When you add a new item, use the appropriate mark if you are sure it applies,
\f
-* Installation Changes in Emacs 26.1
-
-** By default libgnutls is now required when building Emacs.
-Use 'configure --with-gnutls=no' to build even when GnuTLS is missing.
-
-** GnuTLS version 2.12.2 or later is now required, instead of merely
-version 2.6.6 or later.
-
-** The new option 'configure --with-mailutils' causes Emacs to rely on
-GNU Mailutils to retrieve email. It is recommended, and is the
-default if GNU Mailutils is installed. When --with-mailutils is not
-in effect, the Emacs build procedure by default continues to build and
-install a limited 'movemail' substitute that retrieves POP3 email only
-via insecure channels; to avoid this problem, use either
---with-mailutils or --without-pop when configuring.
-
-** The new option 'configure --enable-gcc-warnings=warn-only' causes
-GCC to issue warnings without stopping the build. This behavior is
-now the default in developer builds. As before, use
-'--disable-gcc-warnings' to suppress GCC's warnings, and
-'--enable-gcc-warnings' to stop the build if GCC issues warnings.
-
-** When GCC warnings are enabled, '--enable-check-lisp-object-type' is
-now enabled by default when configuring.
-
-+++
-** The Emacs server now has socket-launching support. This allows
-socket based activation, where an external process like systemd can
-invoke the Emacs server process upon a socket connection event and
-hand the socket over to Emacs. Emacs uses this socket to service
-emacsclient commands. This new functionality can be disabled with the
-configure option '--disable-libsystemd'.
-
-+++
-** A systemd user unit file is provided. Use it in the standard way:
-systemctl --user enable emacs
-(If your Emacs is installed in a non-standard location, you may
-need to copy the emacs.service file to eg ~/.config/systemd/user/)
-
-** New configure option '--disable-build-details' attempts to build an
-Emacs that is more likely to be reproducible; that is, if you build
-and install Emacs twice, the second Emacs is a copy of the first.
-Deterministic builds omit the build date from the output of the
-'emacs-version' and 'erc-cmd-SV' functions, and the leave the
-following variables nil: 'emacs-build-system', 'emacs-build-time',
-'erc-emacs-build-time'.
-
----
-** Emacs can now be built with support for Little CMS.
-
-If the lcms2 library is installed, Emacs will enable features built on
-top of that library. The new configure option '--without-lcms2' can
-be used to build without lcms2 support even if it is installed. Emacs
-linked to Little CMS exposes color management functions in Lisp: the
-color metrics 'lcms-cie-de2000' and 'lcms-cam02-ucs'.
-
-** The configure option '--with-gameuser' now defaults to 'no',
-as this appears to be the most common configuration in practice.
-When it is 'no', the shared game directory and the auxiliary program
-update-game-score are no longer needed and are not installed.
-
-** Emacs no longer works on IRIX. We expect that Emacs users are not
-affected by this, as SGI stopped supporting IRIX in December 2013.
+* Installation Changes in Emacs 27.1
\f
-* Startup Changes in Emacs 26.1
-
-+++
-** New option '--fg-daemon'. This is the same as '--daemon', except
-it runs in the foreground and does not fork. This is intended for
-modern init systems such as systemd, which manage many of the traditional
-aspects of daemon behavior themselves. '--bg-daemon' is now an alias
-for '--daemon'.
-
-+++
-** New option '--module-assertions'.
-When given this option, Emacs will perform expensive correctness
-checks when dealing with dynamic modules. This is intended for module
-authors that wish to verify that their module conforms to the module
-requirements. The option makes Emacs abort if a module-related
-assertion triggers.
-
-+++
-** Emacs now supports 24-bit colors on capable text terminals
-Terminal is automatically initialized to use 24-bit colors if the
-required capabilities are found in terminfo. See the FAQ node
-"Colors on a TTY" for more information.
-
-+++
-** Emacs now obeys the X resource "scrollBar" at startup.
-The effect is similar to that of "toolBar" resource on the tool bar.
+* Startup Changes in Emacs 27.1
\f
-* Changes in Emacs 26.1
-
-+++
-** Option 'buffer-offer-save' can be set to new value, 'always'. When
- set to 'always', the command `save-some-buffers' will always offer
- this buffer for saving.
-
-** Security vulnerability related to Enriched Text mode is removed.
-
-+++
-*** Enriched Text mode does not evaluate Lisp in 'display' properties.
-This feature allows saving 'display' properties as part of text.
-Emacs 'display' properties support evaluation of arbitrary Lisp forms
-as part of processing the property for display, so displaying Enriched
-Text could be vulnerable to executing arbitrary malicious Lisp code
-included in the text (e.g., sent as part of an email message).
-Therefore, execution of arbitrary Lisp forms in 'display' properties
-decoded by Enriched Text mode is now disabled by default. Customize
-the new option 'enriched-allow-eval-in-display-props' to a non-nil
-value to allow Lisp evaluation in decoded 'display' properties.
-
-This vulnerability was introduced in Emacs 21.1. To work around that
-in Emacs versions before 25.3, append the following to your ~/.emacs
-init file:
-
- (eval-after-load "enriched"
- '(defun enriched-decode-display-prop (start end &optional param)
- (list start end)))
-
-+++
-** Functions in 'write-contents-functions' can fully short-circuit the
-'save-buffer' process. Previously, saving a buffer that was not
-visiting a file would always prompt for a file name. Now it only does
-so if 'write-contents-functions' is nil (or all its functions return
-nil).
-
----
-** New variable 'executable-prefix-env' for inserting magic signatures.
-This variable affects the format of the interpreter magic number
-inserted by 'executable-set-magic'. If non-nil, the magic number now
-takes the form "#!/usr/bin/env interpreter", otherwise the value
-determined by 'executable-prefix', which is by default
-"#!/path/to/interpreter". By default, 'executable-prefix-env' is nil,
-so the default behavior is not changed.
-
-+++
-** The variable 'emacs-version' no longer includes the build number.
-This is now stored separately in a new variable, 'emacs-build-number'.
-
-+++
-** Emacs now provides a limited form of concurrency with Lisp threads.
-Concurrency in Emacs Lisp is "mostly cooperative", meaning that
-Emacs will only switch execution between threads at well-defined
-times: when Emacs waits for input, during blocking operations related
-to threads (such as mutex locking), or when the current thread
-explicitly yields. Global variables are shared among all threads, but
-a 'let' binding is thread-local. Each thread also has its own current
-buffer and its own match data.
-
-See the chapter "Threads" in the ELisp manual for full documentation
-of these facilities.
-
-+++
-** The new user variable 'electric-quote-chars' provides a list
-of curved quotes for 'electric-quote-mode', allowing user to choose
-the types of quotes to be used.
-
----
-** The new user option 'electric-quote-context-sensitive' makes
-'electric-quote-mode' context sensitive. If it is non-nil, you can
-type an ASCII apostrophe to insert an opening or closing quote,
-depending on context. Emacs will replace the apostrophe by an opening
-quote character at the beginning of the buffer, the beginning of a
-line, after a whitespace character, and after an opening parenthesis;
-and it will replace the apostrophe by a closing quote character in all
-other cases.
-
----
-** The new variable 'electric-quote-inhibit-functions' controls when
-to disable electric quoting based on context. Major modes can add
-functions to this list; Emacs will temporarily disable
-'electric-quote-mode' whenever any of the functions returns non-nil.
-This can be used by major modes that derive from 'text-mode' but allow
-inline code segments, such as 'markdown-mode'.
-
-+++
-** The new user variable 'dired-omit-case-fold' allows the user to
-customize the case-sensitivity of dired-omit-mode. It defaults to
-the same sensitivity as that of the filesystem for the corresponding
-dired buffer.
-
-+++
-** Emacs now uses double buffering to reduce flicker when editing and
-resizing graphical Emacs frames on the X Window System. This support
-requires the DOUBLE-BUFFER extension, which major X servers have
-supported for many years. If your system has this extension, but an
-Emacs built with double buffering misbehaves on some displays you use,
-you can disable the feature by adding
-
- '(inhibit-double-buffering . t)
-
-to default-frame-alist. Or inject this parameter into the selected
-frame by evaluating this form:
-
- (modify-frame-parameters nil '((inhibit-double-buffering . t)))
-
----
-The group 'wp', whose label was "text", is now deprecated.
-Use the new group 'text', which inherits from 'wp', instead.
-
-+++
-** The new function 'call-shell-region' executes a command in an
-inferior shell with the buffer region as input.
