkit session after bookmark jump.
  Otherwise, it will use xwidget-webkit-last-session.
  

2.6.68. Checkdoc

• No longer warns about command substitutions by default.
  

  Checkdoc used to warn about "too many command substitutions" (as in
  "\\[foo-command]"), even if you only used ten of them in a docstring.
  On modern machines, you can have hundreds or thousands of command
  substitutions before it becomes a performance issue, so this warning
  is now disabled by default. To re-enable this warning, customize the
  user option checkdoc-max-keyref-before-warn.
  

• New user option checkdoc-column-zero-backslash-before-paren.
  

  Checkdoc warns if there is a left parenthesis in column zero of a
  documentation string. That warning can now be disabled by customizing
  this new user option to nil. This is useful if you don't expect
  your code to be edited with an Emacs older than version 27.1.
  

• Now checks the prompt format for yes-or-no-p.
  

  In addition to verifying the format of the prompt for y-or-n-p,
  checkdoc will now check the format of yes-or-no-p.
  

• New command checkdoc-dired.
  

  This can be used to run checkdoc on files from a Dired buffer.
  

• No longer checks for A- modifiers.
  

  Checkdoc recommends usage of command substitutions ("\\[foo-command]")
  in favor of writing keybindings like C-c f. It now no longer warns
  about the A- modifier as it is not used very much in practice, and
  this warning therefore mostly led to false positives.
  

2.6.69. Enriched mode

• C-a is by default no longer bound to beginning-of-line-text.
  

  This is so C-a works as in other modes, and in particular holding
  Shift while typing C-a, i.e. C-S-a, will now highlight the text.
  

2.6.70. Gravatar

• New user option gravatar-service for host to query for gravatars.
  

  Defaults to gravatar, with unicornify and libravatar as options.
  

2.6.71. MH-E mail handler for Emacs

• New names for mh-junk interactive functions.
  

  Function mh-junk-whitelist is renamed mh-junk-allowlist.
  Function mh-junk-blacklist is renamed mh-junk-blocklist.
  

• New binding for mh-junk-allowlist.
  

  The key binding for mh-junk-allowlist is changed from J w to J a.
  The old binding is supported but warns that it is obsolete.
  

• New names for some hooks.
  

  mh-whitelist-msg-hook is renamed mh-allowlist-msg-hook.
  mh-blacklist-msg-hook is renamed mh-blocklist-msg-hook.
  

• New names for some user options.
  

  User option mh-whitelist-preserves-sequences-flag is renamed
  mh-allowlist-preserves-sequences-flag.
  

• New names for some faces.
  

  Face mh-folder-blacklisted is renamed mh-folder-blocklisted.
  Face mh-folder-whitelisted is renamed mh-folder-allowlisted.
  

2.6.72. Rcirc

• rcirc now supports SASL authentication.
  
• #emacs on Libera.chat has been added to rcirc-server-alist.
  
• rcirc connects asynchronously.
  
• Integrate formatting into rcirc-send-string.
  

  The function now accepts a variable number of arguments.
  

• Deprecate rcirc-command in favor of rcirc-define-command.
  

  The new macro handles multiple and optional arguments.
  

• Add basic IRCv3 support.
  

  This includes support for the capabilities: server-time, batch,
  message-ids, invite-notify, multi-prefix and standard-replies.
  

• Add mouse property support to rcirc-track-minor-mode.
  
• Improve support for IRC markup codes.
  
• Check auth-sources for server passwords.
  
• Implement repeated reconnection strategy.
  

  See rcirc-reconnect-attempts.
  

2.6.73. MPC

• New command mpc-goto-playing-song.
  

  This command, bound to o in any mpc-mode buffer, moves point to
  the currently playing song in the *MPC-Songs* buffer.
  

• New user option mpc-cover-image-re.
  

  If non-nil, it is a regexp that should match a valid cover image.
  

2.6.74. Miscellaneous

• shell-script-mode now supports outline-minor-mode.
  

  The outline headings have lines that start with "###".
  

• fileloop will now skip missing files instead of signalling an error.
  
