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diff --git a/etc/NEWS.27 b/etc/NEWS.27 new file mode 100644 index 00000000000..380ac71260d --- /dev/null +++ b/etc/NEWS.27 @@ -0,0 +1,3693 @@ +GNU Emacs NEWS -- history of user-visible changes. + +Copyright (C) 2017-2020 Free Software Foundation, Inc. +See the end of the file for license conditions. + +Please send Emacs bug reports to 'bug-gnu-emacs@gnu.org'. +If possible, use 'M-x report-emacs-bug'. + +This file is about changes in Emacs version 27. + +See file HISTORY for a list of GNU Emacs versions and release dates. +See files NEWS.26, NEWS.25, ..., NEWS.18, and NEWS.1-17 for changes +in older Emacs versions. + +You can narrow news to a specific version by calling 'view-emacs-news' +with a prefix argument or by typing 'C-u C-h C-n'. + +Temporary note: ++++ indicates that all relevant manuals in doc/ have been updated. +--- means no change in the manuals is needed. +When you add a new item, use the appropriate mark if you are sure it +applies, and please also update docstrings as needed. + + +* Installation Changes in Emacs 27.1 + +--- +** Emacs now uses GMP, the GNU Multiple Precision library. +By default, if 'configure' does not find a suitable libgmp, it +arranges for the included mini-gmp library to be built and used. +The new 'configure' option '--without-libgmp' uses mini-gmp even if a +suitable libgmp is available. + +--- +** Emacs can now use HarfBuzz as its shaping engine. +The new configure option '--with-harfbuzz' adds support for the +HarfBuzz text shaping engine. It is on by default; use './configure +--without-harfbuzz' to build without it. The HarfBuzz text shaping is +available via new font backend drivers 'xfthb' and 'ftcrhb' for Xft +and Cairo drawings, respectively, and via the 'harfbuzz' backend on +MS-Windows. The HarfBuzz text shaping is preferred to the previously +supported ones, so the font backends that use older shaping engines +(FLT on GNU and Unix systems and Uniscribe on MS-Windows) are not +enabled by default; they can be enabled via the 'font-backend' frame +parameter or via X resources. + +--- +** The new configure option '--with-json' adds native support for JSON. +This uses the Jansson library. The option is on by default; use +'./configure --with-json=no' to build without Jansson support. The +new JSON functions 'json-serialize', 'json-insert', +'json-parse-string', and 'json-parse-buffer' are typically much faster +than their Lisp counterparts from json.el. + +--- +** The configure option '--with-cairo' is no longer experimental. +This builds Emacs with Cairo drawing, and supports built-in printing +when Emacs is built with GTK+. Some severe bugs in this build were +fixed, and we can therefore offer this to users without caveats. Note +that building with Cairo enabled results in using Pango instead of +libXft for font support, and that Pango 1.44 has removed support for +bitmapped fonts. + ++++ +** Emacs now uses a "portable dumper" instead of unexec. +This improves compatibility with memory allocation on modern systems, +and in particular better supports the Address Space Layout +Randomization (ASLR) feature, a security technique used by most modern +operating systems. + +When built with the portable dumping support (which is the default), +Emacs looks for the "emacs.pdmp" file, generated during the build, in +its data directory at startup, and loads the dumped state from there. +The new command-line argument '--dump-file=FILE' allows specifying a +non-default ".pdmp" file to load the state from; see the node +"(emacs) Initial Options" in the Emacs manual for more information. + +An Emacs started via a dump file can create a new dump file only if it +was invoked with the '-batch' option. (This is a temporary +limitation; we plan on lifting it in a future release.) + +Although the portable dumper has been tested, it may have a bug on +unusual platforms. If you require traditional unexec dumping you can +use the configure-time option '--with-dumping=unexec'; however, please +file a bug report describing the situation, as unexec dumping is +deprecated, and we plan on removing it in some future release. + +--- +** The new configure option '--enable-checking=structs' attempts to +check that the portable dumper code has been updated to match the last +change to one of the data structures that it relies on. + +--- +** The configure options '--enable-checking=conslist' and +'--enable-checking=xmallocoverrun' have been withdrawn. The former +made Emacs irredeemably slow, and the latter made it crash. Neither +option was useful with modern debugging tools such as AddressSanitizer. +(See "etc/DEBUG" for the details of using the modern replacements of the +removed configure options.) + +--- +** Emacs no longer defaults to using ImageMagick to display images. +This is due to security and stability concerns with ImageMagick. To +override the default, use 'configure --with-imagemagick'. + +--- +** Several configure options now accept an option-argument 'ifavailable'. +For example, './configure --with-xpm=ifavailable' now configures Emacs +to attempt to use libxpm but to continue building even if libxpm is +absent. The other affected options are '--with-gif', '--with-gnutls', +'--with-jpeg', '--with-png', and '--with-tiff'. + +--- +** The 'etags' program now uses the C library's regular expression matcher. +If it's possible, 'etags' will use the regexp matcher from the +system's standard C library, otherwise it will be linked with a +compatible regex substitute. This lets developers maintain Emacs's +own regex code without having to also support other programs. The new +configure option '--without-included-regex' forces 'etags' to use the C +library's regex matcher even if the regex substitute ordinarily would +be used to work around compatibility problems. + +--- +** Emacs has been ported to the '-fcheck-pointer-bounds' option of GCC. +This causes Emacs to check bounds of some arrays addressed by its +internal pointers, which can be helpful when debugging the Emacs +interpreter or modules that it uses. If your platform supports it you +can enable it when configuring, e.g., './configure CFLAGS="-g3 -O2 +-mmpx -fcheck-pointer-bounds"' on Intel MPX platforms. + +--- +** Emacs now normally uses a C pointer type instead of a C integer +type to implement Lisp_Object, which is the fundamental machine word +type internal to the Emacs Lisp interpreter. This change aims to +catch typos and supports '-fcheck-pointer-bounds'. The 'configure' +option '--enable-check-lisp-object-type' is therefore no longer as +useful and so is no longer enabled by default in developer builds, +to reduce differences between developer and production builds. + +--- +** The distribution tarball now has test cases; 'make check' runs them. +This is intended mostly to help developers. + +--- +** Emacs now requires GTK 2.24 and GTK 3.10 for the GTK 2 and GTK 3 +builds respectively. + +--- +** New make target 'help' shows a summary of common make targets. + +--- +** Emacs now builds with dynamic module support by default. +Pass '--without-modules' to 'configure' to disable dynamic module +support. + +--- +** The ftx font backend driver is now obsolete and will be removed in +Emacs 28. + + +* Startup Changes in Emacs 27.1 + ++++ +** Emacs can now use the XDG convention for init files. +The 'XDG_CONFIG_HOME' environment variable (which defaults to +"~/.config") specifies the XDG configuration parent directory. Emacs +checks for "init.el" and other configuration files inside the "emacs" +subdirectory of 'XDG_CONFIG_HOME', i.e. "$XDG_CONFIG_HOME/emacs/init.el" + +However, Emacs will still initially look for init files in their +traditional locations if "~/.emacs.d" or "~/.emacs" exist, even if +"$XDG_CONFIG_HOME/emacs" also exists. This means that you must delete +or rename any existing "~/.emacs.d" and "~/.emacs" to enable use of +the XDG directory. + +If "~/.emacs.d" does not exist, and Emacs has decided to use it +(i.e. "$XDG_CONFIG_HOME/emacs" does not exist), Emacs will create it. +Emacs will never create "$XDG_CONFIG_HOME/emacs". + +Whichever directory Emacs decides to use, it will set +'user-emacs-directory' to point to it. + ++++ +** Emacs can now be configured using an early init file. +The file is called "early-init.el", in 'user-emacs-directory'. It is +loaded very early in the startup process: before graphical elements +such as the tool bar are initialized, and before the package manager +is initialized. The primary purpose is to allow customizing how the +package system is initialized given that initialization now happens +before loading the regular init file (see below). + +We recommend against putting any customizations in this file that +don't need to be set up before initializing installed add-on packages, +because the early init file is read too early into the startup +process, and some important parts of the Emacs session, such as +'window-system' and other GUI features, are not yet set up, which could +make some customization fail to work. + ++++ +** Installed packages are now activated *before* loading the init file. +As a result of this change, it is no longer necessary to call +'package-initialize' in your init file. + +Previously, a call to 'package-initialize' was automatically inserted +into the init file when Emacs was started. This call can now safely +be removed. Alternatively, if you want to ensure that your init file +is still compatible with earlier versions of Emacs, change it to: + +(when (< emacs-major-version 27) + (package-initialize)) + +However, if your init file changes the values of 'package-load-list' +or 'package-user-dir', or sets 'package-enable-at-startup' to nil then +it won't work right without some adjustment: +- You can move that code to the early init file (see above), so those + settings apply before Emacs tries to activate the packages. +- You can use the new 'package-quickstart' so activation of packages + does not need to pay attention to 'package-load-list' or + 'package-user-dir' any more. + +--- +** Emacs now notifies systemd when startup finishes or shutdown begins. +Units that are ordered after 'emacs.service' will only be started +after Emacs has finished initialization and is ready for use. +(If your Emacs is installed in a non-standard location and you copied the +emacs.service file to e.g. "~/.config/systemd/user/", you will need to copy +the new version of the file again.) + + +* Changes in Emacs 27.1 + ++++ +** Emacs now supports resizing and rotating images without ImageMagick. +All modern systems support this feature. (On GNU and Unix systems, +Cairo drawing or the XRender extension to X11 is required for this to +be available; the configure script will test for it and, if found, +enable scaling.) + +The new function 'image-transforms-p' can be used to test whether any +given frame supports these capabilities. + ++++ +** The Network Security Manager now allows more fine-grained control +of what checks to run via the 'network-security-protocol-checks' +user option. + ++++ +** TLS connections have their security tightened by default. +Most of the checks for outdated, believed-to-be-weak TLS algorithms +and ciphers are now switched on by default. (In addition, several new +TLS weaknesses are now warned about.) By default, the NSM will +flag connections using these weak algorithms and ask users whether to +allow them. To get the old behavior back (where certificates are +checked for validity, but no warnings about weak cryptography are +issued), you can either set 'network-security-protocol-checks' to nil, +or adjust the elements in that user option to only happen on the 'high' +security level (assuming you use the 'medium' level). + +--- +** New user option 'nsm-trust-local-network'. +Allows skipping Network Security Manager checks for hosts on your +local subnet(s). It defaults to nil. Usually, there should be no +need to set this non-nil, and doing that risks opening your local +network connections to attacks. So be sure you know what you are +doing before changing the value. + ++++ +** Native GnuTLS connections can now use client certificates. +Previously, this support was only available when using the external +'gnutls-cli' command. Call 'open-network-stream' with +':client-certificate t' to trigger looking up of per-server +certificates via 'auth-source'. + ++++ +** New user option 'network-stream-use-client-certificates'. +When non-nil, 'open-network-stream' performs lookups of client +certificates using 'auth-source' as if ':client-certificate t' were +specified if there is no explicit ':client-certificate' parameter. +Defaults to nil. + ++++ +** 'next/previous-multiframe-window' have been renamed. +The new names are as follows: + + 'next-multiframe-window' -> 'next-window-any-frame' + 'previous-multiframe-window' -> 'previous-window-any-frame' + +The old function names are maintained as aliases for backward +compatibility. + +** emacsclient ++++ +*** emacsclient now supports the 'EMACS_SOCKET_NAME' environment variable. +The command-line argument '--socket-name' overrides it. +(The same behavior as for the pre-existing 'EMACS_SERVER_FILE' variable.) + ++++ +*** Emacs and emacsclient now default to "$XDG_RUNTIME_DIR/emacs". +This is used as the directory for client/server sockets, if Emacs is +running on a platform or environment that sets the 'XDG_RUNTIME_DIR' +environment variable to indicate where session sockets should go. +To get the old, less-secure behavior, you can set the +'EMACS_SOCKET_NAME' environment variable to an appropriate value. + +--- +*** When run by root, emacsclient no longer connects to non-root sockets. +(Instead you can use Tramp methods to run root commands in a non-root Emacs.) + +--- +** 'xft-ignore-color-fonts' now ignores even more color fonts. +There are color fonts that managed to bypass the existing checks, +causing XFT crashes, they are now filtered out. Setting +'xft-ignore-color-fonts' to nil removes those checks, which might +require setting 'face-ignored-fonts' to filter out problematic fonts. +Known problematic fonts are "Noto Color Emoji" and "Emoji One". + +--- +** The GTK+ font chooser now respects 'face-ignored-fonts'. +When using 'menu-set-font' under GTK3, the available fonts are now +matched against 'face-ignored-fonts'. + +--- +** The GTK+ font chooser now remembers the previously selected settings. +It now remembers the name, size, style, etc. + ++++ +** New user option 'what-cursor-show-names'. +When non-nil, 'what-cursor-position' will show the name of the character +in addition to the decimal/hex/octal representation. Default nil. + ++++ +** New function 'network-lookup-address-info'. +This does IPv4 and/or IPv6 address lookups on hostnames. + ++++ +** 'network-interface-list' can now return IPv4 and IPv6 addresses. +IPv4 and IPv6 addresses are now returned by default if available, +optionally including netmask/broadcast address information. + +--- +** Control of the threshold for using the 'distant-foreground' color. +The threshold for color distance below which the 'distant-foreground' +color of the face will be used instead of the foreground color can now +be controlled via the new variable 'face-near-same-color-threshold'. +The default value is 30000, as the previously hard-coded threshold. + ++++ +** The function 'read-passwd' uses "*" as default character to hide passwords. + +** The function 'read-answer' now accepts not only single character +answers, but also function keys like 'F1', character events such as +'C-M-h', and control characters like 'C-h'. + +** Lexical binding is now used when evaluating interactive Elisp forms. +More specifically, 'lexical-binding' is now used for 'M-:', '--eval', +as well as in 'lisp-interaction-mode' and 'ielm-mode', used in the +"*scratch*" and "*ielm*" buffers. + +--- +** The new user option 'tooltip-resize-echo-area' avoids truncating +tooltip text on GUI frames when tooltips are displayed in the echo +area. Instead, it resizes the echo area as needed to accommodate the +full tool-tip text. + +--- +** Show mode line tooltips only if the corresponding action applies. +Customize the user option 'mode-line-default-help-echo' to restore the +old behavior where the tooltip text is also shown when the +corresponding action does not apply. + ++++ +** New hook 'server-after-make-frame-hook'. +This hook is a convenient place to perform initializations in daemon +mode which require GUI features to be available. One example is +restoration of the previous session using the desktop.el package: put +the call to 'desktop-read' in this hook, if you want the GUI settings +to be restored, or if desktop.el needs to interact with you during +restoration of the session. + ++++ +** The functions 'set-frame-height' and 'set-frame-width' are now +commands, and will set the currently selected frame to the height/ +width specified by the numeric prefix. + ++++ +** New function 'logcount' calculates an integer's Hamming weight. + ++++ +** New function 'libxml-available-p'. +This function returns non-nil if libxml support is both compiled in +and available at run time. Lisp programs should use this function to +detect built-in libxml support, instead of testing for that +indirectly, e.g., by checking that functions like +'libxml-parse-html-region' return nil. + ++++ +** 'libxml-parse-xml-region' and 'libxml-parse-html-region' take +a