-
-+++
-** The new user option 'shell-command-dont-erase-buffer' controls
-if the output buffer is erased between shell commands; if non-nil,
-the output buffer is not erased; this variable also controls where
-to set the point in the output buffer: beginning of the output,
-end of the buffer or save the point.
-When 'shell-command-dont-erase-buffer' is nil, the default value,
-the behavior of 'shell-command', 'shell-command-on-region' and
-'async-shell-command' is as usual.
-
-+++
-** The new user option 'async-shell-command-display-buffer' controls
-whether the output buffer of an asynchronous command is shown
-immediately, or only when there is output.
-
-+++
-** The new user option 'mouse-select-region-move-to-beginning'
-controls the position of point when double-clicking mouse-1 on the end
-of a parenthetical grouping or string-delimiter: the default value nil
-keeps point at the end of the region, setting it to non-nil moves
-point to the beginning of the region.
-
-+++
-** The new user option 'mouse-drag-and-drop-region' allows to drag the
-entire region of text to another place or another buffer.
-
-+++
-** The new user option 'confirm-kill-processes' allows the user to
-skip a confirmation prompt for killing subprocesses when exiting
-Emacs. When set to t (the default), Emacs will prompt for
-confirmation before killing subprocesses on exit, which is the same
-behavior as before.
-
----
-** 'find-library-name' will now fall back on looking at 'load-history'
-to try to locate libraries that have been loaded with an explicit path
-outside 'load-path'.
-
-+++
-** Faces in 'minibuffer-prompt-properties' no longer overwrite properties
-in the text in functions like 'read-from-minibuffer', but instead are
-added to the end of the face list. This allows users to say things
-like '(read-from-minibuffer (propertize "Enter something: " 'face 'bold))'.
-
-+++
-** The new variable 'extended-command-suggest-shorter' has been added
-to control whether to suggest shorter 'M-x' commands or not.
-
----
-** icomplete now respects 'completion-ignored-extensions'.
-
-+++
-** Non-breaking hyphens are now displayed with the 'nobreak-hyphen'
-face instead of the 'escape-glyph' face.
-
-+++
-** Approximations to quotes are now displayed with the new 'homoglyph'
-face instead of the 'escape-glyph' face.
-
-+++
-** New face 'header-line-highlight'.
-This face is the header-line analogue of 'mode-line-highlight'; it
-should be the preferred mouse-face for mouse-sensitive elements in the
-header line.
-
----
-** 'C-x h' ('mark-whole-buffer') will now avoid marking the prompt
-part of minibuffers.
-
----
-** 'find-library' now takes a prefix argument to pop to a different
-window.
-
----
-** 'fill-paragraph' no longer marks the buffer as changed unless it
-actually changed something.
-
----
-** The locale language name 'ca' is now mapped to the language
-environment 'Catalan', which has been added.
-
----
-** 'align-regexp' has a separate history for its interactive argument.
-'align-regexp' no longer shares its history with all other
-history-less functions that use 'read-string'.
-
-+++
-** The networking code has been reworked so that it's more
-asynchronous than it was (when specifying :nowait t in
-'make-network-process'). How asynchronous it is varies based on the
-capabilities of the system, but on a typical GNU/Linux system the DNS
-resolution, the connection, and (for TLS streams) the TLS negotiation
-are all done without blocking the main Emacs thread. To get
-asynchronous TLS, the TLS boot parameters have to be passed in (see
-the manual for details).
-
-Certain process oriented functions (like 'process-datagram-address')
-will block until socket setup has been performed. The recommended way
-to deal with asynchronous sockets is to avoid interacting with them
-until they have changed status to "run". This is most easily done
-from a process sentinel.
-
----
-** 'make-network-process' and 'open-network-stream' sometimes allowed
-:service to be an integer string (e.g., :service "993") and sometimes
-required an integer (e.g., :service 993). This difference has been
-eliminated, and integer strings work everywhere.
-
----
-** It is possible to disable attempted recovery on fatal signals.
-Two new variables support disabling attempts to recover from stack
-overflow and to avoid automatic auto-save when Emacs is delivered a
-fatal signal. 'attempt-stack-overflow-recovery', if set to 'nil',
-will disable attempts to recover from C stack overflows; Emacs will
-then crash as with any other fatal signal.
-'attempt-orderly-shutdown-on-fatal-signal', if set to 'nil', will
-disable attempts to auto-save the session and shut down in an orderly
-fashion when Emacs receives a fatal signal; instead, Emacs will
-terminate immediately. Both variables are non-'nil' by default.
-These variables are for users who would like to avoid the small
-probability of data corruption due to techniques Emacs uses to recover
-in these situations.
-
-+++
-** File local and directory local variables are now initialized each
-time the major mode is set, not just when the file is first visited.
-These local variables will thus not vanish on setting a major mode.
-
-+++
-** A second dir-local file (.dir-locals-2.el) is now accepted.
-See the variable 'dir-locals-file-2' for more information.
-
-+++
-** Connection-local variables can be used to specify local variables
-with a value depending on the connected remote server. For details,
-see the node "Connection Local Variables" in the ELisp manual.
-
----
-** International domain names (IDNA) are now encoded via the new
-puny.el library, so that one can visit Web sites with non-ASCII URLs.
-
-+++
-** The new 'list-timers' command lists all active timers in a buffer,
-where you can cancel them with the 'c' command.
-
-+++
-** 'switch-to-buffer-preserve-window-point' now defaults to t.
-
-+++
-** The new variable 'debugger-stack-frame-as-list' allows displaying
-all call stack frames in a Lisp backtrace buffer as lists. Both
-debug.el and edebug.el have been updated to heed to this variable.
-
----
-** Values in call stack frames are now displayed using 'cl-prin1'.
-The old behaviour of using 'prin1' can be restored by customizing the
-new option 'debugger-print-function'.
-
-+++
-** NUL bytes in text copied to the system clipboard are now replaced with "\0".
-
-+++
-** The new variable 'x-ctrl-keysym' has been added to the existing
-roster of X keysyms. It can be used in combination with another
-variable of this kind to swap modifiers in Emacs.
-
----
-** New input methods: 'cyrillic-tuvan', 'polish-prefix'.
-
----
-** The 'dutch' input method no longer attempts to support Turkish too.
-Also, it no longer converts 'IJ' and 'ij' to the compatibility
-characters U+0132 LATIN CAPITAL LIGATURE IJ and U+0133 LATIN SMALL
-LIGATURE IJ.
-
-+++
-** File name quoting by adding the prefix "/:" is now possible for the
-local part of a remote file name. Thus, if you have a directory named
-"/~" on the remote host "foo", you can prevent it from being
-substituted by a home directory by writing it as "/foo:/:/~/file".
-
-+++
-** The new variable 'maximum-scroll-margin' allows having effective
-settings of 'scroll-margin' up to half the window size, instead of
-always restricting the margin to a quarter of the window.
-
-+++
-** Emacs can scroll horizontally using mouse, touchpad, and trackbar.
-You can enable this by customizing 'mwheel-tilt-scroll-p'. If you
-want to reverse the direction of the scroll, customize
-'mwheel-flip-direction'.
-
-+++
-** Emacsclient has a new option -u/--suppress-output.
-This option suppresses display of return values from the server
-process.
-
-+++
-** Emacsclient has a new option -T/--tramp.
-This helps with using a local Emacs session as the server for a remote
-emacsclient. With appropriate setup, one can now set the EDITOR
-environment variable on a remote machine to emacsclient, and
-use the local Emacs to edit remote files via Tramp. See the node
-"emacsclient Options" in the user manual for the details.
-
----
-** New user option 'dig-program-options' and extended functionality
-for DNS-querying functions 'nslookup-host', 'dns-lookup-host',
-and 'run-dig'. Each function now accepts an optional name server
-argument interactively (with a prefix argument) and non-interactively.
-
-+++
-** 'describe-key-briefly' now ignores mouse movement events.
-
-+++
-** The new variable 'eval-expression-print-maximum-character' prevents
-large integers from being displayed as characters by 'M-:' and similar
-commands.
-
----
-** Two new commands for finding the source code of Emacs Lisp
-libraries: 'find-library-other-window' and 'find-library-other-frame'.
-
-+++
-** The new variable 'display-raw-bytes-as-hex' allows to change the
-display of raw bytes from octal to hex.
-
-+++
-** You can now provide explicit field numbers in format specifiers.
-For example, '(format "%2$s %1$s" "X" "Y")' produces "Y X".
-
-+++
-** Emacs now supports optional display of line numbers in the buffer.