• tabulated-list-mode can now restore original display order.
  

  Many commands (like C-x C-b) are derived from tabulated-list-mode,
  and that mode allows the user to sort on any column. There was
  previously no easy way to get back to the original displayed order
  after sorting, but giving a -1 numerical prefix to the sorting command
  will now restore the original order.
  

• M-left and M-right now move between columns in tabulated-list-mode.
  
• New variable hl-line-overlay-priority.
  

  This can be used to change the priority of the hl-line overlays.
  

• New command mailcap-view-file.
  

  This command will open a viewer based on the file type, as determined
  by "~/.mailcap" and related files and variables.
  

• New user option remember-diary-regexp.
  
• New user option remember-text-format-function.
  
• New user option authinfo-hide-elements.
  

  This can be set to nil to inhibit hiding passwords in ".authinfo" files.
  

• hexl-mode scrolling commands now heed next-screen-context-lines.
  

  Previously, hexl-scroll-down and hexl-scroll-up would scroll
  up/down an entire window, but they now work more like the standard
  scrolling commands.
  

• New user option bibtex-unify-case-function.
  

  This new option allows the user to customize how case is converted
  when unifying entries.
  

• The user option bibtex-maintain-sorted-entries now permits
  

  user-defined sorting schemes.
  

• New user option reveal-auto-hide.
  

  If non-nil (the default), revealed text is automatically hidden when
  point leaves the text. If nil, the text is not hidden again. Instead the
  command reveal-hide-revealed can be used to hide all the revealed text.
  

• New user option ffap-file-name-with-spaces.
  

  If non-nil, find-file-at-point and friends will try to guess more
  expansively to identify a file name with spaces. Default value is
  nil.
  

• Two new commands for centering in doc-view-mode.
  

  The new commands doc-view-center-page-horizontally (bound to c h)
  and doc-view-center-page-vertically (bound to c v) center the page
  horizontally and vertically, respectively.
  

• tempo-define-template can now re-assign templates to tags.
  

  Previously, assigning a new template to an already defined tag had no
  effect.
  

• The width of the buffer-name column in list-buffers is now dynamic.
  

  The width now depends on the width of the window, but will never be
  wider than the length of the longest buffer name, except that it will
  never be narrower than 19 characters.
  

• New diary sexp diary-offset.
  

  It offsets another diary sexp by a number of days. This is useful
  when for example your organization has a committee meeting two days
  after every monthly meeting which takes place on the third Thursday,
  or if you would like to attend a virtual meeting scheduled in a
  different timezone causing a difference in the date.
  

• The old non-SMIE indentation of sh-mode has been removed.
  
• mspools-show is now autoloaded.
  
• Loading dunnet.el in batch mode doesn't start the game any more.
  

  Instead you need to do "emacs –batch -f dunnet" to start the game in
  batch mode.
  

2.7.1. New mode repeat-mode to allow shorter key sequences.

2.7.2. New themes modus-vivendi and modus-operandi.

2.7.3. Dictionary mode

2.7.4. Lisp Data mode

2.7.5. New global mode global-goto-address-mode.

2.7.6. transient.el

2.7.7. hierarchy.el

2.7.8. New major mode for displaying the "etc/AUTHORS" file.

2.8.1. Emacs now prints a backtrace when signaling an error in batch mode.

2.8.2. Some floating-point numbers are now handled differently by the Lisp reader.

2.8.3. equal no longer examines some contents of window configurations.

2.8.4. The lexical-binding local variable is always enabled.

2.8.5. &rest in argument lists must always be followed by a variable name.

2.8.6. kill-all-local-variables has changed how it handles non-symbol hooks.

2.8.7. Temporary buffers no longer run certain buffer hooks.

2.8.8. New face child-frame-border and frame parameter child-frame-border-width.

2.8.9. run-at-time now tries harder to implement the t TIME parameter.

2.8.10. parse-partial-sexp now signals an error if TO is smaller than FROM.

2.8.11. global-mode-string constructs should end with a space.

2.8.12. overlays-in now handles zero-length overlays slightly differently.