parameter that's called DISCARD-COMMENTS, but it really only +discards the top-level comment. Therefore this parameter is now +obsolete, and the new utility function 'xml-remove-comments' can be +used to remove comments before calling the libxml functions to parse +the data. + ++++ +** A new DOM (the XML/HTML document structure returned by functions +such as 'libxml-parse-html-region') traversal function has been added: +'dom-search', which takes a DOM and a predicate and returns all nodes +that match. + ++++ +** New function 'fill-polish-nobreak-p', to be used in 'fill-nobreak-predicate'. +It blocks line breaking after a one-letter word, also in the case when +this word is preceded by a non-space, but non-alphanumeric character. + ++++ +** The limit on repetitions in regexps has been raised to 2^16-1. +It was previously limited to 2^15-1. For example, the following +regular expression was previously invalid, but is now accepted: + + x\{32768\} + +--- +** The German prefix and postfix input methods now support Capital sharp S. + +--- +** New input methods 'hawaiian-postfix' and 'hawaiian-prefix'. + +--- +** New input methods 'georgian-qwerty' and 'georgian-nuskhuri'. + +--- +** New input methods for several variants of the Sami language. +The Sami input methods include: 'norwegian-sami-prefix', +'bergsland-hasselbrink-sami-prefix', 'southern-sami-prefix', +'ume-sami-prefix', 'northern-sami-prefix', 'inari-sami-prefix', +'skolt-sami-prefix', and 'kildin-sami-prefix'. + ++++ +** Japanese environments use UTF-8 by default. +In Japanese environments that do not specify encodings and are not +based on MS-Windows, the default encoding is now utf-8 instead of +japanese-iso-8bit. + ++++ +** New function 'exec-path'. +This function by default returns the value of the corresponding +user option, but can optionally return the equivalent of 'exec-path' +from a remote host. + ++++ +** The function 'executable-find' supports an optional argument REMOTE. +This triggers searching for the program on the remote host as indicated by +'default-directory'. + ++++ +** New user option 'auto-save-no-message'. +When set to t, no message will be shown when auto-saving (default +value: nil). + +--- +** The value of 'make-cursor-line-fully-visible' can now be a function. +In addition to nil or non-nil, the value can now be a predicate +function. Follow mode uses this to control scrolling of its windows +when the last screen line in a window is not fully visible. + ++++ +** New variable 'emacs-repository-branch'. +It reports the git branch from which Emacs was built. + ++++ +** New user option 'switch-to-buffer-obey-display-actions'. +When non-nil, 'switch-to-buffer' uses 'pop-to-buffer-same-window' that +respects display actions specified by 'display-buffer-alist' and +'display-buffer-overriding-action'. + ++++ +** The user option 'switch-to-visible-buffer' is now obsolete. +Customize 'switch-to-prev-buffer-skip' instead. + ++++ +** New user option 'switch-to-prev-buffer-skip'. +This user option allows specifying the set of buffers that may be +shown by 'switch-to-prev-buffer' and 'switch-to-next-buffer' more +stringently than the now obsolete 'switch-to-visible-buffer'. + +** New 'flex' completion style. +An implementation of popular "flex/fuzzy/scatter" completion which +matches strings where the pattern appears as a subsequence. Put +simply, makes "foo" complete to both "barfoo" and "frodo". Add 'flex' +to 'completion-styles' or 'completion-category-overrides' to use it. + +** The 'completion-common-part' face is now visible by default. + ++++ +** New face attribute ':extend' to control face extension at EOL. +The new face attribute ':extend' controls whether to use the face for +displaying the empty space beyond end of line (EOL) till the edge of +the window. By default, this attribute is non-nil only for a small +number of faces, notably, 'region'; any other face that crosses end of +line will not affect the display of the empty space at EOL. This is +to make Emacs behave more like other GUI applications with respect to +displaying faces that cross line boundaries. + +This attribute behaves specially when theme definitions are applied: +if the theme doesn't specify an explicit value of this attribute for a +face, the value from the original face definition is inherited. +Consequently, a theme generally shouldn't specify this attribute +unless it has a good reason to do so. + +** Connection-local variables ++++ +*** Connection-local variables are applied by default like file-local +and directory-local variables. + ++++ +*** The macro 'with-connection-local-variables' has been renamed from +'with-connection-local-profiles'. No argument PROFILES needed any longer. + +--- +** New user option 'next-error-verbose' controls when 'next-error' +outputs a message about the error locus. + +--- +** New user option 'grep-search-path' defines the directories searched for +grep hits (this used to be controlled by 'compilation-search-path'). + +--- +** New user option 'emacs-lisp-compilation-search-path' defines the +directories searched for byte-compiler error messages (this used to +be controlled by 'compilation-search-path'). + +--- +** Multicolor fonts such as "Noto Color Emoji" can be displayed on +Emacs configured with Cairo drawing and linked with cairo >= 1.16.0. + ++++ +** Emacs now optionally displays a fill column indicator. +This is similar to what 'fill-column-indicator' package provides, but +much faster and compatible with 'show-trailing-whitespace'. + +Customize the buffer-local user options 'display-fill-column-indicator' +and 'display-fill-column-indicator-character' to activate the +indicator. + +The indicator is not displayed at all in minibuffer windows and +in tooltips, as it is not useful there. + +There are 2 new buffer local variables and 1 face to customize this +mode, they are described in the manual "(emacs) Display". + ++++ +** 'progress-reporter-update' now accepts an optional suffix string to display. + +--- +** New user option 'xref-file-name-display' controls the display of +file names in xref buffers. + +** New user option 'byte-count-to-string-function'. +It is used for displaying file sizes and disk space in some cases. + ++++ +** Emacs now interprets RGB triplets like HTML, SVG, and CSS do. +The X convention previously used differed slightly, particularly for +RGB triplets with a single hexadecimal digit per component. + +--- +** The toolbar now shows the equivalent key binding in its tooltips. + +--- +** The File menu-bar menu was re-arranged. +Print menu items moved to submenu, and also added the new entries for tabs. + +--- +** 'scroll-lock-mode' is now bound to the 'Scroll_Lock' key globally. +Note that this key binding will not work on MS-Windows systems if +'w32-scroll-lock-modifier' is non-nil. + +--- +** 'global-set-key', called interactively, now no longer downcases a +key binding with an upper case letter - if you can type it, you can +bind it. + ++++ +** 'read-from-minibuffer' now works with buffer-local history variables. +The HIST argument of 'read-from-minibuffer' now works correctly with +buffer-local variables. This means that different buffers can have +their own separated input history list if desired. + +** 'backup-by-copying-when-privileged-mismatch' applies to file gid, too. +In addition to checking the file owner uid, Emacs also checks that the +group gid is not greater than 'backup-by-copying-when-privileged-mismatch'; +if so, 'backup-by-copying-when-mismatch' will be forced on. + + +* Editing Changes in Emacs 27.1 + ++++ +** When asked to visit a large file, Emacs now offers to visit it literally. +Previously, Emacs would only ask for confirmation before visiting +large files. Now it also offers a third alternative: to visit the +file literally, as in 'find-file-literally', which speeds up +navigation and editing of large files. + ++++ +** 'zap-to-char' now uses the history of characters you used to zap to. +'zap-to-char' uses the new 'read-char-from-minibuffer' function to allow +navigating through the history of characters that have been input. +This is mostly useful for characters that have complex input methods +where inputting the character again may involve many keystrokes. + ++++ +** 'save-some-buffers' now has a new action in the prompt: 'C-f' will +exit the command and switch to the buffer currently being asked about. + +--- +** More commands support noncontiguous rectangular regions, namely +'upcase-dwim', 'downcase-dwim', 'capitalize-dwim', 'capitalize-region', +'upcase-initials-region', 'replace-string', 'replace-regexp', and +'delimit-columns-region'. + ++++ +** The new 'amalgamating-undo-limit' variable can be used to control +how many changes should be amalgamated when using the 'undo' command. + +--- +** The 'newline-and-indent' command (commonly bound to 'RET' in many +modes) now takes an optional numeric argument to specify how many +times is should insert newlines (and indent). + ++++ +** New command 'make-empty-file'. + +--- +** 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). + ++++ +** New user option 'electric-quote-replace-double'. +This option controls whether '"' is replaced in 'electric-quote-mode', +in addition to other quote characters. If non-nil, ASCII double-quote +characters that quote text "like this" are replaced by double +typographic quotes, “like this”, in text modes, and in comments in +non-text modes. + +--- +** New user option 'flyspell-case-fold-duplications'. +This option controls whether Flyspell mode considers consecutive words +to be duplicates if they are not in the same case. If non-nil, the +default, words are considered to be duplicates even if their letters' +case does not match. + +--- +** 'write-abbrev-file' now includes special properties. +'write-abbrev-file' now writes special properties like ':case-fixed' +for abbrevs that have them. + ++++ +** 'write-abbrev-file' skips empty tables. +'write-abbrev-file' now skips inserting a 'define-abbrev-table' form for +tables which do not have any non-system abbrevs to save. + ++++ +** The new functions and commands 'text-property-search-forward' and +'text-property-search-backward' have been added. These provide an +interface that's more like functions like 'search-forward'. + +--- +** 'add-dir-local-variable' now uses dotted pair notation syntax to +write alists of variables to ".dir-locals.el". This is the same +syntax that you can see in the example of a ".dir-locals.el" file in +the node "(emacs) Directory Variables" of the user manual. + ++++ +** Network connections using 'local' can now use IPv6. +'make-network-process' now uses the correct loopback address when +asked to use ':host 'local' and ':family 'ipv6'. + ++++ +** The new function 'replace-region-contents' replaces the current +region using a given replacement-function in a non-destructive manner +(in terms of 'replace-buffer-contents'). + ++++ +** The command 'replace-buffer-contents' now has two optional +arguments mitigating performance issues when operating on huge +buffers. + ++++ +** Dragging 'C-M-mouse-1' now marks rectangular regions. + ++++ +** The command 'delete-indentation' now operates on the active region. +If the region is active, the command joins all the lines in the +region. When there's no active region, the command works on the +current and the previous or the next line, as before. + ++++ +** You can now change the font size with the mouse wheel. +Scrolling the mouse wheel with the Ctrl key pressed will now act the +same as the 'C-x C-+' and 'C-x C--' commands. + + +* Changes in Specialized Modes and Packages in Emacs 27.1 + +--- +** New HTML mode skeleton 'html-id-anchor'. +This new command (which inserts an <a id="foo">_</a> skeleton) is +bound to 'C-c C-c #'. + ++++ +** New command 'font-lock-refontify'. +This is an interactive convenience function to be used when developing +font locking for a mode. It recomputes the font locking data and then +re-fontifies the buffer. + +--- +** Font Lock is smarter about fontifying unterminated strings and comments. +When you type a quote that starts a string, or a comment delimiter +that starts a comment, font-lock will not immediately refontify the +following characters in 'font-lock-string-face' or +'font-lock-comment-face'. Instead, it will delay the fontification +beyond the current line to give you a chance to close the string or +comment. This is controlled by the new user option +'jit-lock-antiblink-grace', which specifies the delay in seconds. The +default is 2 seconds; set to nil to get back the old behavior. + +--- +** The 'C' command in 'tar-mode' will now preserve the timestamp of +the extracted file if the new user option 'tar-copy-preserve-time' is +non-nil. + +--- +** 'autoconf-mode' is now used instead of 'm4-mode' for the +"acinclude.m4" / "aclocal.m4" / "acsite.m4" files. + +--- +** On GNU/Linux, 'M-x battery' will now list all batteries, no matter +what they're named, and the 'battery-linux-sysfs-regexp' variable has +been removed. + +** The 'list-processes' command now includes port numbers in the +network connection information (in addition to the host name). + +** The 'cl' package is now officially deprecated in favor of 'cl-lib'. + +--- +** desktop + +*** When called interactively with a prefix arg 'C-u', 'desktop-read' +now prompts the user for the directory containing the desktop file. + ++++ +** display-line-numbers-mode + +*** New faces 'line-number-major-tick' and 'line-number-minor-tick', +and user options 'display-line-numbers-major-tick' and +'display-line-numbers-minor-tick' can be used to highlight the line +numbers of lines multiple of certain numbers. + +*** New variable 'display-line-numbers-offset', when non-zero, adds +an offset to absolute line numbers. + ++++ +** winner + +*** A new user option, 'winner-boring-buffers-regexp', has been added. + +** table + +*** 'table-generate-source' and friends now support outputting wiki and +mediawiki format tables. + +--- +** telnet-mode + +*** Reverting a buffer in 'telnet-mode' will restart a closed connection. + +** goto-addr + +*** A way to more conveniently specify what URI address schemes should +be ignored has been added via the 'goto-address-uri-schemes-ignored' +variable. + ++++ +** tex-mode + +*** 'latex-noindent-commands' controls indentation of certain commands. +You can use this new user option to control indentation of arguments of +\emph, \footnote, and similar commands. + +** byte compiler + +*** 'byte-compile-dynamic' is now obsolete. +This is because on the one hand it suffers from misbehavior in corner +cases that have plagued it for years, and on the other experiments indicated +that it doesn't bring any measurable benefit. + +--- +*** The 'g' keystroke in "*Compile-Log*" buffers has been bound to a +new command that will recompile the file previously compiled with 'M-x +byte-compile-file' and the like. + +** compile.el + +--- +*** In 'compilation-error-regexp-alist', 'line' (and 'end-line') can +be functions. + ++++ +*** 'compilation-context-lines' can now take the value t; this is like +nil, but instead of scrolling the current line to the top of the +screen when there is no left fringe, it inserts a visible arrow before +column zero. + +--- +*** The new 'compilation-transform-file-match-alist' user option can +be used to transform file name matches compilation output, and remove +known false positives being recognized as warnings/errors. + +** cl-lib.el + ++++ +*** 'cl-defstruct' has a new ':noinline' argument to prevent inlining +its functions. + ++++ +*** 'cl-defstruct' slots accept a ':documentation' property. + +--- +*** 'cl-values-list' will now signal an error if its argument isn't a list. + +** doc-view.el + +*** New commands 'doc-view-presentation' and 'doc-view-fit-window-to-page'. + +*** Added support for password-protected PDF files. + +*** A new user option 'doc-view-pdftotext-program-args' has been added +to allow controlling how the conversion to text is done. + +** Ido + +*** New user option 'ido-big-directories' to mark directories whose +names match certain regular expressions as big. Ido won't attempt to +list the contents of such directories when completing file names. + +** Minibuffer + ++++ +*** A new user option, 'minibuffer-beginning-of-buffer-movement', has +been introduced to allow controlling how the 'M-<' command works in +the minibuffer. If non-nil, point will move to the end of the prompt +(if point is after the end of the prompt). + ++++ +*** When the minibuffer is active, echo-area messages are displayed at +the end of the minibuffer instead of hiding the minibuffer by the echo +area display. The new user option 'minibuffer-message-clear-timeout' +controls how messages displayed in this situation are removed from the +minibuffer. + +--- +*** Minibuffer now uses 'minibuffer-message' to display error messages +at the end of the active minibuffer. + ++++ +*** 'y-or-n-p' now uses the minibuffer to read 'y' or 'n' answer. + +--- +*** Some commands that previously used 'read-char-choice' now read +a character using the minibuffer by 'read-char-from-minibuffer'. + +** map.el + +*** Now also understands plists. +*** Now defined via generic functions that can be extended via 'cl-defmethod'. +*** Deprecate the 'map-put' macro in favor of a new 'map-put!' function. +*** 'map-contains-key' now returns a boolean rather than the key. +*** Deprecate the 'testfn' args of 'map-elt' and 'map-contains-key'. +*** New generic function 'map-insert'. ++++ +*** The 'type' arg can be a list '(hash-table :key1 VAL1 :key2 VAL2 ...)'