-This is similar to what linum-mode provides, but much faster and
-doesn't usurp the display margin for the line numbers. Customize the
-buffer-local variable 'display-line-numbers' to activate this optional
-display. Alternatively, you can use the `display-line-numbers-mode'
-minor mode or the global `global-display-line-numbers-mode'. When
-using these modes, customize `display-line-numbers-type' with the same
-value as you would use with `display-line-numbers'.
-
-Line numbers are not displayed at all in minibuffer windows and in
-tooltips, as they are not useful there.
-
-Lisp programs can disable line-number display for a particular screen
-line by putting the 'display-line-numbers-disable' text property or
-overlay property on the first character of that screen line. This is
-intended for add-on packages that need a finer control of the display.
-
-Lisp programs that need to know how much screen estate is used up for
-line-number display in a window can use the new function
-'line-number-display-width'.
-
-Linum mode and all similar packages are henceforth becoming obsolete.
-Users and developers are encouraged to switch to this new feature
-instead.
-
-+++
-** emacsclient now accepts command-line options in ALTERNATE_EDITOR
-and --alternate-editor. For example, ALTERNATE_EDITOR="emacs -Q -nw".
-Arguments may be quoted "like this", so that for example an absolute
-path containing a space may be specified; quote escaping is not
-supported.
+* Changes in Emacs 27.1
\f
-* Editing Changes in Emacs 26.1
-
-+++
-** New variable 'column-number-indicator-zero-based'.
-Traditionally, in Column Number mode, the displayed column number
-counts from zero starting at the left margin of the window. This
-behavior is now controlled by 'column-number-indicator-zero-based'.
-If you would prefer for the displayed column number to count from one,
-you may set this variable to nil. (Behind the scenes, there is now a
-new mode line construct, '%C', which operates exactly as '%c' does
-except that it counts from one.)
-
-+++
-** New single-line horizontal scrolling mode.
-The 'auto-hscroll-mode' variable can now have a new special value,
-'current-line', which causes only the line where the cursor is
-displayed to be horizontally scrolled when lines are truncated on
-display and point moves outside the left or right window margin.
-
-+++
-** New mode line constructs '%o' and '%q', and user option
-'mode-line-percent-position'. '%o' displays the "degree of travel" of
-the window through the buffer. Unlike the default '%p', this
-percentage approaches 100% as the window approaches the end of the
-buffer. '%q' displays the percentage offsets of both the start and
-the end of the window, e.g. "5-17%". The new option
-'mode-line-percent-position' makes it easier to switch between '%p',
-'%P', and these new constructs.
-
-+++
-** Two new user options 'list-matching-lines-jump-to-current-line' and
-'list-matching-lines-current-line-face' to show highlighted the current
-line in *Occur* buffer.
-
-+++
-** The 'occur' command can now operate on the region.
-
-+++
-** New bindings for 'query-replace-map'.
-'undo', undo the last replacement; bound to 'u'.
-'undo-all', undo all replacements; bound to 'U'.
-
----
-** 'delete-trailing-whitespace' deletes whitespace after form feed.
-In modes where form feed was treated as a whitespace character,
-'delete-trailing-whitespace' would keep lines containing it unchanged.
-It now deletes whitespace after the last form feed thus behaving the
-same as in modes where the character is not whitespace.
-
----
-** Emacs no longer prompts about editing a changed file when the file's
-content is unchanged. Instead of only checking the modification time,
-Emacs now also checks the file's actual content before prompting the user.
-
----
-** Various casing improvements.
-
-*** 'upcase', 'upcase-region' et al. convert title case characters
-(such as Dz) into their upper case form (such as DZ).
-
-*** 'capitalize', 'upcase-initials' et al. make use of title-case forms
-of initial characters (correctly producing for example Džungla instead
-of incorrect DŽungla).
-
-*** Characters which turn into multiple ones when cased are correctly handled.
-For example, fi ligature is converted to FI when upper cased.
-
-*** Greek small sigma is correctly handled when at the end of the word.
-Strings such as ΌΣΟΣ are now correctly converted to Όσος when
-capitalized instead of incorrect Όσοσ (compare lowercase sigma at the
-end of the word).
-
-+++
-** Emacs can now auto-save buffers to visited files in a more robust
-manner via the new mode 'auto-save-visited-mode'. Unlike
-'auto-save-visited-file-name', this mode uses the normal saving
-procedure and therefore obeys saving hooks.
-'auto-save-visited-file-name' is now obsolete.
-
-+++
-** New behavior of 'mark-defun'.
-Prefix argument selects that many (or that many more) defuns.
-Negative prefix arg flips the direction of selection. Also,
-'mark-defun' between defuns correctly selects N following defuns (or
--N previous for negative arguments). Finally, comments preceding the
-defun are selected unless they are separated from the defun by a blank
-line.
-
-** New command 'replace-buffer-contents'.
-This command replaces the contents of the accessible portion of the
-current buffer with the contents of the accessible portion of a
-different buffer while keeping point, mark, markers, and text
-properties as intact as possible.
-
-+++
-** New commands 'apropos-local-variable' and 'apropos-local-value.
-These are buffer-local versions of 'apropos-variable' and
-'apropos-value', respectively. They show buffer-local variables whose
-names and values, respectively, match a given pattern.
-
-+++
-** More user control of reordering bidirectional text for display.
-The two new variables, 'bidi-paragraph-start-re' and
-'bidi-paragraph-separate-re', allow customization of what exactly are
-paragraphs, for the purposes of bidirectional display.
+* Editing Changes in Emacs 27.1
+ ---
+ ** New variable 'x-wait-for-event-timeout'.
+ This controls how long Emacs will wait for updates to the graphical
+ state to take effect (making a frame visible, for example).
+
\f
-* Changes in Specialized Modes and Packages in Emacs 26.1
+* Changes in Specialized Modes and Packages in Emacs 27.1
----
-** New function `cl-generic-p'.
-
-** Dired
-
-+++
-*** You can answer 'all' in 'dired-do-delete' to delete recursively all
-remaining directories without more prompts.
-
-+++
-*** Dired supports wildcards in the directory part of the file names.
-
-+++
-*** You can now use '`?`' in 'dired-do-shell-command'.
-It gets replaced by the current file name, like ' ? '.
-
-+++
-*** A new option 'dired-always-read-filesystem' default to nil.
-If non-nil, buffers visiting files are reverted before search them;
-for instance, in 'dired-mark-files-containing-regexp' a non-nil value
-of this option means the file is revisited in a temporary buffer;
-this temporary buffer is the actual buffer searched: the original buffer
-visiting the file is not modified.
-
----
-*** Users can now customize mouse clicks in Dired in a more flexible way.
-The new command 'dired-mouse-find-file' can be bound to a mouse click
-and used to visit files/directories in Dired in the selected window.
-The new command 'dired-mouse-find-file-other-frame' similarly visits
-files/directories in another frame. You can write your own commands
-that invoke 'dired-mouse-find-file' with non-default optional
-arguments, to tailor the effects of mouse clicks on file names in
-Dired buffers.
-
-+++
-*** In wdired, when editing files to contain slash characters,
-the resulting directories are automatically created. Whether to do
-this is controlled by the 'wdired-create-parent-directories' variable.
-
-+++
-*** 'W' is now bound to 'browse-url-of-dired-file', and is useful for
-viewing HTML files and the like.
-
----
-*** New variable 'dired-clean-confirm-killing-deleted-buffers'
-controls whether Dired asks to kill buffers visiting deleted files and
-directories. The default is t, so Dired asks for confirmation, to
-keep previous behavior.
-
----
-** html2text is now marked obsolete.
-
----
-** smerge-refine-regions can refine regions in separate buffers
-
----
-** Info menu and index completion uses substring completion by default.
-This can be customized via the info-menu category in
-completion-category-override.
-
-+++
-** The ancestor buffer is shown by default in 3-way merges.
-A new option ediff-show-ancestor and a new toggle
-ediff-toggle-show-ancestor.
-
----
-** TeX: Add luatex and xetex as alternatives to pdftex
-
-** Electric-Buffer-menu
-
-+++
-*** Key 'U' is bound to 'Buffer-menu-unmark-all' and key 'M-DEL' is
-bound to 'Buffer-menu-unmark-all-buffers'.
-
-** bs
-
----
-*** Two new commands 'bs-unmark-all', bound to 'U', and
-'bs-unmark-previous', bound to <backspace>.
-
-** Buffer-menu
-
-+++
-*** Two new commands 'Buffer-menu-unmark-all', bound to 'U' and
-'Buffer-menu-unmark-all-buffers', bound to 'M-DEL'.
-
----
-** Checkdoc
-
-*** 'checkdoc-arguments-in-order-flag' now defaults to nil.