2.8.13. replace-match now runs modification hooks slightly later.

2.8.14. completing-read-default sets completion variables buffer-locally.

2.8.15. XML serialization functions now reject invalid characters.

2.8.16. JSON

• JSON number parsing is now stricter.
  

  Numbers with a leading plus sign, leading zeros, or a missing integer
  component are now rejected by json-read and friends. This makes
  them more compliant with the JSON specification and consistent with
  the native JSON parsing functions.
  

• JSON functions support the semantics of RFC 8259.
  

  The JSON functions json-serialize, json-insert,
  json-parse-string, and json-parse-buffer now implement some of the
  semantics of RFC 8259 instead of the earlier RFC 4627. In particular,
  these functions now accept top-level JSON values that are neither
  arrays nor objects.
  

• Some JSON encoding functions are now obsolete.
  

  The functions json-encode-number, json-encode-hash-table,
  json-encode-key, and json-encode-list are now obsolete.
  

  The first two are kept as aliases of json-encode, which should be
  used instead. Uses of json-encode-list should be changed to call
  one of json-encode, json-encode-alist, json-encode-plist, or
  json-encode-array instead.
  

• Native JSON functions now signal an error if libjansson is unavailable.
  

  This affects json-serialize, json-insert, json-parse-string,
  and json-parse-buffer. This can happen if Emacs was compiled with
  libjansson, but the DLL cannot be found and/or loaded by Emacs at run
  time. Previously, Emacs would display a message and return nil in
  these cases.
  

2.8.17. The use of positional arguments in define-minor-mode is obsolete.

2.8.18. pcomplete-ignore-case is now an obsolete alias of completion-ignore-case.

2.8.19. completions-annotations face is not used when the caller puts own face.

2.8.20. An active minibuffer now has major mode minibuffer-mode.

2.8.21. make-text-button no longer modifies text properties of its first argument.

2.8.22. Some properties from completion tables are now preserved.

2.8.23. dns-query now consistently uses Lisp integers to represent integers.

2.8.24. The &define keyword in an Edebug specification now disables backtracking.

2.8.25. The error ftp-error belongs also to category remote-file-error.

2.8.26. The WHEN argument of make-obsolete and related functions is mandatory.

2.8.27. inhibit-nul-byte-detection is renamed to inhibit-null-byte-detection.

2.8.28. Some functions are no longer considered safe by unsafep:

2.8.29. sql-*-statement-starters are no longer user options.

2.8.30. Some locale-related variables have been removed.

2.8.31. Function lm-maintainer is replaced with lm-maintainers.

2.8.32. facemenu.el is no longer preloaded.

2.8.33. facemenu-color-alist is now obsolete, and is not used.

2.8.34. The variable keyboard-type is obsolete and not dynamically scoped any more.

2.8.35. The values variable is now obsolete.

2.8.36. The load-dangerous-libraries variable is now obsolete.

2.8.37. The macro with-displayed-buffer-window is now obsolete.

2.8.38. The rfc2368.el library is now obsolete.

2.8.39. The inversion.el library is now obsolete.

2.8.40. The metamail.el library is now obsolete.

2.8.41. Edebug changes

• get-edebug-spec is obsolete, replaced by edebug-get-spec.
  
• The spec operator :name NAME is obsolete, use &name instead.
  
• The spec element function-form is obsolete, use form instead.
  
• New function def-edebug-elem-spec to define Edebug spec elements.
  

  These used to be defined with def-edebug-spec thus conflating the
  two name spaces, which lead to name collisions.
  The use of def-edebug-spec to define Edebug spec elements is
  declared obsolete.
  

2.8.42. The sb-image.el library is now obsolete.

2.8.43. Some libraries obsolete since Emacs 23 have been removed:

2.8.44. Some functions and variables obsolete since Emacs 23 have been removed:

2.8.45. Some functions and variables obsolete since Emacs 22 have been removed:

2.8.46. The obsolete function thread-alive-p has been removed.

2.8.47. The variable force-new-style-backquotes has been removed.

2.8.48. Some obsolete variable and function aliases in dbus.el have been removed.

2.8.49. find-function-source-path renamed and re-documented.