. + +** seq.el +New convenience functions 'seq-first' and 'seq-rest' give easy access +to respectively the first and all but the first elements of sequences. + +The new predicate function 'seq-contains-p' should be used instead of +the now obsolete 'seq-contains'. + +--- +** Follow mode +In the current follow group of windows, "ghost" cursors are no longer +displayed in the non-selected follow windows. To get the old behavior +back, customize 'follow-hide-ghost-cursors' to nil. + ++++ +** New variable 'warning-fill-column' for 'display-warning'. + +** Windmove + +--- +*** 'windmove-create-window' when non-nil makes a new window. +This happens upon moving off the edge of the frame. + +--- +*** Windmove supports directional window display and selection. +The new command 'windmove-display-default-keybindings' binds default +keys with provided modifiers (by default, Shift-Meta) to the commands +that display the next buffer in the window at the specified direction. +This is like 'windmove-default-keybindings' that binds keys to commands +that select the window in the specified direction, but additionally it +displays the buffer from the next command in that window. For example, +'S-M-right C-h i' displays the "*Info*" buffer in the right window, +creating the window if necessary. A special key can be customized to +display the buffer in the same window, for example, 'S-M-0 C-h e' +displays the "*Messages*" buffer in the same window. 'S-M-t C-h C-n' +displays NEWS in a new tab. + +--- +*** Windmove also supports directional window deletion. +The new command 'windmove-delete-default-keybindings' binds default +keys with provided prefix (by default, 'C-x') and modifiers (by default, +'Shift') to the commands that delete the window in the specified +direction. For example, 'C-x S-down' deletes the window below. +With a prefix arg 'C-u', also kills the buffer in that window. +With 'M-0', deletes the selected window and selects the window +that was in the specified direction. + +--- +*** New command 'windmove-swap-states-in-direction' binds default keys +to the commands that swap the states of the selected window with the +window in the specified direction. + +--- +*** Windmove code no longer used is now obsolete. +That includes the user option 'windmove-window-distance-delta' and the +functions 'windmove-coord-add', 'windmove-constrain-to-range', +'windmove-constrain-around-range', 'windmove-frame-edges', +'windmove-constrain-loc-for-movement', 'windmove-wrap-loc-for-movement', +'windmove-reference-loc' and 'windmove-other-window-loc'. + +** Octave mode +The mode is automatically enabled in files that start with the +'function' keyword. + +** project.el + +*** New commands 'project-search' and 'project-query-replace-regexp'. +*** New user option 'project-read-file-name-function'. + +** Etags + ++++ +*** 'next-file' is now an obsolete alias of 'tags-next-file'. + +--- +*** 'tags-loop-revert-buffers' is an obsolete alias of +'fileloop-revert-buffers'. + ++++ +*** The 'tags-loop-continue' function along with the +'tags-loop-operate' and 'tags-loop-scan' variables are now obsolete; +use the new 'fileloop-initialize' and 'fileloop-continue' functions +instead. + ++++ +*** etags is now able to read Zstandard-compressed files. + +** bibtex + +--- +*** New commands 'bibtex-next-entry' and 'bibtex-previous-entry'. +In 'bibtex-mode-map', 'forward-paragraph' and 'backward-paragraph' are +remapped to these, respectively. + +** Dired + +--- +*** On systems that support suid/guid files, Dired now fontifies the +permissions of such files with a special face 'dired-set-id'. + ++++ +*** New command 'dired-create-empty-file'. + ++++ +*** New command 'dired-number-of-marked-files'. +It is by default bound to '* N'. + +--- +*** The marking commands now report how many files were marked by the +command itself, not how many files are marked in total. + +--- +*** A new face, 'dired-special', is used to highlight sockets, named +pipes, block devices and character devices. + ++++ +*** The new user option 'dired-create-destination-dirs' controls whether +'dired-do-copy' and 'dired-rename-file' should create non-existent +directories in the destination. + ++++ +*** 'dired-dwim-target' can be customized to prefer either the next window, +or one of the most recently visited windows with a Dired buffer. + ++++ +*** When the new user option 'dired-vc-rename-file' is non-nil, +Dired performs file renaming using underlying version control system. + +--- +*** Zstandard compression is now supported for 'dired-do-compress' and +'dired-do-compress-to'. + +** Find-Dired + +--- +*** New user option 'find-dired-refine-function'. +The default value is 'find-dired-sort-by-filename'. + +--- +*** New sorting options for the user option 'find-ls-option'. + +** Change Logs and VC + +--- +*** New user option 'vc-tor'. +When non-nil, this user option causes the VC commands to communicate +with the repository via Tor's proxy, using the 'torsocks' wrapper +script. The default is nil. + ++++ +*** New command 'log-edit-generate-changelog-from-diff', bound to 'C-c C-w'. +This generates ChangeLog entries from the VC fileset diff. + +--- +*** 'vc-dir' now shows a button allowing you to hide the stash list. +Controlled by user option 'vc-git-show-stash'. Default t means show +the entire list as before. An integer value limits the list length +(but still allows you to show the entire list via the button). + ++++ +*** Recording ChangeLog entries doesn't require an actual file. +If a ChangeLog file doesn't exist, and if the new user option +'add-log-dont-create-changelog-file' is non-nil (which is the +default), commands such as 'C-x 4 a' will add log entries to a +suitable named temporary buffer. (An existing ChangeLog file will +still be used if it exists.) Set the user option to nil to get the +previous behavior of always creating a buffer that visits a ChangeLog +file. + +--- +*** New user option 'vc-find-revision-no-save'. +With non-nil, 'vc-find-revision' doesn't write the created buffer to file. + +--- +*** 'vc-dir-ignore' now takes a prefix argument to ignore all marked files. + +--- +*** New user option 'vc-git-grep-template'. +This new user option allows customizing the default arguments passed to +'git-grep' when 'vc-git-grep' is used. + +--- +*** Command 'vc-git-stash' now respects marks in the "*vc-dir*" buffer. +When some files are marked, only those are stashed. +When no files are marked, all modified files are stashed, as before. + +--- +*** 'vc-git-stash' is now bound to 'C' in the stash headers. + +-- +*** Some stash keybindings are now available in the stash button. +'vc-git-stash' and 'vc-git-stash-snapshot' can now be run using 'C' +and 'S' respectively, including when there are no stashes. + +--- +*** The new hook 'vc-retrieve-tag-hook' runs after retrieving a tag. + +--- +*** 'vc-hg' now invokes 'smerge-mode' when visiting files. +Code that attempted to invoke 'smerge-mode' when visiting an Hg file +with conflicts existed in earlier versions of Emacs, but incorrectly +never detected a conflict due to invalid assumptions about cached +values. + ++++ +*** The Hg (Mercurial) back-end now supports 'vc-region-history'. +The 'C-x v h' command now works in buffers that visit files controlled +by Hg. + ++++ +*** The Hg (Mercurial) back-end now prompts for revision to merge when +you invoke 'C-x v m' ('vc-merge'). + +--- +*** The Hg (Mercurial) back-end now uses tags, branches and bookmarks +instead of revision numbers as completion candidates when it prompts +for a revision. + ++++ +*** 'C-u C-x v D' ('vc-root-version-diff') prompts for two revisions +and compares their entire trees. + +*** New user option 'vc-hg-revert-switches'. +It specifies switches to pass to Hg's 'revert' command. + +*** 'C-x v M D' ('vc-diff-mergebase') and 'C-x v M L' ('vc-log-mergebase') +print diffs and logs between the merge base (common ancestor) of two +given revisions. + ++++ +*** The new 'd' command ('vc-dir-clean-files') in 'vc-dir-mode' +buffers will delete the marked files (or if no files are marked, the +file under point). This command does not notify the VC backend, and +is mostly useful for unregistered files. + ++++ +*** New command 'vc-log-search' asks for a pattern, searches it +in the revision log, and displays matched log entries in the +log buffer. For example, 'M-x vc-log-search RET bug#36644 RET' +displays all entries whose log messages match the bug number. +With a prefix argument asks for a command, so for example, +'C-u M-x vc-log-search RET git log -1 f302475 RET' will display +just one log entry found by its revision number. + ++++ +*** It is now possible to display a specific revision given by its ID. +If you invoke 'C-x v L' ('vc-print-root-log') with a numeric argument +of 1, as in 'C-1 C-x v L' or 'C-u 1 C-x v L', it asks for a revision +ID, and shows its log entry together with the diffs introduced by the +revision's commit. (For some less capable VCSes, only the log entry +is shown.) + +--- +*** 'C-x v =' can now mimic Magit's diff format. +Set the new user option 'diff-font-lock-prettify' to t for that, see +below under "Diff mode". + +--- +*** The 'diff' function arguments OLD and NEW may each be a buffer +rather than a file, in non-interactive calls. This change was made in +Emacs 24.1, but wasn't documented until now. + ++++ +*** New command 'diff-buffers' interactively diffs two buffers. + +** Diff mode + ++++ +*** Hunks are now automatically refined by font-lock. +To disable refinement, set the new user option 'diff-refine' to nil. +To get back the old behavior where hunks are refined as you navigate +through a diff, set 'diff-refine' to the symbol 'navigate'. + ++++ +*** 'diff-auto-refine-mode' is deprecated in favor of 'diff-refine'. +It is no longer enabled by default and binding it no longer has any +effect. + ++++ +*** Better syntax highlighting of Diff hunks. +Fragments of source in Diff hunks are now by default highlighted +according to the appropriate major mode. Customize the new user +option 'diff-font-lock-syntax' to nil to disable this. + +--- +*** File headers can be shortened, mimicking Magit's diff format. +To enable it, set the new user option 'diff-font-lock-prettify' to t. +On GUI frames, this option also displays the insertion and deletion +indicators on the left fringe. + ++++ +*** Prefix arg of 'diff-goto-source' means jump to the old revision +of the file under version control if point is on an old changed line, +or to the new revision of the file otherwise. + +** Texinfo + ++++ +*** New function for inserting '@pxref', '@xref', or '@ref' commands. +The function 'texinfo-insert-dwim-@ref', bound to 'C-c C-c r' by +default, inserts one of three types of references based on the text +surrounding point, namely '@pxref' near a parenthesis, '@xref' at the +start of a sentence or at '(point-min)', else '@ref'. + +** Browse-url + +--- +*** The function 'browse-url-emacs' can now visit a URL in selected window. +It now treats the optional 2nd argument to mean that the URL should be +shown in the currently selected window. + +--- +*** A new function, 'browse-url-add-buttons' can be used to add clickable +links to most ordinary special-mode buffers that display text that +have URLs embedded. 'browse-url-button-regexp' controls what's +considered a button. + +--- +*** New user option 'browse-url-secondary-browser-function'. +It can be set to a function that invokes an alternative browser. + +** Comint + ++++ +*** 'send-invisible' is now an obsolete alias for 'comint-send-invisible'. +Also, 'shell-strip-ctrl-m' is declared obsolete. + ++++ +*** 'C-c .' ('comint-insert-previous-argument') no longer interprets '&'. +This feature caused problems when '&&' was present in the previous +command. Since this command emulates 'M-.' in Bash and zsh, neither +of which treats '&' specially, the feature was removed for +compatibility with these shells. + ++++ +*** 'comint-insert-previous-argument' can now count arguments from the end. +By default, invoking 'C-c .' with a numeric argument N would copy the +Nth argument, counting from the first one. But if the new user option +'comint-insert-previous-argument-from-end' is non-nil, it will copy +the Nth argument counting from the last one. Thus 'C-c .' can now +better emulate 'M-.' in both Bash and zsh, since the former counts +from the beginning of the arguments, while the latter counts from the +end. + ++++ +*** 'comint-run' can now accept a list of switches to pass to the program. +'C-u M-x comint-run' will prompt for the switches interactively. + ++++ +*** Abnormal hook 'comint-password-function' has been added. +This hook permits a derived mode to supply a password for the +underlying command interpreter without prompting the user. For +example, in 'sql-mode', the password for connecting to the database may +be stored in the connection wallet and may be passed on the command +line to start the SQL interpreter. This is a potential security flaw +that could expose user's database passwords on the command line +through the use of a process list (Bug#8427). With this hook, it is +possible to not pass the password on the command line and wait for the +program to prompt for the password. When it does so, the password can +be supplied to the SQL interpreter without involving the user just as +if it had been supplied on the command line. + +** SQL + +--- +*** SQL Indent Minor Mode +SQL Mode now supports the ELPA 'sql-indent' package for assisting +sophisticated SQL indenting rules. Note, however, that SQL is not +like other programming languages like C, Java, or Python where code is +sparse and rules for formatting are fairly well established. Instead +SQL is more like COBOL (from which it came) and code tends to be very +dense and line ending decisions driven by syntax and line length +considerations to make readable code. Experienced SQL developers may +prefer to rely upon existing Emacs facilities for formatting code but +the 'sql-indent' package provides facilities to aid more casual SQL +developers layout queries and complex expressions. + +--- +**** 'sql-use-indent-support' (default t) enables SQL indention support. +The 'sql-indent' package from ELPA must be installed to get the +indentation support in 'sql-mode' and 'sql-interactive-mode'. + +--- +**** 'sql-mode-hook' and 'sql-interactive-mode-hook' changed. +Both hook variables have had 'sql-indent-enable' added to their +default values. If you have existing customizations to these +variables, you should make sure that the new default entry is +included. + +--- +*** Connection Wallet +Database passwords can now by stored in NETRC or JSON data files that +may optionally be encrypted. When establishing an interactive session +with the database via 'sql-connect' or a product specific function, +like 'sql-mysql' or 'sql-postgres', the password wallet will be +searched for the password. The 'sql-product', 'sql-server', +'sql-database', and the 'sql-username' will be used to identify the +appropriate authorization. This eliminates the discouraged practice of +embedding database passwords in your Emacs initialization. + +See the 'auth-source' module for complete documentation on the file +formats. By default, the wallet file is expected to be in the +'user-emacs-directory', named "sql-wallet" or ".sql-wallet", with +".json" (JSON) or no (NETRC) suffix. Both file formats can optionally +be encrypted with GPG by adding an additional ".gpg" suffix. + +** Term + +--- +*** 'term-read-noecho' is now obsolete, use 'read-passwd' instead. + ++++ +*** 'serial-term' now takes an optional parameter to leave the +emulator in line mode. + +** Flymake + ++++ +*** The variable 'flymake-diagnostic-types-alist' is obsolete. +You should instead set properties on known diagnostic symbols, like +':error' and ':warning', as demonstrated in the Flymake manual. + ++++ +*** New user option 'flymake-start-on-save-buffer'. +Control whether Flymake starts checking the buffer on save. + +--- +*** Flymake and backend functions may exchange hints about buffer changes. +This enables more efficient backends. See the docstring of +'flymake-diagnostic-functions' or the Flymake manual for details. + ++++ +*** 'flymake-start-syntax-check-on-newline' is now obsolete, +use 'post-self-insert-hook' to check on newline. + +** Ruby + +--- +*** The Rubocop Flymake diagnostic function will only run Lint cops if +it can't find the config file. + +--- +*** Rubocop is called with 'bundle exec' if Gemfile mentions it. + +--- +*** New command 'ruby-find-library-file' bound to 'C-c C-f'. + +** Package + +--- +*** Warn if "footer line" is missing, but still install package. +package.el used to refuse to install a package without the so-called +"footer line", which appears at the very end of the file: + +;;; FILENAME ends here + +package.el will now install packages without this line, but it will +issue a warning. To avoid this warning, packages should keep the +"footer line". + +Note that versions of Emacs older than 27.1 will not only refuse to +install packages without such a line -- they will be unable to parse +package data. It is therefore recommended to keep this line. + ++++ +*** Change of 'package-check-signature' for packages with multiple