-
-** Gnus
+** Enhanced xterm support
----
-*** The .newsrc file will now only be saved if the native select
-method is an NNTP select method.
-
-+++
-*** A new command for sorting articles by readedness marks has been
-added: 'C-c C-s C-m C-m'.
-
-+++
-
-*** In message-citation-line-format the %Z format is now the time zone name
-instead of the numeric form. The %z format continues to be the
-numeric form. The new behavior is compatible with format-time-string.
-
-** Ibuffer
-
----
-*** New command 'ibuffer-jump'.
-
----
-*** New filter commands 'ibuffer-filter-by-basename',
-'ibuffer-filter-by-file-extension', 'ibuffer-filter-by-directory',
-'ibuffer-filter-by-starred-name', 'ibuffer-filter-by-modified'
-and 'ibuffer-filter-by-visiting-file'; bound respectively
-to '/b', '/.', '//', '/*', '/i' and '/v'.
-
----
-*** Two new commands 'ibuffer-filter-chosen-by-completion'
-and 'ibuffer-and-filter', the second bound to '/&'.
-
----
-*** The commands 'ibuffer-pop-filter', 'ibuffer-pop-filter-group',
-'ibuffer-or-filter' and 'ibuffer-filter-disable' have the alternative
-bindings '/<up>', '/S-<up>', '/|' and '/DEL', respectively.
-
----
-*** The data format specifying filters has been extended to allow
-explicit logical 'and', and a more flexible form for logical 'not'.
-See 'ibuffer-filtering-qualifiers' doc string for full details.
-
----
-*** A new command 'ibuffer-copy-buffername-as-kill'; bound
-to 'B'.
-
----
-*** New command 'ibuffer-change-marks'; bound to '* c'.
-
----
-*** A new command 'ibuffer-mark-by-locked' to mark
-all locked buffers; bound to '% L'.
-
----
-*** A new option 'ibuffer-locked-char' to indicate
-locked buffers; Ibuffer shows a new column displaying
-'ibuffer-locked-char' for locked buffers.
-
----
-*** A new command 'ibuffer-unmark-all-marks' to unmark
-all buffers without asking confirmation; bound to
-'U'; 'ibuffer-do-replace-regexp' bound to 'r'.
-
----
-*** A new command 'ibuffer-mark-by-content-regexp' to mark buffers
-whose content matches a regexp; bound to '% g'.
-
----
-*** Two new options 'ibuffer-never-search-content-name' and
-'ibuffer-never-search-content-mode' used by
-'ibuffer-mark-by-content-regexp'.
-
-** Browse-URL
-
----
-*** Support for opening links to man pages in Man or WoMan mode.
-
-** Comint
-
----
-*** New user option 'comint-move-point-for-matching-input' to control
-where to place point after C-c M-r and C-c M-s.
-
-** Compilation mode
-
----
-*** Messages from CMake are now recognized.
-
-+++
-*** The number of errors, warnings, and informational messages is now
-displayed in the mode line. These are updated as compilation
-proceeds.
-
-** Grep
-
----
-*** Grep commands will now use GNU grep's '--null' option if
-available, which allows distinguishing the filename from contents if
-they contain colons. This can be controlled by the new custom option
-'grep-use-null-filename-separator'.
-
----
-*** The grep/rgrep/lgrep functions will now ask about saving files
-before running. This is controlled by the 'grep-save-buffers'
-variable.
-
-** Edebug
-
----
-*** Edebug can be prevented from pausing 1 second after reaching a
-breakpoint (e.g. with "f" and "o") by customizing the new option
-'edebug-sit-on-break'.
-
-+++
-*** New customizable option 'edebug-max-depth'
-This allows to enlarge the maximum recursion depth when instrumenting
-code.
-
-** Eshell
-
----
-*** 'eshell-input-filter's value is now a named function
-'eshell-input-filter-default', and has a new custom option
-'eshell-input-filter-initial-space' to ignore adding commands prefixed
-with blank space to eshell history.
-
-** eww
-
-+++
-*** New 'M-RET' command for opening a link at point in a new eww buffer.
-
-+++
-*** A new 's' command for switching to another eww buffer via the minibuffer.
-
----
-*** The 'o' command ('shr-save-contents') has moved to 'O' to avoid collision
-with the 'o' command from 'image-map'.
-
-+++
-*** A new command 'C' ('eww-toggle-colors') can be used to toggle
-whether to use the HTML-specified colors or not. The user can also
-customize the 'shr-use-colors' variable.
-
----
-*** Images that are being loaded are now marked with gray
-"placeholder" images of the size specified by the HTML. They are then
-replaced by the real images asynchronously, which will also now
-respect width/height HTML specs (unless they specify widths/heights
-bigger than the current window).
-
----
-*** The 'w' command on links is now 'shr-maybe-probe-and-copy-url'.
-'shr-copy-url' now only copies the url at point; users who wish to
-avoid accidentally accessing remote links may rebind 'w' and 'u' in
-'eww-link-keymap' to it.
-
-
-** Ido
-
----
-*** The commands 'find-alternate-file-other-window',
-'dired-other-window', 'dired-other-frame', and
-'display-buffer-other-window' are now remapped to Ido equivalents if
-Ido mode is active.
-
-** Images
-
-+++
-*** Images are automatically scaled before displaying based on the
-'image-scaling-factor' variable (if Emacs supports scaling the images
-in question).
-
-+++
-*** It's now possible to specify aspect-ratio preserving combinations
-of :width/:max-height and :height/:max-width keywords. In either
-case, the "max" keywords win. (Previously some combinations would,
-depending on the aspect ratio of the image, just be ignored and in
-other instances this would lead to the aspect ratio not being
-preserved.)
-
-+++
-*** Images inserted with 'insert-image' and related functions get a
-keymap put into the text properties (or overlays) that span the
-image. This keymap binds keystrokes for manipulating size and
-rotation, as well as saving the image to a file. These commands are
-also available in 'image-mode'.
-
-+++
-*** A new library for creating and manipulating SVG images has been
-added. See the "SVG Images" section in the Lisp reference manual for
-details.
-
-+++
-*** New setf-able function to access and set image parameters is
-provided: 'image-property'.
-
----
-*** New commands 'image-scroll-left' and 'image-scroll-right'
-for 'image-mode' that complement 'image-scroll-up' and
-'image-scroll-down': they have the same prefix arg behavior and stop
-at image boundaries.
-
-** Image-Dired
-
----
-*** Now provides a minor mode 'image-dired-minor-mode' which replaces
-the function 'image-dired-setup-dired-keybindings'.
-
----
-*** Thumbnail generation is now asynchronous.
-The number of concurrent processes is limited by the variable
-'image-dired-thumb-job-limit'.
-
----
-*** 'image-dired-thumbnail-storage' has a new option 'standard-large'
-for generating 256x256 thumbnails according to the Thumbnail Managing
-Standard.
-
----
-*** Inherits movement keys from 'image-mode' for viewing full images.
-This includes the usual char, line, and page movement commands.
-
----
-*** All the -options types have been changed to argument lists
-instead of shell command strings. This change affects
-'image-dired-cmd-create-thumbnail-options',
-'image-dired-cmd-create-temp-image-options',
-'image-dired-cmd-rotate-thumbnail-options',
-'image-dired-cmd-rotate-original-options',
-'image-dired-cmd-write-exif-data-options',
-'image-dired-cmd-read-exif-data-options', and introduces
-'image-dired-cmd-pngnq-options', 'image-dired-cmd-pngcrush-options',
-'image-dired-cmd-create-standard-thumbnail-options'
-
----
-*** Recognizes more tools by default, including pngnq-s9 and OptiPNG
-
----
-*** 'find-file' and related commands now work on thumbnails and
-displayed images, providing a default argument of the original file name
-via an addition to 'file-name-at-point-functions'.
-
----
-** The default 'Info-default-directory-list' no longer checks some obsolete
-directory suffixes (gnu, gnu/lib, gnu/lib/emacs, emacs, lib, lib/emacs)
-when searching for info directories.
-
-+++
-** The commands that add ChangeLog entries now prefer a VCS root directory
-for the ChangeLog file, if none already exists. Customize
-'change-log-directory-files' to nil for the old behavior.
-
----
-** Support for non-string values of 'time-stamp-format' has been removed.
-
-** Message
-
----
-*** 'message-use-idna' now defaults to t (because Emacs comes with
-built-in IDNA support now).
-
----
-*** When sending HTML messages with embedded images, and you have
-exiftool installed, and you rotate images with EXIF data (i.e.,
-JPEGs), the rotational information will be inserted into the outgoing
-image in the message. (The original image will not have its
-orientation affected.)