2.8.50. The macro vc-call no longer evaluates its second argument twice.

2.8.51. Xref migrated from EIEIO to cl-defstruct for its core objects.

2.9.1. The interactive syntax has been extended to allow listing applicable modes.

2.9.2. New declare forms to control completion of commands in M-x.

2.9.3. define-minor-mode now takes an :interactive argument.

2.9.4. define-derived-mode now takes an :interactive argument.

2.9.5. define-globalized-minor-mode now takes a :predicate parameter.

2.9.6. condition-case now allows for a success handler.

2.9.7. New function benchmark-call to measure the execution time of a function.

2.9.8. The value thrown to the exit label can now be a function.

2.9.9. The behavior of format-spec is now closer to that of format.

2.9.10. defvar detects the error of defining a variable currently lexically bound.

2.9.11. New variable inhibit-mouse-event-check.

2.9.12. New variable redisplay-skip-initial-frame to enable batch redisplay tests.

2.9.13. Doc strings can now link to customization groups.

2.9.14. Doc strings can now link to man pages.

2.9.15. Buffers can now be created with certain hooks disabled.

2.9.16. New command make-directory-autoloads.

2.9.17. Dragging a file into Emacs pushes the file name onto file-name-history.

2.9.18. The easymenu library is now preloaded.

2.9.19. The iso-transl library is now preloaded.

2.9.20. :safe settings in defcustom are now propagated to the loaddefs files.

2.9.21. New :type for defcustom for nonnegative integers.

2.9.22. ERT can now output more verbose test failure reports.

2.9.23. Byte compiler changes

• New byte-compiler check for missing dynamic variable declarations.
  

  It is meant as an (experimental) aid for converting Emacs Lisp code
  to lexical binding, where dynamic (special) variables bound in one
  file can affect code in another. For details, see the Info node
  "(elisp) Converting to Lexical Binding".
  

• byte-recompile-directory can now compile symlinked "*.el" files.
  

  This is achieved by giving a non-nil FOLLOW-SYMLINKS parameter.
  

• The byte-compiler now warns about too wide documentation strings.
  

  By default, it will warn if a documentation string is wider than the
  largest of byte-compile-docstring-max-column or fill-column
  characters.
  

• byte-compile-file optional argument LOAD is now obsolete.
  

  To load the file after byte-compiling, add a call to load from Lisp
  or use M-x emacs-lisp-byte-compile-and-load interactively.
  

2.9.24. Macroexp

• New function macroexp-file-name to know the name of the current file.
  
• New function macroexp-compiling-p to know if we're compiling.
  
• New function macroexp-warn-and-return to help emit warnings.
  

  This used to be named macroexp--warn-and-return and has proved useful
  and well-behaved enough to lose the "internal" marker.
  

2.9.25. map.el

• Alist keys are now consistently compared with equal by default.
  

  Until now, map-elt and map-delete compared alist keys with eq by
  default. They now use equal instead, for consistency with
  map-put! and map-contains-key.
  

• Pcase map pattern added keyword symbols abbreviation.
  

  A pattern like (map :sym) binds the map's value for :sym to sym,
  equivalent to (map (:sym sym)).
  

• The function map-copy now uses copy-alist on alists.
  

  This is a slightly deeper copy than the previous copy-sequence.
  

• The function map-contains-key now supports plists.
  
• More consistent duplicate key handling in map-merge-with.
  

  Until now, map-merge-with promised to call its function argument
  whenever multiple maps contained eql keys. However, this did not
  always coincide with the keys that were actually merged, which could
  be equal instead. The function argument is now called whenever keys
  are merged, for greater consistency with map-merge and map-elt.
  

2.9.26. Pcase

• The or pattern now binds the union of the vars of its sub-patterns.
  

  If a variable is not bound by the subpattern that matched, it gets bound
  to nil. This was already sometimes the case, but it is now guaranteed.
  

• The pred pattern can now take the form (pred (not FUN)).
  