sigs. +In previous Emacsen, t checked that all signatures are valid. +Now t only checks that at least one signature is valid and the new 'all' +value needs to be used if you want to enforce that all signatures +are valid. This only affects packages with multiple signatures. + ++++ +*** The meaning of 'allow-unsigned' in 'package-check-signature' has +changed slightly: If a usable OpenPGP configuration can't be found +(for instance, if gpg isn't installed), it now has the same meaning as +nil. + +--- +*** New function 'package-get-version' lets packages query their own version. +Example use in auctex.el: '(defconst auctex-version (package-get-version))' + +--- +*** New 'package-quickstart' feature. +When 'package-quickstart' is non-nil, package.el precomputes a big +autoloads file so that activation of packages can be done much faster, +which can speed up your startup significantly. +It also causes user options like 'package-user-dir' and +'package-load-list' to be consulted when 'package-quickstart-refresh' +is run rather than at startup so you don't need to set them in your +early init file. + +--- +*** New function 'package-activate-all'. + ++++ +*** New functions for filtering packages list. +A new function has been added which allows users to filter the +packages list by name: 'package-menu-filter-by-name'. By default, it +is bound to '/ n'. Additionally, the function +'package-menu-filter-by-keyword' has been renamed from +'package-menu-filter'. Its keybinding has also been changed to '/ k' +(from 'f'). To clear any of the two filters, the user can now call +the 'package-menu-clear-filter' function, bound to '/ /' by default. + +--- +*** Imenu support has been added to 'package-menu-mode'. + +--- +*** The package list can now be sorted by version or description. + ++++ +*** In Package Menu, 'g' now updates package data from archives. +Previously, 'g' invoked 'tabulated-list-revert' which did not update +the cached archive data. It is now bound to 'revert-buffer', which +will update the data. + +'package-menu-refresh' is an obsolete alias for 'revert-buffer'. + +** Info + ++++ +*** Clicking on the left/right arrow icon in the Info tool-bar while +holding down the Ctrl key pops up a menu of previously visited Info nodes +where you can select a node to go back (like in browsers). + +--- +*** Info can now follow 'file://' protocol URLs. +The 'file://' URLs in Info documents can now be followed by passing +them to the 'browse-url' function, like the other protocols: 'ftp', +'http', and 'https'. This allows having references to local HTML +files, for example. + +--- +** Display of man pages now limits the width for formatting pages. +The new user option 'Man-width-max' (80 by default) limits the number +of columns passed to the 'man' program for formatting man pages. This +is to enhance readability when man pages are displayed in very wide +windows (which are customary with today's large displays). + +** Xref + ++++ +*** New command 'xref-find-definitions-at-mouse'. +This command finds definitions of the identifier at the place of a +mouse click event, and is intended to be bound to a mouse event. + ++++ +*** Changing 'xref-marker-ring-length' works after xref.el is loaded. +Previously, setting 'xref-marker-ring-length' would only take effect +if set before xref.el was loaded. + +--- +*** 'xref-find-definitions' now sets the mark at the buffer position +where it was invoked. + +--- +*** New xref faces 'xref-file-header', 'xref-line-number', 'xref-match'. + +--- +*** New user option 'xref-show-definitions-function'. +It encapsulates the logic pertinent to showing the result of +'xref-find-definitions'. The user can change it to customize its +behavior and the display of results. + +--- +*** Search results show the buffer even for one hit. +The search-type Xref commands (e.g. 'xref-find-references' or +'project-find-regexp') now show the results buffer even when there is +only one hit. This can be altered by changing 'xref-show-xrefs-function'. + ++++ +*** Xref buffers support refreshing the search results. +A new command 'xref-revert-buffer' is bound to 'g'. + +--- +*** Imenu support has been added to 'xref--xref-buffer-mode'. + +*** New generic method 'xref-backend-identifier-completion-ignore-case'. +Using it, the etags backend now honors 'tags-case-fold-search' during +identifier completion. + +** Checkdoc + +--- +*** Checkdoc can now optionally spell-check doc strings. +Invoking 'checkdoc-buffer' with a non-nil TAKE-NOTES argument +(interactively, with a prefix arg) will now spell-check the doc +strings and report all the spelling mistakes. + +** Icomplete + ++++ +*** New minor mode Fido mode. +This mode is based on Icomplete, and its name stands for "Fake Ido". +The point of this mode is to be an 'ido-mode' workalike, but provide +most of the functionality present in Icomplete that is not in +'ido-mode', while being much more compatible with all of Emacs's +completion facilities. + +** Ecomplete + +--- +*** The Ecomplete sorting has changed to a decay-based algorithm. +This can be controlled by the new 'ecomplete-sort-predicate' user option. + +--- +*** The 'ecomplete-database-file' file is now placed in +"~/.emacs.d/ecompleterc" by default. Of course it will still find it +if you have it in "~/.ecompleterc". + +** Gnus + +--- +*** 'mm-uu-diff-groups-regexp' now defaults to matching all groups, +which means that "git am" diffs are recognized everywhere. + ++++ +*** Two new Gnus summary mode navigation commands have been added, +bound to the '[' and ']' keys: 'gnus-summary-prev-unseen-article' and +'gnus-summary-next-unseen-article'. These take you (respectively) to +the previous unseen or next unseen article. (These are the ones that +are marked with "." in the summary mode lines.) + ++++ +*** The Gnus user variable 'nnimap-expunge' supports three new values: +'never' for never expunging messages, 'immediately' for immediately +expunging deleted messages, and 'on-exit' to expunge deleted articles +when exiting the group's summary buffer. Setting 'nnimap-expunge' to +nil or t is still supported but not recommended, since it may +result in Gnus expunging all messages that have been flagged as +deleted by any IMAP client (rather than just those that have been +deleted by Gnus). + ++++ +*** New user option 'gnus-use-atomic-windows' makes Gnus window layouts atomic. +See the "(elisp) Atomic Windows" node of the Elisp manual for details. + ++++ +*** There's a new value for 'gnus-article-date-headers', +'combined-local-lapsed', which will show both the time (in the local +timezone) and the lapsed time. + +--- +*** Gnus now maps imaps to 993 only on old MS-Windows versions. +The nnimap backend used to do this unconditionally to work around +problems on old versions of MS-Windows. This is now done only for +Windows XP and older. + ++++ +*** The nnimap backend now has support for IMAP namespaces. +This feature can be enabled by setting the new 'nnimap-use-namespaces' +server variable to non-nil. + ++++ +*** A prefix argument to 'gnus-summary-limit-to-score' will limit in reverse. +Limit to articles with score "at or below" the SCORE argument rather +than "at or above". + +--- +*** The function 'gnus-score-find-favorite-words' has been renamed +from 'gnus-score-find-favourite-words'. + +--- +*** Gmane has been removed as an nnir backend, since Gmane no longer +has a search engine. + ++++ +*** Splitting mail on common mailing list headers has been added. +See the concept index in the Gnus manual for the 'match-list' entry. + ++++ +*** nil is no longer an allowed value for 'mm-text-html-renderer'. + ++++ +*** The default value of 'mm-inline-large-images' has changed from nil +to 'resize', which means that large images will be resized instead of +displayed with an external program by default. + ++++ +*** A new Gnus summary mode command, 'S A' ('gnus-summary-attach-article') +can be used to attach the current article(s) to a pre-existing Message +buffer, or create a new Message buffer with the article(s) attached. + ++++ +*** A new Gnus summary mode command, 'w' ('gnus-summary-browse-url') +scans the article buffer for URLs, and offers them to the user to open +with 'browse-url'. + +--- +*** New user option 'nnir-notmuch-filter-group-names-function'. +This option controls whether and how to use Gnus search groups as +'path:' search terms to 'notmuch'. + +--- +*** The buttons in the Gnus article buffer were formerly widgets +(i.e., buttons from widget.el). This has now changed, and they are +now buttons (from button.el), and commands like 'TAB' now search for +buttons instead of widgets. There should be no user-visible changes, +but out-of-tree code that relied on widgets being present might now +fail. + +** erc + +--- +*** New hook 'erc-insert-done-hook'. +This hook is called after strings have been inserted into the buffer, +and is free to alter point and window configurations, as it's not +called from inside a 'save-excursion', as opposed to 'erc-insert-post-hook'. + +--- +*** 'erc-button-google-url' has been renamed to 'erc-button-search-url' +and its value has been changed to Duck Duck Go. + +--- +*** 'erc-send-pre-hook' and 'erc-send-this' have been obsoleted. +The user option to use instead to alter text to be sent is now +'erc-pre-send-functions'. + +--- +*** Improve matching/highlighting of nicknames. +Open and close parenthesis and apostrophe are not considered valid +nick characters anymore, matching the given grammar in RFC 2812 +section 2.3.1. This enables correct matching and highlighting of +nicks when they are surrounded by parentheses, like "(nick)", and when +adjacent to an apostrophe, like "nick's". + +--- +*** Set 'erc-button-url-regexp' to 'browse-url-button-regexp' +which better handles surrounding pair of parentheses. + +** EUDC + +--- +*** XEmacs support has been removed. + +** eww/shr + ++++ +*** The new user option 'shr-cookie-policy' can be used to control +when to use cookies when fetching embedded images. The default is to +use them when the images are from the same domain as the main HTML +document. + ++++ +*** The 'eww' command can now create a new EWW buffer. +Invoking the command with a prefix argument will cause it to create a +new EWW buffer for the URL instead of reusing the default one. + ++++ +*** Clicking with the Ctrl key or 'C-u RET' on a link opens a new tab +when tab-bar-mode is enabled. + ++++ +*** The 'd' ('eww-download') command now falls back to current page's URL. +If this command is invoked with no URL at point, it now downloads the +current page instead of signaling an error. + +*** When opening external links in eww/shr (typically with the +'C-u RET' keystroke on a link), the link will be flashed with the new +'shr-selected-link' face to give the user feedback that the command +has been executed. + ++++ +*** New user option 'shr-discard-aria-hidden'. +If set, shr will not render tags with attribute 'aria-hidden="true"'. +This attribute is meant to tell screen readers to ignore a tag. + ++++ +*** 'shr-external-browser' has been made into an obsolete alias +of 'browse-url-secondary-browser-function'. + +--- +*** 'shr-tag-ol' now respects the ordered list 'start' attribute. + +--- +*** The following tags are now handled: '<code>', '<abbr>', and '<acronym>'. + +** Htmlfontify + ++++ +*** The functions 'hfy-color', 'hfy-color-vals' and +'hfy-fallback-color-values' and the variables 'hfy-fallback-color-map' +and 'hfy-rgb-txt-color-map' have been renamed from names that used +'colour' instead of 'color'. + ++++ +** Enriched mode supports the 'charset' text property. +You can add or modify the 'charset' text properties of text using the +'Edit->Text Properties->Special Properties' menu, or by invoking the +'facemenu-set-charset' command. Documents in Enriched mode will be +saved with the charset properties, and those properties will be +restored when the file is visited. + +** Smtpmail + +--- +*** Authentication mechanisms can be added via external packages, by +defining new 'cl-defmethod' of 'smtpmail-try-auth-method'. + ++++ +*** To always force smtpmail to send credentials over on the first +attempt when communicating with the SMTP server(s), the +'smtpmail-servers-requiring-authorization' user option can be used. + ++++ +*** smtpmail will now try resending mail when getting a transient "4xx" +error message from the SMTP server. The new 'smtpmail-retries' +user option says how many times to retry. + +** Footnote mode + +--- +*** Support Hebrew-style footnotes. + +--- +*** Footnote text lines are now aligned. +Can be controlled via the new user option 'footnote-align-to-fn-text'. + +** CSS mode + +--- +*** A new command 'css-cycle-color-format' for cycling between color +formats (e.g. "black" => "#000000" => "rgb(0, 0, 0)") has been added, +bound to 'C-c C-f'. + +--- +*** CSS mode, SCSS mode, and Less CSS mode now have support for Imenu. + +** SGML mode + +--- +*** 'sgml-quote' now handles double quotes and apostrophes +when escaping text and in addition all numeric entities when +unescaping text. + +** Python mode + +--- +*** Python mode supports three different font lock decoration levels. +The maximum level is used by default; customize +'font-lock-maximum-decoration' to tone down the decoration. + +--- +*** New user option 'python-pdbtrack-kill-buffers'. +If non-nil, the default, buffers opened during pdbtracking session are +killed when pdbtracking session is finished. + +--- +*** New function 'python-shell-send-statement. +It sends the statement delimited by 'python-nav-beginning-of-statement' +and 'python-nav-end-of-statement' to the inferior Python process. + +** Help + +--- +*** Descriptions of variables and functions give an estimated first release +where the variable or function appeared in Emacs. + +--- +*** Output format of 'C-h l' ('view-lossage') has changed. +For convenience, 'view-lossage' now displays the last keystrokes +and commands in the same format as the edit buffer of +'edit-last-kbd-macro'. This makes it possible to copy the lines from +the buffer generated by 'view-lossage' to the "*Edit Macro*" buffer +created by 'edit-last-kbd-macro', and to save the macro by 'C-c C-c'. + +--- +*** The list of help commands produced by 'C-h C-h' ('help-for-help') +can now be searched via 'C-s'. + +** Ibuffer + +--- +*** New filter 'ibuffer-filter-by-process'; bound to '/ E'. + +--- +*** All mode filters can now accept a list of symbols. +This means you can now easily filter several major modes, as well +as a single mode. + +** Search and Replace + ++++ +*** Isearch supports a prefix argument for 'C-s' ('isearch-repeat-forward') +and 'C-r' ('isearch-repeat-backward'). With a prefix argument, these +commands repeat the search for the specified occurrence of the search string. +A negative argument repeats the search in the opposite direction. +This makes possible also to use a prefix argument for 'M-s .' +('isearch-forward-symbol-at-point') to find the next Nth symbol. +Also a prefix argument is supported for 'isearch-yank-until-char', +'isearch-yank-word-or-char', 'isearch-yank-symbol-or-char'. + ++++ +*** To go to the first/last occurrence of the current search string +is possible now with new commands 'isearch-beginning-of-buffer' and +'isearch-end-of-buffer' bound to 'M-s M-<' and 'M-s M->' in Isearch. +With a numeric argument, they go to the Nth absolute occurrence +counting from the beginning/end of the buffer. This complements +'C-s'/'C-r' that searches for the next Nth relative occurrence +with a numeric argument. + ++++ +*** 'isearch-lazy-count' shows the current match number and total number +of matches in the Isearch prompt. User options +'lazy-count-prefix-format' and 'lazy-count-suffix-format' define the +format of the current and the total number of matches in the prompt's +prefix and suffix, respectively. + +--- +*** 'lazy-highlight-buffer' highlights matches in the full buffer. +It is useful in combination with 'lazy-highlight-cleanup' customized to nil +to leave matches highlighted in the whole buffer after exiting isearch. +Also when 'lazy-highlight-buffer' prepares highlighting in the buffer, +navigation through the matches without flickering is more smooth. +'lazy-highlight-buffer-max-at-a-time' controls the number of matches to +highlight in one iteration while processing the full buffer. + ++++ +*** New isearch bindings. +'C-M-z' invokes new function 'isearch-yank-until-char', which yanks +everything from point up to but not including the specified +character into the search string. This is especially useful for +keyboard macros. + +'C-M-w' in isearch changed from 'isearch-del-char' to the new function +'isearch-yank-symbol-or-char'. 'isearch-del-char' is now bound to +'C-M-d'. + ++++ +'M-s h l' invokes 'highlight-lines-matching-regexp' using the search +string to highlight lines matching the search string. This is similar +to the existing binding 'M-s h r' ('highlight-regexp') that highlights +JUST the search string. + ++++ +*** New user option 'isearch-yank-on-move' provides options t and 'shift' +to extend the search string by yanking text that ends at the new +position after moving point in the current buffer. 