-
----
-*** The 'message-valid-fqdn-regexp' variable has been removed, since
-there are now top-level domains added all the time. Message will no
-longer warn about sending emails to top-level domains it hasn't heard
-about.
-
-*** 'message-beginning-of-line' (bound to C-a) understands folded headers.
-In 'visual-line-mode' it will look for the true beginning of a header
-while in non-'visual-line-mode' it will move the point to the indented
-header's value.
-
-** Package
-
-+++
-*** The new variable 'package-gnupghome-dir' has been added to control
-where the GnuPG home directory (used for signature verification) is
-located and whether GnuPG's option "--homedir" is used or not.
-
----
-*** Deleting a package no longer respects 'delete-by-moving-to-trash'.
-
-** Tramp
-
-+++
-*** The method part of remote file names is mandatory now.
-A valid remote file name starts with "/method:host:" or
-"/method:user@host:".
-
-+++
-*** The new pseudo method "-" is a marker for the default method.
-"/-::" is the shortest remote file name then.
-
-+++
-*** The command 'tramp-change-syntax' allows to choose an alternative
-remote file name syntax.
-
-+++
-*** New connection method "sg", which supports editing files under a
-different group ID.
-
-+++
-*** New connection method "doas" for OpenBSD hosts.
-
-+++
-*** New connection method "gdrive", which allows to access Google
-Drive onsite repositories.
-
-+++
-*** Gateway methods in Tramp have been removed.
-Instead, the Tramp manual documents how to configure ssh and PuTTY
-accordingly.
-
-+++
-*** Setting the "ENV" environment variable in
-'tramp-remote-process-environment' enables reading of shell
-initialization files.
-
----
-*** Tramp is able now to send SIGINT to remote asynchronous processes.
-
----
-*** Variable 'tramp-completion-mode' is obsoleted.
-
----
-** 'auto-revert-use-notify' is set back to t in 'global-auto-revert-mode'.
-
-** JS mode
-
----
-*** JS mode now sets 'comment-multi-line' to t.
-
----
-*** New variable 'js-indent-align-list-continuation', when set to nil,
-will not align continuations of bracketed lists, but will indent them
-by the fixed width 'js-indent-level'.
-
-** CSS mode
-
----
-*** Support for completing attribute values, at-rules, bang-rules,
-HTML tags, classes and IDs using the 'completion-at-point' command.
-Completion candidates for HTML classes and IDs are retrieved from open
-HTML mode buffers.
-
----
-*** CSS mode now binds 'C-h S' to a function that will show
-information about a CSS construct (an at-rule, property, pseudo-class,
-pseudo-element, with the default being guessed from context). By
-default the information is looked up on the Mozilla Developer Network,
-but this can be customized using 'css-lookup-url-format'.
-
----
-*** CSS colors are fontified using the color they represent as the
-background. For instance, #ff0000 would be fontified with a red
-background.
-
-+++
-** Emacs now supports character name escape sequences in character and
-string literals. The syntax variants \N{character name} and
-\N{U+code} are supported.
-
-+++
-** Prog mode has some support for multi-mode indentation.
-This allows better indentation support in modes that support multiple
-programming languages in the same buffer, like literate programming
-environments or ANTLR programs with embedded Python code.
-
-A major mode can provide indentation context for a sub-mode through
-the 'prog-indentation-context' variable. To support this, modes that
-provide indentation should use 'prog-widen' instead of 'widen' and
-'prog-first-column' instead of a literal zero. See the node
-"Mode-Specific Indent" in the ELisp manual for more details.
-
-** ERC
-
----
-*** New variable 'erc-default-port-tls' used to connect to TLS IRC
-servers.
-
-** URL
-
-+++
-*** The new function 'url-cookie-delete-cookie' can be used to
-programmatically delete all cookies, or cookies from a specific
-domain.
-
-+++
-*** 'url-retrieve-synchronously' now takes an optional timeout parameter.
-
----
-*** The URL package now support HTTPS over proxies supporting CONNECT.
-
-+++
-*** 'url-user-agent' now defaults to 'default', and the User-Agent
-string is computed dynamically based on 'url-privacy-level'.
-
-** VC and related modes
-
----
-*** The VC state indicator in the mode line now defaults to more
-colorful faces to make it more obvious to the user what the state is.
-See the 'vc-faces' customization group.
-
-+++
-*** 'vc-dir-mode' now binds 'vc-log-outgoing' to 'O'; and has various
-branch-related commands on a keymap bound to 'B'.
-
-** CC mode
-
----
-*** Opening a .h file will turn C or C++ mode depending on language used.
-This is done with the help of 'c-or-c++-mode' function which analyses
-contents of the buffer to determine whether it's a C or C++ source
-file.
-
----
-** New DNS mode command 'dns-mode-ipv6-to-nibbles' to convert IPv6 addresses
-to a format suitable for reverse lookup zone files.
-
-** Ispell
-
-+++
-*** Enchant is now supported as a spell-checker.
-
-Enchant is a meta-spell-checker that uses providers
-such as Hunspell to do the actual checking. With it, users can use
-spell-checkers not directly supported by Emacs, such as Voikko, Hspell
-and AppleSpell, more easily share personal word-lists with other
-programs, and configure different spelling-checkers for different
-languages. (Version 2.1.0 or later of Enchant is required.)
-
-** Flymake
-
-+++
-*** Emacs no longer prompts the user before killing Flymake processes on exit.
+*** New variable 'xterm-set-window-title' controls whether Emacs
+sets the XTerm window title. The default is to set the window title.
\f
-* New Modes and Packages in Emacs 26.1
-
-** New Elisp data-structure library 'radix-tree'.
-
-** New library 'xdg' with utilities for some XDG standards and specs.
-
-** HTML
-
-+++
-*** A new submode of 'html-mode', 'mhtml-mode', is now the default
-mode for *.html files. This mode handles indentation,
-fontification, and commenting for embedded JavaScript and CSS.
-
-** New mode 'conf-toml-mode' is a sub-mode of conf-mode, specialized
- for editing TOML files.
-
-** New mode 'conf-desktop-mode' is a sub-mode of conf-unix-mode,
-specialized for editing freedesktop.org desktop entries.
-
-** New minor mode 'pixel-scroll-mode' provides smooth pixel-level scrolling.
-
-** New major mode 'less-css-mode' (a minor variant of 'css-mode') for
-editing Less files.
+* New Modes and Packages in Emacs 27.1
\f
-* Incompatible Lisp Changes in Emacs 26.1
-
----
-*** password-data is now a hash-table
-so that `password-read' can use any object for the `key' argument.
-
-+++
-*** Command 'dired-mark-extension' now automatically prepends a '.' to the
-extension when not present. The new command 'dired-mark-suffix' behaves
-similarly but it doesn't prepend a '.'.
-
-+++
-** Certain cond/pcase/cl-case forms are now compiled using a faster jump
-table implementation. This uses a new bytecode op 'switch', which
-isn't compatible with previous Emacs versions. This functionality can
-be disabled by setting 'byte-compile-cond-use-jump-table' to nil.
-
----
-** The alist 'ucs-names' is now a hash table.
-
----
-** 'if-let' and 'when-let' are subsumed by 'if-let*' and 'when-let*'.
-The incumbent 'if-let' and 'when-let' are now marked obsolete.
-'if-let*' and 'when-let*' do not accept the single tuple special case.
-New macro 'and-let*' is an implementation of the Scheme SRFI-2 syntax
-of the same name. 'if-let*' and 'when-let*' now accept the same
-binding syntax as 'and-let*'.
-
----
-** 'C-up', 'C-down', 'C-left' and 'C-right' are now defined in term
-mode to send the same escape sequences that xterm does. This makes
-things like forward-word in readline work.
-
----
-** hideshow mode got four key bindings that are analogous to outline
-mode bindings: 'C-c @ C-a', 'C-c @ C-t', 'C-c @ C-d', and 'C-c @ C-e.'
-
----
-** Customizable variable 'query-replace-from-to-separator'
-now doesn't propertize the string value of the separator.
-Instead, text properties are added by query-replace-read-from.
-Additionally, the new nil value restores pre-24.5 behavior
-of not providing replacement pairs via the history.
-
----
-** Some obsolete functions, variables, and faces have been removed:
-*** make-variable-frame-local. Variables cannot be frame-local any more.
-*** From subr.el: window-dot, set-window-dot, read-input, show-buffer,
-eval-current-buffer, string-to-int
-*** icomplete-prospects-length.