  This is like (pred (lambda (x) (not (FUN x)))) but results
  in better code.
  

• New function pcase-compile-patterns to write other macros.
  
• Added cl-type pattern.
  

  The new cl-type pattern compares types using cl-typep, which allows
  comparing simple types like (cl-type integer), as well as forms like
  (cl-type (integer 0 10)).
  

• New macro pcase-setq.
  

  This macro is the setq equivalent of pcase-let, which allows for
  destructuring patterns in a setq form.
  

2.9.27. Edebug

• Edebug specification lists can use some new keywords:
  
  • &interpose SPEC FUN ARGS... lets FUN control parsing after SPEC.
    

    More specifically, FUN is called with HEAD PF ARGS... where
    PF is a parsing function that expects a single argument (the specs to
    use) and HEAD is the code that matched SPEC.
    

  • &error MSG unconditionally aborts the current edebug instrumentation.
    
  • &name SPEC FUN extracts the current name from the code matching SPEC.
    

2.9.28. Dynamic modules changes

• Type aliases for module functions and finalizers.
  

  The module header "emacs-module.h" now contains type aliases
  emacs_function and emacs_finalizer for module functions and
  finalizers, respectively.
  

• Module functions can now be made interactive.
  

  Use make_interactive to give a module function an interactive
  specification.
  

• Module functions can now install an optional finalizer.
  

  The finalizer is called when the function object is garbage-collected.
  Use set_function_finalizer to set the finalizer and
  get_function_finalizer to retrieve it.
  

• Modules can now open a channel to an existing pipe process.
  

  Modules can use the new module function open_channel to do that.
  On capable systems, modules can use this functionality to
  asynchronously send data back to Emacs.
  

• A new module API make_unibyte_string.
  

  It can be used to create Lisp strings with arbitrary byte sequences
  (a.k.a. "raw bytes").
  