'shift' extends +the search string by motion commands while holding down the shift key. + ++++ +*** 'isearch-allow-scroll' provides a new option 'unlimited' to allow +scrolling any distance off screen. + +--- +*** Isearch now remembers the regexp-based search mode for words/symbols +and case-sensitivity together with search strings in the search ring. + +--- +*** Isearch now has its own tool-bar and menu-bar menu. + ++++ +*** 'flush-lines' prints and returns the number of deleted matching lines. + +--- +*** 'char-fold-to-regexp' now matches more variants of a base character. +The table used to check for equivalence of characters is now built +using the complete chain of unicode decompositions of a character, +rather than stopping after one level, such that searching for +e.g. "GREEK SMALL LETTER IOTA" will now also find "GREEK SMALL LETTER +IOTA WITH OXIA". + ++++ +*** New char-folding options: 'char-fold-include' lets you add ad hoc +foldings, 'char-fold-exclude' to remove foldings from default decomposition, +and 'char-fold-symmetric' to search for any of an equivalence class of +characters. For example, with a nil value of 'char-fold-symmetric' +you can search for "e" to find "é", but not vice versa. With a non-nil +value you can search for either, for example, you can search for "é" +to find "e". + +** Debugger + ++++ +*** The Lisp Debugger is now based on 'backtrace-mode'. +Backtrace mode adds fontification and commands for changing the +appearance of backtrace frames. See the node "(elisp) Backtraces" in +the Elisp manual for documentation of the new mode and its commands. + +** Edebug + ++++ +*** 'edebug-eval-last-sexp' and 'edebug-eval-print-last-sexp' interactively +now take a zero prefix analogously to the non-Edebug counterparts. + ++++ +*** New faces 'edebug-enabled-breakpoint' and 'edebug-disabled-breakpoint'. +When setting breakpoints in Edebug, an overlay with these faces are +placed over the point in question, depending on whether they are +enabled or not. + ++++ +*** New command 'edebug-toggle-disable-breakpoint'. +This command allows you to disable a breakpoint temporarily. This is +mainly useful with breakpoints that are conditional and would take +some time to recreate. + ++++ +*** New command 'edebug-unset-breakpoints'. +To clear all breakpoints in the current form, the 'U' command in +'edebug-mode', or 'M-x edebug-unset-breakpoints' can be used. + +--- +*** Re-instrumenting a function with Edebug will now try to preserve +previously-set breakpoints. However, if the code has changed +substantially, this may not be possible. + ++++ +*** New command 'edebug-remove-instrumentation'. +This command removes Edebug instrumentation from all functions that +have been instrumented. + ++++ +*** The runtime behavior of Edebug's instrumentation can be changed +using the new variables 'edebug-behavior-alist', +'edebug-after-instrumentation-function' and +'edebug-new-definition-function'. Edebug's behavior can be changed +globally or for individual definitions. + ++++ +*** Edebug's backtrace buffer now uses 'backtrace-mode'. +Backtrace mode adds fontification, links and commands for changing the +appearance of backtrace frames. See the node "(elisp) Backtraces" in +the Elisp manual for documentation of the new mode and its commands. + +The binding of 'd' in Edebug's keymap is now 'edebug-pop-to-backtrace' +which replaces 'edebug-backtrace'. Consequently Edebug's backtrace +windows now behave like those of the Lisp Debugger and of ERT, in that +when they appear they will be the selected window. + +The new 'backtrace-goto-source' command, bound to 's', works in +Edebug's backtraces on backtrace frames whose source code has +been instrumented by Edebug. + +** Enhanced xterm support + +--- +*** New user option 'xterm-set-window-title' controls whether Emacs sets +the XTerm window title. This feature is experimental and is disabled +by default. + +** Grep + ++++ +*** 'rgrep', 'lgrep' and 'zrgrep' now hide part of the command line +that contains a list of ignored directories and files. +Clicking on the button with ellipsis unhides it. +The abbreviation can be disabled by the new user option +'grep-find-abbreviate'. The new command +'grep-find-toggle-abbreviation' toggles it interactively. + +--- +*** 'grep-find-use-xargs' is now customizable with sorting options. + +** ERT + ++++ +*** New variable 'ert-quiet' allows making ERT output in batch mode +less verbose by removing non-essential information. + ++++ +*** ERT's backtrace buffer now uses 'backtrace-mode'. +Backtrace mode adds fontification and commands for changing the +appearance of backtrace frames. See the node "(elisp) Backtraces" in +the Elisp manual for documentation of the new mode and its commands. + +** Gamegrid + +--- +*** Gamegrid now determines its default glyph size based on display +dimensions, instead of always using 16 pixels. As a result, Tetris, +Snake and Pong are better playable on HiDPI displays. + +--- +*** 'gamegrid-add-score' can now sort scores from lower to higher. +This is useful for games where lower scores are better, like time-based games. + +** Filecache + +--- +*** Completing file names in the minibuffer via 'C-TAB' now uses the +styles as configured by the user option 'completion-styles'. + +** New macros 'thunk-let' and 'thunk-let*'. +These macros are analogue to 'let' and 'let*', but create bindings that +are evaluated lazily. + +** next-error + ++++ +*** New user option 'next-error-find-buffer-function'. +The value should be a function that determines how to find the +next buffer to be used by 'next-error' and 'previous-error'. The +default is to use the last buffer that navigated to the current +error. + ++++ +*** New command 'next-error-select-buffer'. +It can be used to set any buffer as the next one to be used by +'next-error' and 'previous-error'. + +** nxml-mode + +--- +*** The default value of 'nxml-sexp-element-flag' is now t. +This means that pressing 'C-M-SPACE' now selects the entire tree by +default, and not just the opening element. + +** Eshell + +--- +*** TAB completion uses the standard 'completion-at-point' rather than +'pcomplete'. Its UI is slightly different but can be customized to +behave similarly, e.g. Pcomplete's default cycling can be obtained +with '(setq completion-cycle-threshold 5)'. + +--- +*** 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. + ++++ +*** Expansion of history event designators is disabled by default. +To restore the old behavior, use + + (add-hook 'eshell-expand-input-functions + #'eshell-expand-history-references) + +--- +*** The function 'eshell-uniquify-list' has been renamed from +'eshell-uniqify-list'. + +--- +*** The function 'eshell/kill' is now able to handle signal switches. +Previously 'eshell/kill' would fail if provided a kill signal to send +to the process. It now accepts signals specified either by name or by +its number. + +--- +*** Emacs now follows symlinks in history-related files. +The files specified by 'eshell-history-file-name' and +'eshell-last-dir-ring-file-name' can include symlinks; these are now +followed when Emacs writes the relevant history variables to the disk. + +** Shell + +--- +*** Program name completion inside remote shells works now as expected. + ++++ +*** The user option 'shell-file-name' can be set now as connection-local +variable for remote shells. It still defaults to "/bin/sh". + +** Single shell commands + ++++ +*** 'shell-command-dont-erase-buffer' accepts the value 'erase' to +force to erase the output buffer before execution of the command. + +*** The new functions 'shell-command-save-pos-or-erase' and +'shell-command-set-point-after-cmd' control how point is handled +between two consecutive shell commands in the same buffer. + ++++ +*** 'async-shell-command-width' defines the number of display columns +available for output of asynchronous shell commands. + ++++ +*** Prompt for shell commands can now show the current directory. +Customize the new user option 'shell-command-prompt-show-cwd' to enable it. + +** Pcomplete + +--- +*** The 'pcomplete' command is now obsolete. +The Pcomplete functionality can be obtained via 'completion-at-point' +instead, by adding 'pcomplete-completions-at-point' to +'completion-at-point-functions'. + +--- +*** The function 'pcomplete-uniquify-list' has been renamed from +'pcomplete-uniqify-list'. + +--- +*** 'pcomplete/make' now completes on targets in included files, recursively. +To recover the previous behavior, set new user option +'pcmpl-gnu-makefile-includes' to nil. + +** Auth-source + +--- +*** The Secret Service backend supports the ':create' key now. + +--- +*** ".authinfo" and ".netrc" files now use a new mode: 'authinfo-mode'. +This is just like 'fundamental-mode', except that it hides passwords +under a "****" display property. When the cursor moves to this text, +the real password is revealed (via 'reveal-mode'). The new +'authinfo-hidden' user option can be used to control what to hide. + +** Tramp + ++++ +*** New connection method "nextcloud", which allows accessing OwnCloud +or NextCloud hosted files and directories. + ++++ +*** New connection method "rclone", which allows accessing system +storages via the 'rclone' program. This feature is experimental. + ++++ +*** New connection method "sudoedit", which allows editing local files +with different user credentials. Contrary to the "sudo" method, no +session is run permanently in the background. This is for security +reasons. + ++++ +*** Connection methods "obex" and "synce" have been removed, because they +are obsoleted in GVFS. + ++++ +*** Validated passwords are saved by auth-source backends which support this. + ++++ +*** During user and host name completion in the minibuffer, results +from auth-source search are taken into account. This can be disabled +by setting the user option 'tramp-completion-use-auth-sources' to nil. + ++++ +*** The user option 'tramp-ignored-file-name-regexp' allows disabling +Tramp for some look-alike remote file names. + ++++ +*** For some connection methods, like "su" or "sudo", the host name in +multi-hop file names must match the previous hop. Default host names +are adjusted to the host name from the previous hop. + ++++ +*** A timeout has been added for the connection methods "sudo" and "doas". +The underlying session is disabled when the timeout expires. This is +for security reasons. + ++++ +*** For some connection methods, like "sshx" or "plink", it is +possible to configure the remote login shell. This avoids problems +with remote hosts, where "/bin/sh" is a link to a shell which +cooperates badly with Tramp. + ++++ +*** New commands 'tramp-rename-files' and 'tramp-rename-these-files'. +They allow saving remote files somewhere else when the corresponding +host is not reachable anymore. + +** Rcirc + +--- +*** New user option 'rcirc-url-max-length'. +Setting this option to an integer causes URLs displayed in Rcirc +buffers to be truncated to that many characters. + +--- +*** The default '/quit' and '/part' reasons are now configurable. +Two new user options are provided for this: +'rcirc-default-part-reason' and 'rcirc-default-quit-reason'. + +** Register + +--- +*** The return value of method 'register-val-describe' includes the +names of buffers shown by the windows of a window configuration. + +** Message + +--- +*** Completion of email addresses can use the standard completion UI. +This is controlled by 'message-expand-name-standard-ui'. +With the standard UI the different sources (ecomplete, bbdb, and eudc) +are matched together and try to obey 'completion-styles'. +It should work for other completion front ends like Company. + +--- +*** 'message-mode' now supports highlighting citations of different depths. +This can be customized via the new user option +'message-cite-level-function' and the new 'message-cited-text-*' faces. + ++++ +*** Messages can now be systematically encrypted +when the PGP keyring contains a public key for every recipient. To +achieve this, add 'message-sign-encrypt-if-all-keys-available' to +'message-send-hook'. + +--- +*** When replying a message that have addresses on the form +'"foo@bar.com" <foo@bar.com>', Message will elide the repeated "name" +from the address field in the response. + +--- +*** The default of 'message-forward-as-mime' has changed from t to nil +as it has been reported that many recipients can't read forwards that +are formatted as MIME digests. + ++++ +*** 'message-forward-included-headers' has changed its default to +exclude most headers when forwarding. + +*** 'mml-secure-openpgp-sign-with-sender' sets also "gpg --sender". +When 'mml-secure-openpgp-sign-with-sender' is non-nil message sender's +email address (in addition to its old behavior) will also be used to +set gpg's "--sender email@domain" option. + +The option is useful for two reasons when verifying the signature: + + 1. GnuPG's TOFU statistics are updated for the specific user id + (email) only. See gpg(1) man page about "--sender". + + 2. GnuPG's "--auto-key-retrieve" functionality can use WKD (web key + directory) method for finding the signer's key. You need GnuPG + 2.2.17 to fully benefit from this feature. See gpg(1) man page for + "--auto-key-retrieve". + +--- +** EasyPG + +--- +*** 'epa-pinentry-mode' is renamed to 'epg-pinentry-mode'. +It now applies to epg functions as well as epa functions. + +--- +*** The alias functions 'epa--encode-coding-string', +'epa--decode-coding-string', and 'epa--select-safe-coding-system' have +been removed. Use 'encode-coding-string', 'decode-coding-string', and +'select-safe-coding-system' instead. + +--- +*** 'epg-context' structure supports now 'sender' slot. +The value of the new 'sender' slot (if a string) is used to set gpg's +"--sender" option. This feature is used by +'mml-secure-openpgp-sign-with-sender'. See gpg(1) manual page about +"--sender" for more information. + +--- +** Rmail + ++++ +*** New user option 'rmail-output-reset-deleted-flag'. +If this option is non-nil, messages appended to an output file by the +'rmail-output' command have their Deleted flag reset. + +--- +*** The command 'rmail-summary-by-senders' with an empty argument +selects the messages to summarize with a regexp that matches the +sender of the current message. + +** Threads + ++++ +*** New variable 'main-thread' holds Emacs's main thread. +This is handy in Lisp programs that run on a non-main thread and want +to signal the main thread, e.g., when they encounter an error. + ++++ +*** 'thread-join' now returns the result of the finished thread. + ++++ +*** 'thread-signal' does not propagate errors to the main thread. +Instead, error messages are just printed in the main thread. + +--- +*** 'thread-alive-p' is now obsolete, use 'thread-live-p' instead. + ++++ +*** New command 'list-threads' shows Lisp threads. +See the current list of live threads in a tabulated-list buffer which +automatically updates. In the buffer, you can use 's q' or 's e' to +signal a thread with quit or error respectively, or get a snapshot +backtrace with 'b'. + +** thingatpt.el + +--- +*** 'thing-at-point' supports a new "thing" called 'uuid'. +A symbol 'uuid' can be passed to 'thing-at-point' and it returns the +UUID at point. + +--- +*** 'number-at-point' will now recognize hex numbers like 0xAb09 and #xAb09 +and return them as numbers. + +--- +*** 'word-at-point' and 'sentence-at-point' accept NO-PROPERTIES. +Just like 'thing-at-point' itself. + +** Interactive automatic highlighting + ++++ +*** 'highlight-regexp' can now highlight subexpressions. +The new command accepts a prefix numeric argument to choose the +subexpression. + +** Mouse display of minor mode menu + +--- +*** 'minor-mode-menu-from-indicator' now displays full minor mode name. +When there is no menu for a mode, display the mode name after the +indicator instead of just the indicator (which is sometimes cryptic). + +** rx + +--- +*** rx now handles raw bytes in character alternatives correctly, +when given in a string. Previously, '(any "\x80-\xff")' would match +characters U+0080...U+00FF. Now the expression matches raw bytes in +the 128...255 range, as expected. + +--- +*** The rx 'or' and 'seq' forms no longer require any arguments. +'(or)' produces a regexp that never matches anything, while '(seq)' +matches the empty string, each being an identity for the operation. +This also works for their aliases: '|' for 'or'; ':', 'and' and +'sequence' for 'seq'. +The symbol 'unmatchable' can be used as an alternative to '(or)'. + +--- +*** 'regexp' and new 'literal' accept arbitrary lisp as arguments. +In this case, 'rx' will generate code which produces a regexp string +at run time, instead of a constant string. + +--- +*** New rx extension mechanism: 'rx-define', 'rx-let', 'rx-let-eval'. +These macros add new forms to the rx notation. + ++++ +*** 'anychar' is now an alias for 'anything'. +Both match any single character; 'anychar' is more descriptive. + ++++ +*** New 'intersection' form for character sets. +With 'or' and 'not', it can be used to compose character-matching +expressions from simpler parts. + ++++ +*** 'not' argument can now be a character or single-char string. + +** Frames + ++++ +*** New command 'make-frame-on-monitor' makes a frame on the specified monitor. + ++++ +*** New value of 'minibuffer' frame parameter 'child-frame'. +This allows creating and immediately parenting a minibuffer-only child +frame when making a frame. + +--- +*** New predicates 'display-blink-cursor-p' and 'display-symbol-keys-p'. +These predicates are to be preferred over 'display-graphic-p' when +testing for blinking cursor capability and the capability to