-*** All the default-FOO variables that hold the default value of the
-FOO variable. Use 'default-value' and 'setq-default' to access and
-change FOO, respectively. The exhaustive list of removed variables is:
-'default-mode-line-format', 'default-header-line-format',
-'default-line-spacing', 'default-abbrev-mode', 'default-ctl-arrow',
-'default-truncate-lines', 'default-left-margin', 'default-tab-width',
-'default-case-fold-search', 'default-left-margin-width',
-'default-right-margin-width', 'default-left-fringe-width',
-'default-right-fringe-width', 'default-fringes-outside-margins',
-'default-scroll-bar-width', 'default-vertical-scroll-bar',
-'default-indicate-empty-lines', 'default-indicate-buffer-boundaries',
-'default-fringe-indicator-alist', 'default-fringe-cursor-alist',
-'default-scroll-up-aggressively', 'default-scroll-down-aggressively',
-'default-fill-column', 'default-cursor-type',
-'default-cursor-in-non-selected-windows',
-'default-buffer-file-coding-system', 'default-major-mode', and
-'default-enable-multibyte-characters'.
-*** Many variables obsoleted in 22.1 referring to face symbols
-
-+++
-** The variable 'text-quoting-style' no longer affects the treatment
-of curved quotes in format arguments to functions like 'message' and
-'format-message'. In particular, when this variable's value is
-'grave', all quotes in formats are output as-is.
-
----
-** Functions like 'check-declare-file' and 'check-declare-directory'
-now generate less chatter and more-compact diagnostics. The auxiliary
-function 'check-declare-errmsg' has been removed.
-
-+++
-** The regular expression character class [:blank:] now matches
-Unicode horizontal whitespace as defined in the Unicode Technical
-Standard #18. If you only want to match space and tab, use [ \t]
-instead.
-
-+++
-** 'min' and 'max' no longer round their results.
-Formerly, they returned a floating-point value if any argument was
-floating-point, which was sometimes numerically incorrect. For
-example, on a 64-bit host (max 1e16 10000000000000001) now returns its
-second argument instead of its first.
-
-+++
-** The variable 'old-style-backquotes' has been made internal and
-renamed to 'lread--old-style-backquotes'. No user code should use
-this variable.
-
----
-** To avoid confusion caused by "smart quotes", the reader no longer
-accepts Lisp symbols which begin with the following quotation
-characters: ‘’‛“”‟〞＂＇, unless they are escaped with backslash.
-
-+++
-** 'default-file-name-coding-system' now defaults to a coding system
-that does not process CRLF. For example, it defaults to utf-8-unix
-instead of to utf-8. Before this change, Emacs would sometimes
-mishandle file names containing these control characters.
+* Incompatible Lisp Changes in Emacs 27.1
-+++
-** 'file-attributes', 'file-symlink-p' and 'make-symbolic-link' no
-longer quietly mutate the target of a local symbolic link, so that
-Emacs can access and copy them reliably regardless of their contents.
-The following changes are involved.
-
----
-*** 'file-attributes' and 'file-symlink-p' no longer prepend "/:" to
-symbolic links whose targets begin with "/" and contain ":". For
-example, if a symbolic link "x" has a target "/y:z:", '(file-symlink-p
-"x")' now returns "/y:z:" rather than "/:/y:z:".
-
----
-*** 'make-symbolic-link' no longer looks for file name handlers of
-target when creating a symbolic link. For example,
-'(make-symbolic-link "/y:z:" "x")' now creates a symbolic link to
-"/y:z:" instead of failing.
-
-+++
-*** 'make-symbolic-link' removes the remote part of a link target if
-target and newname have the same remote part. For example,
-'(make-symbolic-link "/x:y:a" "/x:y:b")' creates a link with the
-literal string "a"; and '(make-symbolic-link "/x:y:a" "/x:z:b")'
-creates a link with the literal string "/x:y:a" instead of failing.
-
-+++
-*** 'make-symbolic-link' now expands a link target with leading "~"
-only when the optional third arg is an integer, as when invoked
-interactively. For example, '(make-symbolic-link "~y" "x")' now
-creates a link with target the literal string "~y"; to get the old
-behavior, use '(make-symbolic-link (expand-file-name "~y") "x")'. To
-avoid this expansion in interactive use, you can now prefix the link
-target with "/:". For example, '(make-symbolic-link "/:~y" "x" 1)'
-now creates a link to literal "~y".
-
-+++
-** 'file-truename' returns a quoted file name if the target of a
-symbolic link has remote file name syntax.
-
-+++
-** Module functions are now implemented slightly differently; in
-particular, the function 'internal--module-call' has been removed.
-Code that depends on undocumented internals of the module system might
-break.
-
----
-** The argument LOCKNAME of 'write-region' is propagated to file name
-handlers now.
-
----
-** When built against recent versions of GTK+, Emacs always uses
-gtk_window_move for moving frames and ignores the value of the
-variable 'x-gtk-use-window-move'. The variable is now obsolete.
-
-+++
-** Several functions that create or rename files now treat their
-destination argument specially only when it is a directory name, i.e.,
-when it ends in '/' on GNU and other POSIX-like systems. When the
-destination argument D of one of these functions is an existing
-directory and the intent is to act on an entry in that directory, D
-should now be a directory name. For example, (rename-file "e" "f/")
-renames to 'f/e'. Although this formerly happened sometimes even when
-D was not a directory name, as in (rename-file "e" "f") where 'f'
-happened to be a directory, the old behavior often contradicted the
-documentation and had inherent races that led to security holes. A
-call like (rename-file C D) that used the old, undocumented behavior
-can be written as (rename-file C (file-name-as-directory D)), a
-formulation portable to both older and newer versions of Emacs.
-Affected functions include add-name-to-file, copy-directory,
-copy-file, format-write-file, gnus-copy-file, make-symbolic-link,
-rename-file, thumbs-rename-images, and write-file.
-
----
-** The list returned by 'overlays-at' is now in decreasing priority order.
-The documentation of this function always said the order should be
-that of decreasing priority, if the 2nd argument of the function is
-non-nil, but the code returned the list in the increasing order of
-priority instead. Now the code does what the documentation says it
-should do.
+** The FILENAME argument to 'file-name-base' is now mandatory and no
+longer defaults to 'buffer-file-name'.
---
- ** 'eldoc-message' only accepts one argument now. Programs that
- called it with multiple arguments before should pass them through
- 'format' first. Even that is discouraged: for ElDoc support, you
- should set 'eldoc-documentation-function' instead of calling
- 'eldoc-message' directly.
+ ** The function 'eldoc-message' now accepts a single argument.
+ Programs that called it with multiple arguments before should pass
+ them through 'format' first. Even that is discouraged: for ElDoc
+ support, you should set 'eldoc-documentation-function' instead of
+ calling 'eldoc-message' directly.
\f
-* Lisp Changes in Emacs 26.1
-
-+++
-** The function 'assoc' now takes an optional third argument TESTFN.
-This argument, when non-nil, is used for comparison instead of
-'equal'.
-
-+++
-** New optional argument TESTFN in 'alist-get', 'map-elt' and 'map-put'.
-If non-nil, the argument specifies a function to use for comparison,
-instead of, respectively, 'assq' and 'eql'.
-
-+++
-** New function 'seq-set-equal-p' to check if SEQUENCE1 and SEQUENCE2
-contain the same elements, regardless of the order.
-
-+++
-** The new function 'mapbacktrace' applies a function to all frames of
-the current stack trace.
-
-+++
-** The new function 'file-name-case-insensitive-p' tests whether a
-given file is on a case-insensitive filesystem.
-
-+++
-** Several accessors for the value returned by 'file-attributes'
-have been added. They are: 'file-attribute-type',
-'file-attribute-link-number', 'file-attribute-user-id',
-'file-attribute-group-id', 'file-attribute-access-time',
-'file-attribute-modification-time',
-'file-attribute-status-change-time', 'file-attribute-size',
-'file-attribute-modes', 'file-attribute-inode-number',
-'file-attribute-device-number' and 'file-attribute-collect'.
-
-+++
-** The new function 'buffer-hash' computes a fast, non-consing hash of
-a buffer's contents.
-
-+++
-** 'interrupt-process' now consults the list 'interrupt-process-functions',
-to determine which function has to be called in order to deliver the
-SIGINT signal. This allows Tramp to send the SIGINT signal to remote
-asynchronous processes. The hitherto existing implementation has been
-moved to 'internal-default-interrupt-process'.
-
-+++
-** The new function 'read-multiple-choice' prompts for multiple-choice
-questions, with a handy way to display help texts.