2.9.29. Shorthands for Lisp symbols.

2.9.30. New function string-search.

2.9.31. New function string-replace.

2.9.32. New function ensure-list.

2.9.33. New function split-string-shell-command.

2.9.34. New function string-clean-whitespace.

2.9.35. New function string-fill.

2.9.36. New function string-limit.

2.9.37. New function string-lines.

2.9.38. New function string-pad.

2.9.39. New function string-chop-newline.

2.9.40. New function replace-regexp-in-region.

2.9.41. New function replace-string-in-region.

2.9.42. New function file-name-with-extension.

2.9.43. New function file-modes-number-to-symbolic to convert a numeric

2.9.44. New function file-name-concat.

2.9.45. New function file-backup-file-names.

2.9.46. New function directory-empty-p.

2.9.47. New function buffer-local-boundp.

2.9.48. New function always.

2.9.49. New function sxhash-equal-including-properties.

2.9.50. New function buffer-line-statistics.

2.9.51. New function color-values-from-color-spec.

2.9.52. New function custom-add-choice.

2.9.53. New function decoded-time-period.

2.9.54. New function dom-print.

2.9.55. New function dom-remove-attribute.

2.9.56. New function dns-query-asynchronous.

2.9.57. New function garbage-collect-maybe to trigger GC early.

2.9.58. New function get-locale-names.

2.9.59. New function insert-into-buffer.

2.9.60. New function json-available-p.

2.9.61. New function mail-header-parse-addresses-lax.

2.9.62. New function mail-header-parse-address-lax.

2.9.63. New function make-separator-line.

2.9.64. New function num-processors.

2.9.65. New function object-intervals.

2.9.66. New function process-lines-ignore-status.

2.9.67. New function require-theme.

2.9.68. New function seq-union.

2.9.69. New function syntax-class-to-char.

2.9.70. New functions null-device and path-separator.

2.9.71. New predicate functions length<, length> and length=.

2.9.72. New macro dlet to dynamically bind variables.

2.9.73. New macro with-existing-directory.

2.9.74. New variable current-minibuffer-command.

2.9.75. New variable inhibit-interaction to make user prompts signal an error.

2.9.76. New variable indent-line-ignored-functions.

2.9.77. New variable print-integers-as-characters modifies integer printing.

2.9.78. New variable tty-menu-calls-mouse-position-function.

2.9.79. New variables that hold default buffer names for shell output.

2.9.80. New variables read-char-choice-use-read-key and y-or-n-p-use-read-key.

2.9.81. New variable global-minor-modes.

2.9.82. New buffer-local variable local-minor-modes.

2.9.83. New completion function affixation-function to add prefix/suffix.

2.9.84. New completion function group-function for grouping candidates.

2.9.85. New error symbol minibuffer-quit.

2.9.86. New error symbol remote-file-error, a subcategory of file-error.

(setq debug-ignored-errors
      (cons 'remote-file-error debug-ignored-errors))

2.9.87. New macro named-let.

2.9.88. Emacs now attempts to test for high-rate subprocess output more fairly.

2.9.89. set-process-buffer now updates the process mark.

2.9.90. unlock-buffer displays warnings instead of signaling.

2.9.91. read-char-from-minibuffer and y-or-n-p support help-form.

2.9.92. read-number now has its own history variable.

2.9.93. set-window-configuration now takes two optional parameters,

2.9.94. count-windows now takes an optional parameter ALL-FRAMES.

2.9.95. truncate-string-ellipsis now uses … by default.

2.9.96. string-width now accepts two optional arguments FROM and TO.

2.9.97. directory-files now takes an additional COUNT parameter.

2.9.98. count-lines can now ignore invisible lines.

2.9.99. count-words now crosses field boundaries.

2.9.100. File-related APIs can optionally follow symlinks.

2.9.101. format-seconds can now be used for sub-second times.

2.9.102. parse-time-string can now parse ISO 8601 format strings.

2.9.103. lookup-key is more allowing when searching for extended menu items.

2.9.104. make-network-process, make-serial-process ':coding' behavior change.

2.9.105. open-network-stream now accepts a :coding argument.

2.9.106. open-network-stream can now take a :capability-command that's a function.

2.9.107. open-gnutls-stream now also accepts a :coding argument.

2.9.108. process-attributes now works under OpenBSD, too.

2.9.109. format-spec now takes an optional SPLIT parameter.

2.9.110. unload-feature now also tries to undo additions to buffer-local hooks.

2.9.111. while-no-input-ignore-events accepts more special events.

2.9.112. start-process-shell-command and start-file-process-shell-command

2.9.113. yes-or-no-p and y-or-n-p PROMPT parameter no longer needs trailing space.

2.9.114. The UNIQUIFY argument in auto-save-file-name-transforms can be a symbol.

2.9.115. New user option process-file-return-signal-string.

2.9.116. EIEIO Changes

• The macro oref-default can now be used with setf.
  

  It is now defined as a generalized variable that can be used with
  setf to modify the value stored in a given class slot.
  

• form in (eql form) specializers in cl-defmethod is now evaluated.
  

  This corresponds to the behavior of defmethod in Common Lisp Object System.
  For compatibility, (eql SYMBOL) does not evaluate SYMBOL, for now.
  

2.9.117. D-Bus

• Property values can be typed explicitly.
  

  dbus-register-property and dbus-set-property accept now optional
  type symbols. Both functions propagate D-Bus errors.
  

• Registered properties can have the new access type :write.
  
• In case of problems, handlers can emit proper D-Bus error messages now.
  
• D-Bus errors, which have been converted from incoming D-Bus error
  

  messages, contain the error name of that message now.
  

• D-Bus messages can be monitored with the new command dbus-monitor.
  
• D-Bus events have changed their internal structure.
  

  They carry now the destination and the error-name of an event. They
  also keep the type information of their arguments. Use the
  dbus-event-* accessor functions.
  

2.9.118. Buttons

• New minor mode button-mode.
  

  This minor mode does nothing except install button-buffer-map as
  a minor mode map (which binds the TAB / S-TAB key bindings to navigate
  to buttons), and can be used in any view-mode-like buffer that has
  buttons in it.
  

• New utility function button-buttonize.
  

  This function takes a string and returns a string propertized in a way
  that makes it a valid button.