have +symbols (e.g., '[return]', '[tab]', '[backspace]') as keys respectively. + +** Tabulated List mode + ++++ +*** New user options for tabulated list sort indicators. +You can now customize which sorting indicator character to display +near the current column in Tabulated Lists (see user options +'tabulated-list-gui-sort-indicator-asc', +'tabulated-list-gui-sort-indicator-desc', +'tabulated-list-tty-sort-indicator-asc', and +'tabulated-list-tty-sort-indicator-desc'). + ++++ +*** Two new commands and keystrokes have been added to the tabulated +list mode: 'w' (which widens the current column) and 'c' which makes +the current column contract. + ++++ +*** New function 'tabulated-list-clear-all-tags'. +This function clears all tags from the padding area in the current +buffer. Tags are typically added by calling 'tabulated-list-put-tag'. + +** Text mode + ++++ +*** 'text-mode-variant' is now obsolete, use 'derived-mode-p' instead. + +** CUA mode + +--- +*** New user option 'cua-rectangle-terminal-modifier-key'. +This user option allows for the customization of the modifier key used +in a terminal frame. + +** JS mode + +--- +*** JSX syntax is now automatically detected and enabled. +If a file imports Facebook's 'React' library, or if the file uses the +extension ".jsx", then various features supporting XML-like syntax +will be supported in 'js-mode' and derivative modes. ('js-jsx-mode' +no longer needs to be enabled.) + +--- +*** New user option 'js-jsx-detect-syntax' disables automatic detection. +This is turned on by default. + +--- +*** New user option 'js-jsx-syntax' enables JSX syntax unconditionally. +This is off by default. + +--- +*** New variable 'js-jsx-regexps' controls JSX detection. + +--- +*** JSX syntax is now highlighted like SGML. + +--- +*** JSX code is properly indented in many more scenarios. +Previously, JSX indentation usually only worked when an element was +wrapped in parenthesis (e.g. in a 'return' statement or a function +call). It would also fail in many intricate cases. Now, indentation +should work anywhere without parenthesis; many more intricacies are +supported; and, indentation conventions align more closely with those +of the React developer community (see 'js-jsx-align->-with-<'), +otherwise still adhering to SGML conventions. + +--- +*** New user option 'js-jsx-align->-with-<' controls '>' indents. +Commonly in JSX code, a '>' on its own line is indented at the same +level as its opening '<'. This is the new default for JSX. This +behavior is slightly different than that used by SGML in Emacs, where +'>' is indented at the same level as attributes, which was also the +old default for JSX. + +This is turned on by default. To get back the old default indentation +behavior of aligning '>' with attributes, set 'js-jsx-align->-with-<' +to nil. + +--- +*** Indentation uses 'js-indent-level' instead of 'sgml-basic-offset'. +Since JSX is a syntax extension of JavaScript, it makes the most sense +for JSX expressions to be indented the same number of spaces as other +JS expressions. This is a breaking change, but it probably aligns +with how you'd expect this indentation to behave. If you want JSX to +be indented like JS, you won't need to change your config. + +The old behavior can be emulated by controlling JSX indentation +independently of JS, by setting 'js-jsx-indent-level'. + +--- +*** New user option 'js-jsx-indent-level' for different JSX indentation. +If you wish to indent JSX by a different number of spaces than JS, set +this user option to the desired number. + +--- +*** New user option 'js-jsx-attribute-offset' for JSX attribute indents. + +--- +*** New variable 'js-syntactic-mode-name' controls mode name display. +Previously, the mode name was simply 'JavaScript'. Now, when a syntax +extension like JSX is enabled, the mode name is 'JavaScript[JSX]'. +Set this variable to nil to disable the new behavior. + +--- +*** New function 'js-use-syntactic-mode-name' for deriving modes. +Packages deriving from 'js-mode' with 'define-derived-mode' should +call this function to add enabled syntax extensions to their mode +name, too. + +** Autorevert + ++++ +*** New user option 'auto-revert-avoid-polling' for saving power. +When set to a non-nil value, buffers in Auto Revert mode are no longer +polled for changes periodically. This reduces the power consumption +of an idle Emacs, but may fail on some network file systems; set +'auto-revert-notify-exclude-dir-regexp' to match files where +notification is not supported. The default value is nil. + ++++ +*** New variable 'buffer-auto-revert-by-notification'. +A major mode can declare that notification on the buffer's default +directory is sufficient to know when updates are required, by setting +the new variable 'buffer-auto-revert-by-notification' to a non-nil +value. Auto Revert mode can use this information to avoid polling the +buffer periodically when 'auto-revert-avoid-polling' is non-nil. + +--- +*** 'global-auto-revert-ignore-buffer' can now also be a predicate +function that can be used for more fine-grained control of which +buffers to auto-revert. + +** auth-source-pass + ++++ +*** New user option 'auth-source-pass-filename'. +Allows setting the path to the password-store, defaults to +"~/.password-store". + ++++ +*** New user option 'auth-source-pass-port-separator'. +Specifies separator between host and port, defaults to colon ":". + +--- +*** Minimize the number of decryptions during password lookup. +This makes the package usable with physical tokens requiring touching +a sensor for every decryption. + +--- +*** 'auth-source-pass-get' is now autoloaded. + +** Bookmarks + +--- +*** 'bookmark-file' and 'bookmark-old-default-file' are now obsolete +aliases of 'bookmark-default-file'. + +--- +*** New user option 'bookmark-watch-bookmark-file'. +When non-nil, watch whether the bookmark file has changed on disk. + +--- +*** The old bookmark file format is no longer supported. +This bookmark file format has not been used in Emacs since at least +version 19.34, released in 1996, and will no longer be automatically +converted to the new bookmark file format. + +The following functions are now declared obsolete: +'bookmark-grok-file-format-version', +'bookmark-maybe-upgrade-file-format', +'bookmark-upgrade-file-format-from-0', and +'bookmark-upgrade-version-0-alist'. + +--- +** The mantemp.el library is now marked obsolete. +This library generates manual C++ template instantiations. It should +no longer be useful on modern compilers, which do this automatically. + +** Ispell + +--- +*** New hook 'ispell-change-dictionary-hook'. +This runs after changing the dictionary and could be used to +automatically spellcheck a buffer when changing language without +needing to advice 'ispell-change-dictionary'. + +** scroll-lock + +--- +*** New command 'scroll-lock-next-line-always-scroll'. +This command is bound to 'S-down' and scrolls the buffer up in +particular when the end of the buffer is visible in the window. + +** mwheel.el + +--- +*** 'mwheel-install' is now obsolete. +Use 'mouse-wheel-mode' instead. Note that 'mouse-wheel-mode' is +already enabled by default on most graphical displays. + +** Gravatar + ++++ +*** 'gravatar-cache-ttl' is now a number of seconds. +The previously used timestamp format of a list of integers is still +supported, but is deprecated. The default value has not changed. + ++++ +*** 'gravatar-size' can now be nil. +This results in the use of Gravatar's default size of 80 pixels. + ++++ +*** The default fallback gravatar is now configurable. +This is possible using the new user options 'gravatar-default-image' +and 'gravatar-force-default'. + +** ada-mode + +--- +*** The built-in ada-mode is now deleted. The GNU ELPA package is a +good replacement, even in very large source files. + +** time-stamp + +--- +*** New '%5z' conversion for 'time-stamp-format' gives time zone offset. +Specifying '%5z' in 'time-stamp-format' or 'time-stamp-pattern' +expands to the time zone offset, e.g., '+0100'. The time zone used is +specified by 'time-stamp-time-zone'. + +Because this feature is new in Emacs 27.1, do not use it in the local +variables section of any file that might be edited by an older version +of Emacs. + +--- +*** Some conversions recommended for 'time-stamp-format' have changed. +The new documented/recommended %-conversions are closer to those +used by 'format-time-string' and are compatible at least as far back +as Emacs 22.1 (released in 2007). + +Uppercase abbreviated day name of week: was %3A, now %#a +Full day name of week: was %:a, now %:A +Uppercase abbreviated month name: was %3B, now %#b +Full month name: was %:b, now %:B +Four-digit year: was %:y, now %Y +Lowercase timezone name: was %z, now %#Z +Fully-qualified host name: was %s, now %Q +Unqualified host name: (was none), now %q +Login name: was %u, now %l +User's full name: was %U, now %L + +Merely having '(add-hook 'before-save-hook 'time-stamp)' in your +Emacs init file does not expose you to this change. However, +if you set 'time-stamp-format' or 'time-stamp-pattern' with a +file-local variable, you may need to update the value. + +** mode-local + +--- +*** Declare 'define-overload' and 'define-child-mode' as obsolete. + +--- +*** Rename several internal functions to use a 'mode-local-' prefix. + +** CC Mode + ++++ +*** You can now flag "wrong style" comments with 'font-lock-warning-face'. +To do this, use 'c-toggle-comment-style', if needed, to set the desired +default comment style (block or line); then set the user option +'c-mark-wrong-style-of-comment' to non-nil. + +** Mailcap + +--- +*** The new function 'mailcap-file-name-to-mime-type' has been added. +It's a simple convenience function for looking up MIME types based on +file name extensions. + +--- +*** The default way the list of possible external viewers for MIME +types is sorted and chosen has changed. Earlier, the most specific +viewer was chosen, even if there was a general override in "~/.mailcap". +For instance, if "/etc/mailcap" has an entry for "image/gif", that one +will be chosen even if you have an entry for "image/*" in your +"~/.mailcap" file. But with the new method, entries from "~/.mailcap" +overrides all system and Emacs-provided defaults. To get the old +method back, set 'mailcap-prefer-mailcap-viewers' to nil. + +** MH-E ++++ +*** The hook 'mh-show-mode-hook' is now called before the message is inserted. +Functions that want to affect the message text (for example, to change +highlighting) can no longer use 'mh-show-mode-hook', because the +message contents will not yet have been inserted when the hook is +called. Such functions should now be attached to 'mh-show-hook'. + +** URL + +--- +*** The 'file:' handler no longer looks for "index.html" in +directories if you ask it for a "file:///dir" URL. Since this is a +low-level library, such decisions (if they are to be made at all) are +left to higher-level functions. + + +* New Modes and Packages in Emacs 27.1 + +** Tab Bars + ++++ +*** Tab Bar mode +The new command 'tab-bar-mode' enables the tab bar at the top of each +frame, where you can use tabs to switch between named persistent +window configurations. + +The 'C-x t' sequence is the new prefix key for tab-related commands: +'C-x t 2' creates a new tab; 'C-x t 0' deletes the current tab; +'C-x t b' switches to buffer in another tab; 'C-x t f' and 'C-x t C-f' +edit file in another tab; and 'C-TAB' and 'S-C-TAB' switch to the next +or previous tab. You can also switch between tabs and create/delete +tabs with a mouse. + +Tab-related commands are available even when 'tab-bar-mode' is +disabled: by default, they enable 'tab-bar-mode' in that case. + +The X resource "tabBar", class "TabBar" enables the tab bar +when its value is "on", "yes" or "1". + +The user option 'tab-bar-position' specifies where to show the tab bar. + +Read the new Info node "(emacs) Tab Bars" for full description +of all related features. + ++++ +*** Tab Line mode +The new command 'global-tab-line-mode' enables the tab line above each +window, which you can use to switch buffers in the window. Selecting +the previous window-local tab is the same as typing 'C-x <LEFT>' +('previous-buffer'), selecting the next tab is the same as 'C-x <RIGHT>' +('next-buffer'). Both commands support a numeric prefix argument as +a repeat count. Clicking on the plus icon adds a new buffer to the +window-local tab line of buffers. Using the mouse wheel on the tab +line scrolls tabs. + ++++ +** fileloop.el lets one setup multifile operations like search&replace. + ++++ +** Emacs can now visit files in archives as if they were directories. +This feature uses Tramp and works only on systems which support GVFS, +i.e. GNU/Linux, roughly spoken. See the node "(tramp) Archive file +names" in the Tramp manual for full documentation of these facilities. + ++++ +** New library for writing JSONRPC applications (https://jsonrpc.org). +The 'jsonrpc' library enables writing Emacs Lisp applications that +rely on this protocol. Since the protocol is designed to be +transport-agnostic, the library provides an API to implement new +transport strategies as well as a separate API to use them. A +transport implementation for process-based communication, such as is +used by the Language Server Protocol (LSP), is readily available. + ++++ +** Backtrace mode improves viewing of Elisp backtraces. +Backtrace mode adds pretty printing, fontification and ellipsis +expansion to backtrace buffers produced by the Lisp debugger, Edebug +and ERT. See the node "(elisp) Backtraces" in the Elisp manual for +documentation of the new mode and its commands. + ++++ +** so-long.el helps to mitigate performance problems with long lines. +When 'global-so-long-mode' has been enabled, visiting a file with very +long lines will (subject to configuration) cause the user's preferred +'so-long-action' to be automatically invoked (by default, the buffer's +major mode is replaced by 'so-long-mode'). In extreme cases this can +prevent delays of several minutes, and make Emacs responsive almost +immediately. Type 'M-x so-long-commentary' for full documentation. + + +* Incompatible Lisp Changes in Emacs 27.1 + +--- +** Incomplete destructive splicing support has been removed. +Support for Common Lisp style destructive splicing (",.") was +incomplete and broken for a long time. It has now been removed. + +This means that backquote substitution now works for identifiers +starting with a period ("."). Consider the following example: + + (let ((.foo 42)) `,.foo) + +In the past, this would have incorrectly evaluated to '(\,\. foo)', +but will now instead evaluate to '42'. + +--- +** The REGEXP in 'magic-mode-alist' is now matched case-sensitively. +Likewise for 'magic-fallback-mode-alist'. + ++++ +** 'add-hook' does not always add to the front or the end any more. +The replacement of 'append' with 'depth' implies that the function is +not always added to the very front (when append/depth is nil) or the +very end (when append/depth is t) any more because other functions on +the hook may have specified higher/lower depths. This makes it +possible to control the ordering of functions more precisely, as was +already possible in 'add-function' and 'advice-add'. + +--- +** In 'compilation-error-regexp-alist' the old undocumented feature +where 'line' could be a function of 2 arguments has been dropped. + +--- +** 'define-fringe-bitmap' is always defined, even when Emacs is built +without any GUI support. + +--- +** Just loading a theme's file no longer activates the theme's settings. +Loading a theme with 'M-x load-theme' still activates the theme, as it +did before. However, loading the theme's file with 'M-x load-file', +or using 'require' or 'load' in a Lisp program, doesn't actually apply +the theme's settings until you either invoke 'M-x enable-theme' or +type 'M-x load-theme'. (In a Lisp program, calling 'enable-theme' or +invoking 'load-theme' with NO-ENABLE argument omitted or nil has the +same effect of activating a theme whose file has been loaded.) The +special case of the 'user' theme is an exception: it is frequently +used for ad-hoc customizations, so the settings of that theme are by +default applied immediately. + +The variable 'custom--inhibit-theme-enable' controls this behavior; +its default value changed in Emacs 27.1. + +--- +** The REPETITIONS argument of 'benchmark-run' can now also be a variable. + +--- +** Interpretation of relative 'HOME' directory has changed. +If "$HOME" is set to a relative file name, 'expand-file-name' now +interprets it relative to the directory where Emacs was started, not +relative to the 'default-directory' of the current buffer. We recommend +always setting "$HOME" to an absolute file name, so that its meaning is +independent of where Emacs was started. + +--- +** 'file-name-absolute-p' no longer considers "~foo" to be an absolute +file name if there is no user named "foo". + ++++ +** The FILENAME argument to 'file-name-base' is now mandatory and no +longer defaults to 'buffer-file-name'. + ++++ +** File metadata primitives now signal an error if I/O, access, or +other serious errors prevent them from determining the result. +Formerly, these functions often (though not always) silently returned +nil. For example, if there is an access error, I/O error or low-level +integer overflow when getting the attributes of a file F, +'(file-attributes