-
----
-** 'comment-indent-function' values may now return a cons to specify a
-range of indentation.
-
-+++
-** New optional argument TEXT in 'make-temp-file'.
-
----
-** New function `define-symbol-prop'.
-
-** Checksum/Hash
-
-+++
-** New function 'secure-hash-algorithms' to list the algorithms that
-'secure-hash' supports.
-See the node "(elisp) Checksum/Hash" in the ELisp manual for details.
-
-+++
-** Emacs now exposes the GnuTLS cryptographic API with the functions
-'gnutls-macs' and 'gnutls-hash-mac'; 'gnutls-digests' and
-'gnutls-hash-digest'; 'gnutls-ciphers' and 'gnutls-symmetric-encrypt'
-and 'gnutls-symmetric-decrypt'.
-See the node "(elisp) GnuTLS Cryptography" in the ELisp manual for details.
-
-+++
-** Emacs now supports records for user-defined types, via the new
-functions 'make-record', 'record', and 'recordp'. Records are now
-used internally to represent cl-defstruct and defclass instances, for
-example.
-
-+++
-** 'save-some-buffers' now uses 'save-some-buffers-default-predicate'
-to decide which buffers to ask about, if the PRED argument is nil.
-The default value of 'save-some-buffers-default-predicate' is nil,
-which means ask about all file-visiting buffers.
-
----
-** string-(to|as|make)-(uni|multi)byte are now declared obsolete.
-
-+++
-** New variable 'while-no-input-ignore-events' which allow
-setting which special events 'while-no-input' should ignore.
-It is a list of symbols.
-
----
-** New function 'undo-amalgamate-change-group' to get rid of
-undo-boundaries between two states.
-
----
-** New var 'definition-prefixes' is a hash table mapping prefixes to
-the files where corresponding definitions can be found. This can be
-used to fetch definitions that are not yet loaded, for example for
-'C-h f'.
-
----
-** New var 'syntax-ppss-table' to control the syntax-table used in
-'syntax-ppss'.
-
-+++
-** 'define-derived-mode' can now specify an :after-hook form, which
-gets evaluated after the new mode's hook has run. This can be used to
-incorporate configuration changes made in the mode hook into the
-mode's setup.
-
----
-** Autoload files can be generated without timestamps,
-by setting 'autoload-timestamps' to nil.
-FIXME As an experiment, nil is the current default.
-If no insurmountable problems before next release, it can stay that way.
-
----
-** 'gnutls-boot' now takes a parameter ':complete-negotiation' that
-says that negotiation should complete even on non-blocking sockets.
-
----
-** There is now a new variable 'flyspell-sort-corrections-function'
-that allows changing the way corrections are sorted.
-
----
-** The new command 'fortune-message' has been added, which displays
-fortunes in the echo area.
-
-+++
-** New function 'func-arity' returns information about the argument list
-of an arbitrary function. This generalizes 'subr-arity' for functions
-that are not built-in primitives. We recommend using this new
-function instead of 'subr-arity'.
-
----
-** New function 'region-bounds' can be used in the interactive spec
-to provide region boundaries (for rectangular regions more than one)
-to an interactively callable function as a single argument instead of
-two separate arguments region-beginning and region-end.
-
-+++
-** 'parse-partial-sexp' state has a new element. Element 10 is
-non-nil when the last character scanned might be the first character
-of a two character construct, i.e., a comment delimiter or escaped
-character. Its value is the syntax of that last character.
-
-+++
-** 'parse-partial-sexp's state, element 9, has now been confirmed as
-permanent and documented, and may be used by Lisp programs. Its value
-is a list of currently open parenthesis positions, starting with the
-outermost parenthesis.
-
----
-** 'read-color' will now display the color names using the color itself
-as the background color.
-
----
-** The function 'redirect-debugging-output' now works on platforms
-other than GNU/Linux.
-
-+++
-** The new function 'string-version-lessp' compares strings by
-interpreting consecutive runs of numerical characters as numbers, and
-compares their numerical values. According to this predicate,
-"foo2.png" is smaller than "foo12.png".
-
----
-** Numeric comparisons and 'logb' no longer return incorrect answers
-due to internal rounding errors. For example, (< most-positive-fixnum
-(+ 1.0 most-positive-fixnum)) now correctly returns t on 64-bit hosts.
-
----
-** The functions 'ffloor', 'fceiling', 'ftruncate' and 'fround' now
-accept only floating-point arguments, as per their documentation.
-Formerly, they quietly accepted integer arguments and sometimes
-returned nonsensical answers, e.g., (< N (ffloor N)) could return t.
-
----
-** On hosts like GNU/Linux x86-64 where a 'long double' fraction
-contains at least EMACS_INT_WIDTH - 3 bits, 'format' no longer returns
-incorrect answers due to internal rounding errors when formatting
-Emacs integers with %e, %f, or %g conversions. For example, on these
-hosts (eql N (string-to-number (format "%.0f" N))) now returns t for
-all Emacs integers N.
-
----
-** Calls that accept floating-point integers (for use on hosts with
-limited integer range) now signal an error if arguments are not
-integral. For example (decode-char 'ascii 0.5) now signals an error.
-
-+++
-** The new function 'char-from-name' converts a Unicode name string
-to the corresponding character code.
-
-+++
-** New functions 'sxhash-eq' and 'sxhash-eql' return hash codes of a
-Lisp object suitable for use with 'eq' and 'eql' correspondingly. If
-two objects are 'eq' ('eql'), then the result of 'sxhash-eq'
-('sxhash-eql') on them will be the same.
-
-+++
-** Function 'sxhash' has been renamed to 'sxhash-equal' for
-consistency with the new functions. For compatibility, 'sxhash'
-remains as an alias to 'sxhash-equal'.
-
-+++
-** 'make-hash-table' now defaults to a rehash threshold of 0.8125
-instead of 0.8, to avoid rounding glitches.
-
-+++
-** New function 'add-variable-watcher' can be used to call a function
-when a symbol's value is changed. This is used to implement the new
-debugger command 'debug-on-variable-change'.
-
-+++
-** Time conversion functions that accept a time zone rule argument now
-allow it to be OFFSET or a list (OFFSET ABBR), where the integer
-OFFSET is a count of seconds east of Universal Time, and the string
-ABBR is a time zone abbreviation. The affected functions are
-'current-time-string', 'current-time-zone', 'decode-time',
-'format-time-string', and 'set-time-zone-rule'.
-
-+++
-** 'format-time-string' now formats "%q" to the calendar quarter.
-
-+++
-** New built-in function 'mapcan'.
-It avoids unnecessary consing (and garbage collection).
-
-+++
-** 'car' and 'cdr' compositions 'cXXXr' and 'cXXXXr' are now part of Elisp.
-
-+++
-** 'gensym' is now part of Elisp.
-
----
-** Low-level list functions like 'length' and 'member' now do a better
-job of signaling list cycles instead of looping indefinitely.
-
-+++
-** The new functions 'make-nearby-temp-file' and 'temporary-file-directory'
-can be used for creation of temporary files of remote or mounted directories.
-
-+++
-** On GNU platforms when operating on a local file, 'file-attributes'
-no longer suffers from a race when called while another process is
-altering the filesystem. On non-GNU platforms 'file-attributes'
-attempts to detect the race, and returns nil if it does so.
-
-+++
-** The new function 'file-local-name' can be used to specify arguments
-of remote processes.
-
-+++
-** The new functions 'file-name-quote', 'file-name-unquote' and
-'file-name-quoted-p' can be used to quote / unquote file names with
-the prefix "/:".
-
-+++
-** The new error 'file-missing', a subcategory of 'file-error', is now
-signaled instead of 'file-error' if a file operation acts on a file
-that does not exist.
-
-+++
-** The function 'delete-directory' no longer signals an error when
-operating recursively and when some other process deletes the directory
-or its files before 'delete-directory' gets to them.
-
-+++
-*** New error type 'user-search-failed' like 'search-failed' but
-avoids debugger like 'user-error'.
-
-+++
-** The function 'line-number-at-pos' now takes a second optional
-argument 'absolute'. If this parameter is nil, the default, this
-function keeps on returning the line number taking potential narrowing
-into account. If this parameter is non-nil, the function ignores
-narrowing and returns the absolute line number.
-
----
-** The function 'color-distance' now takes a second optional argument
-'metric'. When non-nil, it should be a function of two arguments that
-accepts two colors and returns a number.
-
-** Changes in Frame and Window Handling
-
-+++
-*** Resizing a frame no longer runs 'window-configuration-change-hook'.