F)' now signals an error instead of returning nil. +These functions still behave as before if the only problem is that the +file does not exist. The affected primitives are +'directory-files-and-attributes', 'file-acl', 'file-attributes', +'file-modes', 'file-newer-than-file-p', 'file-selinux-context', +'file-system-info', and 'set-visited-file-modtime'. + +--- +** 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. + +--- +** Old-style backquotes now generate an error. +They have been generating warnings for a decade. To interpret +old-style backquotes as new-style, bind the new variable +'force-new-style-backquotes' to t. + +--- +** Defining a Common Lisp structure using 'cl-defstruct' or +'cl-struct-define' whose name clashes with a builtin type (e.g., +'integer' or 'hash-table') now signals an error. + +--- +** When formatting a floating-point number as an octal or hexadecimal +integer, Emacs now signals an error if the number is too large for the +implementation to format. + ++++ +** 'logb' now returns infinity when given an infinite or zero argument, +and returns a NaN when given a NaN. Formerly, it returned an extreme +fixnum for such arguments. + +--- +** Some functions and variables obsolete since Emacs 22 have been removed: +'archive-mouse-extract', 'assoc-ignore-case', 'assoc-ignore-representation', +'backward-text-line', 'blink-cursor', 'bookmark-exit-hooks', +'c-opt-op-identitier-prefix', 'comint-use-prompt-regexp-instead-of-fields', +'compilation-finish-function', 'count-text-lines', 'cperl-vc-header-alist', +'custom-face-save-command', 'cvs-display-full-path', 'cvs-fileinfo->full-path', +'delete-frame-hook', 'derived-mode-class', 'describe-char-after', +'describe-project', 'desktop-basefilename', 'desktop-buffer-handlers', +'desktop-buffer-misc-functions', 'desktop-buffer-modes-to-save', +'desktop-enable', 'desktop-load-default', 'dired-omit-files-p', +'disabled-command-hook', 'dungeon-mode-map', 'electric-nroff-mode', +'electric-nroff-newline', 'electric-perl-terminator', 'focus-frame', +'forward-text-line', 'generic-define-mswindows-modes', +'generic-define-unix-modes', 'generic-font-lock-defaults', +'goto-address-at-mouse', 'highlight-changes-colours', +'ibuffer-elide-long-columns', 'ibuffer-hooks', 'ibuffer-mode-hooks', +'icalendar-convert-diary-to-ical', 'icalendar-extract-ical-from-buffer', +'imenu-always-use-completion-buffer-p', 'ipconfig-program', +'ipconfig-program-options', 'isearch-lazy-highlight-cleanup', +'isearch-lazy-highlight-initial-delay', 'isearch-lazy-highlight-interval', +'isearch-lazy-highlight-max-at-a-time', 'iswitchb-use-fonts', +'latin1-char-displayable-p', 'mouse-wheel-click-button', +'mouse-wheel-down-button', 'mouse-wheel-up-button', 'new-frame', +'pascal-outline', 'process-kill-without-query', +'recentf-menu-append-commands-p', 'rmail-pop-password', +'rmail-pop-password-required', 'savehist-load', 'set-default-font', +'spam-list-of-processors', 'speedbar-add-ignored-path-regexp', +'speedbar-buffers-line-path', 'speedbar-ignored-path-expressions', +'speedbar-ignored-path-regexp', 'speedbar-line-path', 'speedbar-path-line', +'timer-set-time-with-usecs', 'tooltip-gud-display', 'tooltip-gud-modes', +'tooltip-gud-toggle-dereference', 'unfocus-frame', 'unload-hook-features-list', +'update-autoloads-from-directories', 'vc-comment-ring', 'vc-comment-ring-index', +'vc-comment-search-forward', 'vc-comment-search-reverse', +'vc-comment-to-change-log', 'vc-diff-switches-list', 'vc-next-comment', +'vc-previous-comment', 'view-todo', 'x-lost-selection-hooks', +'x-sent-selection-hooks'. + +--- +** Further functions and variables obsolete since Emacs 24 have been removed: +'default-directory-alist', 'dired-default-directory', +'dired-default-directory-alist', 'dired-enable-local-variables', +'dired-hack-local-variables', 'dired-local-variables-file', +'dired-omit-here-always'. + ++++ +** Garbage collection no longer treats miscellaneous objects specially; +they are now allocated like any other pseudovector. As a result, the +'garbage-collect' and 'memory-use-count' functions no longer return a +'misc' component, and the 'misc-objects-consed' variable has been +removed. + ++++ +** Reversed character ranges are no longer permitted in 'rx'. +Previously, ranges where the starting character is greater than the +ending character were silently omitted. +For example, '(rx (any "@z-a" (?9 . ?0)))' would match '@' only. +Now, such 'rx' expressions generate an error. + +--- +** Internal 'rx' functions and variables have been removed, +as a consequence of an improved implementation. Packages using +these should use the public 'rx' and 'rx-to-string' instead. +'rx-constituents' is still available for compatibility, but the new +extension mechanism is preferred: 'rx-define', 'rx-let' and +'rx-let-eval'. + ++++ +** 'text-mode' no longer sets the value of 'indent-line-function'. +The global value of 'indent-line-function', which defaults to +'indent-relative', will no longer be reset locally when turning on +'text-mode'. + +To get back the old behavior, add a function to 'text-mode-hook' which +performs '(setq-local indent-line-function #'indent-relative)'. + +--- +** 'make-process' no longer accepts a non-nil ':stop' key. This has +never worked reliably, and now causes an error. + ++++ +** 'eventp' no longer returns non-nil for lists whose car is nil. +This is consistent with the fact that nil, though a symbol, is not a +valid event type. + +--- +** The obsolete package xesam.el (since Emacs 24) has been removed. + ++++ +** The XBM image handler now accepts a ':stride' argument, which should +be specified in image specs representing the entire bitmap as a single +bool vector. + ++++ +** 'regexp-quote' may return its argument string. +If the argument needs no quoting, it can be returned instead of a copy. + ++++ +** Mouse scroll up and down with control key modifier changes font size. +Previously, the control key modifier was used to scroll up or down by +an amount which was close to near a full screen. This is now instead +available by scrolling with the meta modifier key. + +To get the old behavior back, customize the user option +'mouse-wheel-scroll-amount', or add the following to your init file: + +(customize-set-variable 'mouse-wheel-scroll-amount + '(5 ((shift) . 1) ((control) . nil))) + +By default, the font size will be changed in the window that the mouse +pointer is over. To change this behavior, you can customize the user +option 'mouse-wheel-follow-mouse'. Note that this will also affect +scrolling. + ++++ +** Mouse scroll up and down with control key modifier also works on images +where it scales the image under the mouse pointer. + +--- +** 'help-follow-symbol' now signals 'user-error' if point (or the +position pointed to by the argument POS) is not in a symbol. + +--- +** The options.el library has been removed. +It was obsolete since Emacs 22.1, replaced by customize. + +--- +** The tls.el and starttls.el libraries are now marked obsolete. +Use of built-in libgnutls based functionality (described in the Emacs +GnuTLS manual) is recommended instead. + +--- +** The url-ns.el library is now marked obsolete. +This library is used to open configuration files for the long defunct +web browser Netscape, and is no longer relevant. + + +* Lisp Changes in Emacs 27.1 + ++++ +** Emacs Lisp integers can now be of arbitrary size. +Emacs uses the GNU Multiple Precision (GMP) library to support +integers whose size is too large to support natively. The integers +supported natively are known as "fixnums", while the larger ones are +"bignums". The new predicates 'bignump' and 'fixnump' can be used to +distinguish between these two types of integers. + +All the arithmetic, comparison, and logical (a.k.a. "bitwise") +operations where bignums make sense now support both fixnums and +bignums. However, note that unlike fixnums, bignums will not compare +equal with 'eq', you must use 'eql' instead. (Numerical comparison +with '=' works on both, of course.) + +Since large bignums consume a lot of memory, Emacs limits the size of +the largest bignum a Lisp program is allowed to create. The +nonnegative value of the new variable 'integer-width' specifies the +maximum number of bits allowed in a bignum. Emacs signals an integer +overflow error if this limit is exceeded. + +Several primitive functions formerly returned floats or lists of +integers to represent integers that did not fit into fixnums. These +functions now simply return integers instead. Affected functions +include functions like 'encode-char' that compute code-points, functions +like 'file-attributes' that compute file sizes and other attributes, +functions like 'process-id' that compute process IDs, and functions like +'user-uid' and 'group-gid' that compute user and group IDs. + ++++ +** 'overflow-error' is now documented as a subcategory of 'range-error'. +Formerly it was undocumented, and was (incorrectly) a subcategory +of 'domain-error'. + +** Time values + ++++ +*** New function 'time-convert' converts Lisp time values to Lisp +timestamps of various forms, including a new timestamp form '(TICKS +. HZ)' where TICKS is an integer and HZ a positive integer denoting a +clock frequency. + ++++ +*** Although the default timestamp format is still '(HI LO US PS)', +it is planned to change in a future Emacs version, to exploit bignums. +The documentation has been updated to mention that the timestamp +format may change and that programs should use functions like +'format-time-string', 'decode-time', and 'time-convert' rather than +probing the innards of a timestamp directly, or creating a timestamp +by hand. + ++++ +*** Decoded (calendrical) timestamps now have subsecond resolution. +This affects 'decode-time', which generates these timestamps, as well +as functions like 'encode-time' that accept them. The subsecond info +is present as a '(TICKS . HZ)' value in the seconds element of a +decoded timestamp, and 'decode-time' has a new optional FORM argument +specifying the form of the seconds member. For example, if X is the +timestamp '(1566009571321878186 . 1000000000)', which represents +"2019-08-17 02:39:31.321878186 UTC", '(decode-time X t t)' returns +'((31321878186 . 1000000000) 39 2 17 8 2019 6 nil 0)' instead of the +traditional '(31 39 2 17 8 2019 6 nil 0)' returned by plain +'(decode-time X t)'. Although the default FORM is currently +'integer', which truncates the seconds to an integer and is the +traditional behavior, this default may change in future Emacs +versions, so callers requiring an integer should specify FORM +explicitly. + ++++ +*** 'encode-time' supports a new API '(encode-time TIME)'. +The old 'encode-time' API is still supported. + ++++ +*** A new package to parse ISO 8601 time, date, durations and +intervals has been added. The main function to use is +'iso8601-parse', but there's also 'iso8601-parse-date', +'iso8601-parse-time', 'iso8601-parse-duration' and +'iso8601-parse-interval'. All these functions return decoded time +structures, except the final one, which returns three of them (start, +end and duration). + ++++ +*** 'time-add', 'time-subtract', and 'time-less-p' now accept +infinities and NaNs too, and propagate them or return nil like +floating-point operators do. If both arguments are finite, these +functions now return exact results instead of rounding in some cases, +and they also avoid excess precision when that is easy. + ++++ +*** New function 'time-equal-p' compares time values for equality. + ++++ +*** 'format-time-string' supports a new conversion specifier flag '+' +that acts like the '0' flag but also puts a '+' before nonnegative +years containing more than four digits. This is for compatibility +with POSIX.1-2017. + ++++ +*** To access (or alter) the elements of a decoded time value, the +'decoded-time-second', 'decoded-time-minute', 'decoded-time-hour', +'decoded-time-day', 'decoded-time-month', 'decoded-time-year', +'decoded-time-weekday', 'decoded-time-dst' and 'decoded-time-zone' +accessors can be used. + +*** The new functions 'date-days-in-month' (which will say how many +days there are in a month in a specific year), 'date-ordinal-to-time' +(that computes the date of an ordinal day), 'decoded-time-add' (for +doing computations on a decoded time structure), 'make-decoded-time' +(for making a decoded time structure with only the given keywords +filled out), and 'encoded-time-set-defaults' (which fills in nil +elements as if it's midnight January 1st, 1970) have been added. + ++++ +*** In the DST slot, 'encode-time' and 'parse-time-string' now return -1 +if it is not known whether daylight saving time is in effect. +Formerly they were inconsistent: 'encode-time' returned t in this +situation, whereas 'parse-time-string' returned nil. Now they +consistently use nil to mean that DST is not in effect, and use -1 +to mean that it is not known whether DST is in effect. + ++++ +** New macro 'benchmark-progn'. +This macro works like 'progn', but messages how long it takes to +evaluate the body forms. The value of the last form is the return +value. + ++++ +** New function 'read-char-from-minibuffer'. +This function works like 'read-char', but uses 'read-from-minibuffer' +to read a character, so it maintains a history that can be navigated +via usual minibuffer keystrokes 'M-p'/'M-n'. + +--- +** New variables 'set-message-function' and 'clear-message-function' +can be used to specify functions to show and clear messages that +normally are displayed in the echo area. + ++++ +** 'setq-local' can now set an arbitrary number of variables, which +makes the syntax more like 'setq'. + +--- +** 'reveal-mode' can now also be used for more than to toggle between +invisible and visible: It can also toggle 'display' properties in +overlays. This is only done on 'display' properties that have the +'reveal-toggle-invisible' property set. + ++++ +** 'process-contact' now takes an optional NO-BLOCK argument to allow +not waiting for a process to be set up. + +--- +** New variable 'read-process-output-max' controls sub-process throughput. +This variable determines how many bytes can be read from a sub-process +in one read operation. The default, 4096 bytes, was previously a +hard-coded constant. Setting it to a larger value might enhance +throughput of reading from sub-processes that produces vast +(megabytes) amounts of data in one go. + ++++ +** The new user option 'quit-window-hook' is now run first when +executing the 'quit-window' command. + +** The user options 'help-enable-completion-auto-load', +'help-enable-auto-load' and 'vhdl-project-auto-load', as well as the +function 'vhdl-auto-load-project' have been renamed to have "autoload" +without the hyphen in their names. Obsolete aliases from the old +names have been added. + ++++ +** Buttons (created with 'make-button' and related functions) can +now use the 'button-data' property. If present, the data in this +property will be passed on to the 'action' function instead of the +button itself in 'button-activate'. + ++++ +** 'defcustom' now takes a ':local' keyword that can be either t or +'permanent', which mean that the variable should be automatically +buffer-local. 'permanent' also sets the variable's 'permanent-local' +property. + ++++ +** The new macro 'with-suppressed-warnings' can be used to suppress +specific byte-compile warnings. + ++++ +** The new macro 'ignore-error' is like 'ignore-errors', but takes a +specific error condition, and will only ignore that condition. (This +can also be a list of conditions.) + +--- +** The new function 'byte-compile-info-message' can be used to output +informational messages that look pleasing during the Emacs build. + +--- +** New 'help-fns-describe-variable-functions' hook. +It makes it possible to add metadata information to 'describe-variable'. + +** i18n (internationalization) + +--- +*** 'ngettext' can be used now to return the right plural form +according to the given numeric value. + ++++ +** 'inhibit-null-byte-detection' is renamed to 'inhibit-nul-byte-detection'. + ++++ +** 'self-insert-command' takes the char to insert as (optional) argument. + ++++ +** 'lookup-key' can take a list of keymaps as argument. + ++++ +** 'condition-case' now accepts t to match any error symbol. + ++++ +** New function 'proper-list-p'. +Given a proper list as argument, this predicate returns its length; +otherwise, it returns nil. 