-'window-size-change-functions' should be used instead.
-
-+++
-*** The new function 'frame-size-changed-p' can tell whether a frame has
-been resized since the last time 'window-size-change-functions' has been
-run.
-
-+++
-*** The function 'frame-geometry' now also returns the width of a
-frame's outer border.
-
-+++
-*** New frame parameters and changed semantics for older ones
-
-+++
-**** 'z-group' positions a frame above or below all others.
-
-+++
-**** 'min-width' and 'min-height' specify the absolute minimum size of a
-frame.
-
-+++
-**** 'parent-frame' makes a frame the child frame of another Emacs
-frame. The section "Child Frames" in the Elisp manual describes the
-intrinsics of that relationship.
-
-+++
-**** 'delete-before' triggers deletion of one frame before that of
-another.
-
-+++
-**** 'mouse-wheel-frame' specifies another frame whose windows shall be
-scrolled instead.
-
-+++
-**** 'no-other-frame' has 'next-frame' and 'previous-frame' skip this
-frame.
-
-+++
-**** 'skip-taskbar' removes a frame's icon from the taskbar and has
-Alt-<TAB> skip this frame.
-
-+++
-**** 'no-focus-on-map' avoids that a frame gets input focus when mapped.
-
-+++
-**** 'no-accept-focus' means that a frame does not want to get input
-focus via the mouse.
-
-+++
-**** 'undecorated' removes the window manager decorations from a frame.
-
-+++
-**** 'override-redirect' tells the window manager to disregard this
-frame.
-
-+++
-**** 'width' and 'height' allow to specify pixel values and ratios now.
-
-+++
-**** 'left' and 'top' allow to specify ratios now.
-
-+++
-**** 'keep-ratio' preserves size and position of child frames when their
-parent frame is resized.
-
-+++
-**** 'no-special-glyphs' suppresses display of truncation and
-continuation glyphs in a frame.
-
-+++
-**** 'auto-hide-function' and 'minibuffer-exit' handle auto hiding of
-frames and exiting from minibuffer individually.
-
-+++
-**** 'fit-frame-to-buffer-margins' and 'fit-frame-to-buffer-sizes'
-handle fitting a frame to its buffer individually.
-
-+++
-**** 'drag-internal-border', 'drag-with-header-line',
-'drag-with-mode-line', 'snap-width', 'top-visible' and 'bottom-visible'
-allow to drag and resize frames with the mouse.
-
-*** The new function 'frame-list-z-order' returns a list of all frames
-in Z (stacking) order.
-
-+++
-*** The function 'x-focus-frame' optionally tries to not activate its
-frame.
-
-+++
-*** The variable 'focus-follows-mouse' has a third meaningful value
-'auto-raise' to indicate that the window manager automatically raises a
-frame when the mouse pointer enters it.
-
-+++
-*** The new function 'frame-restack' puts a frame above or below
-another on the display.
-
-+++
-*** The new face 'internal-border' specifies the background of a frame's
-internal border.
-
-+++
-*** The NORECORD argument of 'select-window' now has a meaningful value
-'mark-for-redisplay' which is like any other non-nil value but marks
-WINDOW for redisplay.
-
-+++
-*** Support for side windows is now official.
-The display action function 'display-buffer-in-side-window' will
-display its buffer in a side window. Functions for toggling all side
-windows on a frame, changing and reversing the layout of side windows
-and returning the main (major non-side) window of a frame are
-provided. For details consult the section "Side Windows" in the Elisp
-manual.
-
-+++
-*** Support for atomic windows - rectangular compositions of windows
-treated by 'split-window', 'delete-window' and 'delete-other-windows'
-like a single live window - is now official. For details consult the
-section "Atomic Windows" in the Elisp manual.
-
-+++
-*** New 'display-buffer' alist entry 'window-parameters' allows to
-assign window parameters to the window used for displaying the buffer.
-
-+++
-*** New function 'display-buffer-reuse-mode-window' is an action function
-suitable for use in 'display-buffer-alist'. For example, to avoid
-creating a new window when opening man pages when there's already one,
-use
-
-(add-to-list 'display-buffer-alist
- '("\\`\\*Man .*\\*\\'" .
- (display-buffer-reuse-mode-window
- (inhibit-same-window . nil)
- (mode . Man-mode))))
-
-+++
-*** New window parameter 'no-delete-other-windows' prevents that
-its window gets deleted by 'delete-other-windows'.
-
-+++
-*** New window parameters 'mode-line-format' and 'header-line-format'
-allow to override the buffer-local formats for this window.
-
-+++
-*** New command 'window-swap-states' swaps the states of two live
-windows.
-
-+++
-*** New functions 'window-pixel-width-before-size-change' and
-'window-pixel-height-before-size-change' support detecting which
-window changed size when 'window-size-change-functions' are run.
-
-+++
-*** The new function 'window-lines-pixel-dimensions' returns the pixel
-dimensions of a window's text lines.
-
-+++
-*** The new function 'window-largest-empty-rectangle' returns the
-dimensions of the largest rectangular area not occupying any text in a
-window's body.
-
-+++
-*** The semantics of 'mouse-autoselect-window' has changed slightly.
-For details see the section "Mouse Window Auto-selection" in the Elisp
-manual.
-
----
-** 'tcl-auto-fill-mode' is now declared obsolete. Its functionality
-can be replicated simply by setting 'comment-auto-fill-only-comments'.
-
-** New pcase pattern 'rx' to match against a rx-style regular expression.
-For details, see the doc string of 'rx--pcase-macroexpander'.
-
----
-** New functions to set region from secondary selection and vice versa.
-The new functions 'secondary-selection-to-region' and
-'secondary-selection-from-region' let you set the beginning and the
-end of the region from those of the secondary selection and vise
-versa.
+* Lisp Changes in Emacs 27.1
\f
-* Changes in Emacs 26.1 on Non-Free Operating Systems
-
-+++
-** Intercepting hotkeys on Windows 7 and later now works better.
-The new keyboard hooking code properly grabs system hotkeys such as
-Win-* and Alt-TAB, in a way that Emacs can get at them before the
-system. This makes the 'w32-register-hot-key' functionality work
-again on all versions of MS-Windows starting with Windows 7. On
-Windows NT and later you can now register any hotkey combination. (On
-Windows 9X, the previous limitations, spelled out in the Emacs manual,
-still apply.)
-
----
-** 'convert-standard-filename' no longer mirrors slashes on MS-Windows.
-Previously, on MS-Windows this function converted slash characters in
-file names into backslashes. It no longer does that. If your Lisp
-program used 'convert-standard-filename' to prepare file names to be
-passed to subprocesses (which is not the recommended usage of that
-function), you will now have to mirror slashes in your application
-code. One possible way is this:
-
- (let ((start 0))
- (while (string-match "/" file-name start)
- (aset file-name (match-beginning 0) ?\\)
- (setq start (match-end 0))))
-
----
-** GUI sessions on MS-Windows now treat SIGINT like Posix platforms do.
-The effect of delivering a Ctrl-C (SIGINT) signal to a GUI Emacs on
-MS-Windows is now the same as on Posix platforms -- Emacs saves the
-session and exits. In particular, this will happen if you start
-emacs.exe from the Windows shell, then type Ctrl-C into that shell's
-window.
-
----
-** 'signal-process' supports SIGTRAP on Windows XP and later.
-The 'kill' emulation on Windows now maps SIGTRAP to a call to the
-'DebugBreakProcess' API. This causes the receiving process to break
-execution and return control to the debugger. If no debugger is
-attached to the receiving process, the call is typically ignored.
-This is in contrast to the default action on POSIX Systems, where it
-causes the receiving process to terminate with a core dump if no
-debugger has been attached to it.
-
----
-** 'set-mouse-position' and 'set-mouse-absolute-pixel-position' work
-on macOS.
-
----
-** Emacs can now be run as a GUI application from the command line on
-macOS.
-
-+++
-** 'ns-appearance' and 'ns-transparent-titlebar' change the appearance
-of frame decorations on macOS 10.9+.
-
----
-** 'ns-use-thin-smoothing' enables thin font smoothing on macOS 10.8+.
-
----
-** 'process-attributes' on Darwin systems now returns more information.
-
----
-** Mousewheel and trackpad scrolling on macOS 10.7+ now behaves more
-like the macOS default. The new variables 'ns-mwheel-line-height',
-'ns-use-mwheel-acceleration' and 'ns-use-mwheel-momentum' can be used
-to customize the behavior.
+* Changes in Emacs 27.1 on Non-Free Operating Systems
\f
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projects / emacs.git / commitdiff