'format-proper-list-p' is now an obsolete +alias for the new function. + +--- +** 'define-minor-mode' automatically documents the meaning of ARG. + ++++ +** The function 'recenter' now accepts an additional optional argument. +By default, calling 'recenter' will not redraw the frame even if +'recenter-redisplay' is non-nil. Call 'recenter' with the new second +argument non-nil to force redisplay per 'recenter-redisplay's value. + ++++ +** New functions 'major-mode-suspend' and 'major-mode-restore'. +Use them when switching temporarily to another major mode, e.g. for +'hexl-mode', or to switch between 'c-mode' and 'image-mode' in XPM. + ++++ +** New macro 'dolist-with-progress-reporter'. +This works like 'dolist', but reports progress similar to +'dotimes-with-progress-reporter'. + ++++ +** New hook 'after-delete-frame-functions'. +This works like 'delete-frame-functions', but runs after the frame to +be deleted has been made dead and removed from the frame list. + +--- +** The function 'provided-mode-derived-p' was extended to support aliases. +The function now returns non-nil when the argument MODE is derived +from any alias of any of MODES. + ++++ +** New frame focus state inspection interface. +The hooks 'focus-in-hook' and 'focus-out-hook' are now obsolete. +Instead, attach to 'after-focus-change-function' using 'add-function' +and inspect the focus state of each frame using 'frame-focus-state'. + ++++ +** Emacs now requests and recognizes focus-change notifications from TTYs. +On terminal emulators that support the feature, Emacs can now support +'focus-in-hook' and 'focus-out-hook' for TTY frames. + ++++ +** Window-specific face remapping. +Face specifications (of the kind used in 'face-remapping-alist') +now support filters, allowing faces to vary between different windows +displaying the same buffer. See the node "(elisp) Face Remapping" +of the Emacs Lisp Reference manual for more detail. + ++++ +** Window change functions have been redesigned. +Hooks reacting to window changes run now only when redisplay detects +that a change has actually occurred. Six hooks are now provided: +'window-buffer-change-functions' (run after window buffers have +changed), 'window-size-change-functions' (run after a window was +assigned a new buffer or size), 'window-configuration-change-hook' +(like the former but run also when a window was deleted), +'window-selection-change-functions' (run when the selected window +changed) and 'window-state-change-functions' and +'window-state-change-hook' (run when any of the preceding ones is +run). Applications can enforce running the latter two using the new +function 'set-frame-window-state-change'. 'window-scroll-functions' +are unaffected by these changes. + +In addition, a number of functions now allow the caller to detect what +has changed since last redisplay: 'window-old-buffer' returns for any +window the buffer it showed at that time. 'old-selected-window' and +'old-selected-frame' return the window and frame that were selected +during last redisplay. 'window-old-pixel-width' (renamed from +'window-pixel-width-before-size-change'), 'window-old-pixel-height' +(renamed from 'window-pixel-height-before-size-change'), +'window-old-body-pixel-width' and 'window-old-body-pixel-height' +return the total and body sizes of any window during last redisplay. + +Also 'run-window-configuration-change-hook' is declared obsolete. + +See the section "(elisp) Window Hooks" in the Elisp manual for a +detailed explanation of the new behavior. + ++++ +** Scroll bar and fringe settings can now be made persistent for windows. +The functions 'set-window-scroll-bars' and 'set-window-fringes' now +have a new optional argument that makes the settings they produce +reliably survive subsequent invocations of 'set-window-buffer'. + ++++ +** New user option 'resize-mini-frames'. +This option allows automatically resizing minibuffer-only frames +similarly to how minibuffer windows are resized on "normal" frames. + ++++ +** New buffer display action function 'display-buffer-in-direction'. +This function allows specifying the location of the window chosen by +'display-buffer' in various ways. + ++++ +** New buffer display action alist entry 'dedicated'. +Such an entry allows specifying the dedicated status of a window +created by 'display-buffer'. + ++++ +** New buffer display action alist entry 'window-min-height'. +Such an entry allows specifying a minimum height of the window used +for displaying a buffer. 'display-buffer-below-selected' is the only +action function to respect it at the moment. + ++++ +** New buffer display action alist entry 'direction'. +This entry is used to specify the location of the window chosen by +'display-buffer-in-direction'. + ++++ +** Additional meaning of display action alist entry 'window'. +A 'window' entry can now also specify a reference window for +'display-buffer-in-direction'. + ++++ +** The function 'assoc-delete-all' now takes an optional predicate argument. + ++++ +** New function 'string-distance' to calculate the Levenshtein distance +between two strings. + ++++ +** 'print-quoted' now defaults to t, so if you want to see +'(quote x)' instead of 'x you will have to bind it to nil where applicable. + ++++ +** Numbers formatted via '%o' or '%x' are now formatted as signed integers. +This avoids problems in calls like '(read (format "#x%x" -1))', and is +more compatible with bignums. To get the traditional machine-dependent +behavior, set the experimental variable 'binary-as-unsigned' to t, +and if the new behavior breaks your code please email +<32252@debbugs.gnu.org>. Because '%o' and '%x' can now format signed +integers, they now support the '+' and space flags. + ++++ +** In Emacs Lisp mode, symbols with confusable quotes are highlighted. +For example, the first character in '‘foo' would be highlighted in +'font-lock-warning-face'. + ++++ +** Omitting variables after '&optional' and '&rest' is now allowed. +For example '(defun foo (&optional))' is no longer an error. This is +sometimes convenient when writing macros. See the ChangeLog entry +titled "Allow '&rest' or '&optional' without following variable +(Bug#29165)" for a full listing of which arglists are accepted across +versions. + +--- +** Internal parsing commands now use 'syntax-ppss' and disregard +'open-paren-in-column-0-is-defun-start'. This affects mostly things like +'forward-comment', 'scan-sexps', and 'forward-sexp' when parsing backward. +The new variable 'comment-use-syntax-ppss' can be set to nil to recover +the old behavior if needed. +This also means that there is no longer any need to precede opening +brackets at the start of a line inside documentation strings with a +backslash, although there is no harm in doing so to make the code +easier to edit with an older Emacs version. + +--- +** The 'server-name' and 'server-socket-dir' variables are set when a +socket has been passed to Emacs. + +--- +** The 'file-system-info' function is now available on all platforms. +instead of just Microsoft platforms. This fixes a 'get-free-disk-space' +bug on OS X 10.8 and later. + +--- +** The function 'get-free-disk-space' returns now a non-nil value for +remote systems, which support this check. + ++++ +** 'memory-limit' now returns a better estimate of memory consumption. + ++++ +** When interpreting 'gc-cons-percentage', Emacs now estimates the +heap size more often and (we hope) more accurately. E.g., formerly +'(progn (let ((gc-cons-percentage 0.8)) BODY1) BODY2)' continued to use +the 0.8 value during BODY2 until the next garbage collection, but that +is no longer true. Applications may need to re-tune their GC tricks. + ++++ +** New macro 'combine-change-calls' arranges to call the change hooks +('before-change-functions' and 'after-change-functions') just once +each around a sequence of lisp forms, given a region. This is +useful when a function makes a possibly large number of repetitive +changes and the change hooks are time consuming. + ++++ +** 'eql', 'make-hash-table', etc. now treat NaNs consistently. +Formerly, some of these functions ignored signs and significands of +NaNs. Now, all these functions treat NaN signs and significands as +significant. For example, '(eql 0.0e+NaN -0.0e+NaN)' now returns nil +because the two NaNs have different signs; formerly it returned t. +Also, Emacs now reads and prints NaN significands; e.g., if X is a +NaN, '(format "%s" X)' now returns "0.0e+NaN", "1.0e+NaN", etc., +depending on X's significand. + ++++ +** The function 'make-string' accepts an additional optional argument. +If the optional third argument is non-nil, 'make-string' will produce +a multibyte string even if its second argument is an ASCII character. + +--- +** '(format "%d" X)' no longer mishandles a floating-point number X that +does not fit in a machine integer. + +--- +** New coding-system 'ibm038'. +This is the International EBCDIC encoding, also available as aliases +'ebcdic-int' and 'cp038'. + +--- +** New JSON parsing and serialization functions 'json-serialize', +'json-insert', 'json-parse-string', and 'json-parse-buffer'. These +are implemented in C using the Jansson library. + ++++ +** New function 'ring-resize'. +'ring-resize' can be used to grow or shrink a ring. + ++++ +** New function 'flatten-tree'. +'flatten-list' is provided as an alias. These functions take a tree +and 'flatten' it such that the result is a list of all the terminal +nodes. + ++++ +** 'zlib-decompress-region' can partially decompress corrupted data. +If the new optional ALLOW-PARTIAL argument is passed, then the data +that was decompressed successfully before failing will be inserted +into the buffer. + +** Image mode + +--- +*** New library Exif. +An Exif library has been added that can parse JPEG files and output +data about creation times and orientation and the like. +'exif-parse-file' and 'exif-parse-buffer' are the main interface +functions. + +--- +*** 'image-mode' now uses this library to automatically rotate images +according to the orientation in the Exif data, if any. + +--- +*** New library image-converter. +If you need to view exotic image formats for which Emacs doesn't have +native support, customize the new user option +'image-use-external-converter' to t. If your system has +GraphicsMagick, ImageMagick or 'ffmpeg' installed, they will then be +used to convert images automatically before displaying them. + +--- +*** 'auto-mode-alist' now includes many of the types typically +supported by the external image converters, like WEPB, BMP and ICO. +These now default to using 'image-mode'. + +--- +*** 'imagemagick-types-inhibit' disables using ImageMagick by default. +'image-mode' started using ImageMagick by default for all images +some years back. It now respects 'imagemagick-types-inhibit' as a way +to disable that. + +--- +*** Some 'image-mode' variables are now buffer-local. +The image parameters 'image-transform-rotation', +'image-transform-scale' and 'image-transform-resize' are now declared +buffer-local, so each buffer could have its own values for these +parameters. + ++++ +*** Three new 'image-mode' commands have been added: 'm', which marks +the file in the dired buffer(s) for the directory the file is in; 'u', +which unmarks the file; and 'w', which pushes the current buffer's file +name to the kill ring. + ++++ +*** The command 'image-rotate' now accepts a prefix argument. +With a prefix argument, 'image-rotate' now rotates the image at point +90 degrees counter-clockwise, instead of the default clockwise. + +** Modules + +--- +*** The function 'load' now behaves correctly when loading modules. +Specifically, it puts the module name into 'load-history', prints +loading messages if requested, and protects against recursive loads. + ++++ +*** New module environment function 'process_input' to process user +input while module code is running. + ++++ +*** New module environment functions 'make_time' and 'extract_time' to +convert between timespec structures and Emacs Lisp time values. + ++++ +*** New module environment functions 'make_big_integer' and +'extract_big_integer' to create and extract arbitrary-size integer +values. + ++++ +*** emacs-module.h now defines a macro 'EMACS_MAJOR_VERSION' that expands +to the major version of the latest Emacs supported by the header. + ++++ +** The function 'read-variable' now uses its own history list. +The history of variable names read by 'read-variable' is recorded in +the new variable 'custom-variable-history'. + +--- +** The functions 'string-to-unibyte' and 'string-to-multibyte' are no +longer declared obsolete. We have found that there are legitimate use +cases for these functions, where there's no better alternative. We +believe that the incorrect uses of these functions all but disappeared +by now, so we are un-obsoleting them. + ++++ +** New function 'group-name' returns a group name corresponding to GID. + ++++ +** 'make-process' now takes a keyword argument ':file-handler'; if +that is non-nil, it will look for a file name handler for the current +buffer's 'default-directory' and invoke that file name handler to make +the process. That way 'make-process' can start remote processes. + ++++ +** '(locale-info 'paper)' now returns the paper size on systems that support it. +This is currently supported on GNUish hosts and on modern versions of +MS-Windows. + ++++ +** The function 'regexp-opt', when given an empty list of strings, now +returns a regexp that never matches anything, which is an identity for +this operation. Previously, the empty string was returned in this +case. + ++++ +** New constant 'regexp-unmatchable' contains a never-matching regexp. +It is a convenient and readable way to specify a regexp that should +not match anything, and is as fast as any such regexp can be. + ++++ +** New functions to handle the URL variant of base-64 encoding. +New functions 'base64url-encode-string' and 'base64url-encode-region' +implement the url-variant of base-64 encoding as defined in RFC4648. + +The functions 'base64-decode-string' and 'base64-decode-region' now +accept an optional argument to decode the URL variant of base-64 +encoding. + ++++ +** The function 'file-size-human-readable' accepts more optional arguments. +The new third argument is a string put between the number and unit; it +defaults to the empty string. The new fourth argument is a string +representing the unit to use; it defaults to "B" when the second +argument is 'iec' and the empty string otherwise. We recommend a +space or non-breaking space as third argument, and "B" as fourth +argument, circumstances allowing. + ++++ +** 'format-spec' has been expanded with several modifiers to allow +greater flexibility when customizing variables. The modifiers include +zero-padding, upper- and lower-casing, and limiting the length of the +interpolated strings. The function has now also been documented in +the Emacs Lisp manual. + ++++ +** 'directory-files-recursively' can now take an optional PREDICATE +parameter to control descending into subdirectories, and a +FOLLOW-SYMLINK parameter to say that symbolic links that point to +other directories should be followed. + ++++ +** New function 'xor' returns the boolean exclusive-or of its args. +The function was previously defined in array.el, but has been moved to +subr.el so that it is available by default. It now always returns the +non-nil argument when the other is nil. Several duplicates of 'xor' +in other packages are now obsolete aliases of 'xor'. + ++++ +** 'define-globalized-minor-mode' now takes BODY forms. + ++++ +** New text property 'help-echo-inhibit-substitution'. +Setting this on the first character of a help string disables +conversions via 'substitute-command-keys'. + ++++ +** New text property 'minibuffer-message'. +Setting this on a character of the minibuffer text will display the +temporary echo messages before that character, when messages need to +be displayed while minibuffer is active. + ++++ +** 'undo' can be made to ignore the active region for a command +by setting 'undo-inhibit-region' symbol property of that command to +non-nil. This is used by 'mouse-drag-region' to make the effect +easier to undo immediately afterwards. + +--- +** When called interactively, 'next-buffer' and 'previous-buffer' now +signal 'user-error' if there is no buffer to switch to. + + +* Changes in Emacs 27.1 on Non-Free Operating Systems + +--- +** Battery status is now supported in all Cygwin builds. +Previously it was supported only in the Cygwin-w32 build. + +** Emacs now handles key combinations involving the macOS "command" +and "option" modifier keys more correctly. + +** MacOS modifier key behavior is now more adjustable. +The behavior of the macOS "Option", "Command", "Control" and +"Function" keys can now be specified separately for use with +ordinary keys, function keys and mouse clicks. This allows using them +in their standard macOS way for composing characters. + +** The special handling of 'frame-title-format' on NS where setting it +to t would enable the macOS proxy icon has been replaced with a +separate variable, 'ns-use-proxy-icon'. 'frame-title-format' will now +work as on other platforms. + +--- +** New primitive 'w32-read-registry'. +This primitive lets Lisp programs access the MS-Windows Registry by +retrieving values stored under a given key. It is intended to be used +for supporting features such as XDG-like location of important files +and directories. + ++++ +** The default value of 'w32-pipe-read-delay' is now zero. +This speeds up reading output from sub-processes that produce a lot of +data. + +This variable may need to be non-zero only when running DOS programs +as Emacs subprocesses, which by now is not supported on modern +versions of MS-Windows. Set this variable to 50 if for some reason +you need the old behavior (and please report such situations to Emacs +developers). + +--- +** New variable 'w32-multibyte-code-page'. +This variable holds the value of the multibyte code page used by the +system. It is usually zero, which indicates that 'w32-ansi-code-page' +is being used, except in Far Eastern locales. When this variable is +non-zero, Emacs at startup sets 'locale-coding-system' to the +corresponding encoding, instead of using 'w32-ansi-code-page'. + +--- +** The default value of 'inhibit-compacting-font-caches' is t on MS-Windows. +Experience shows that compacting font caches causes more trouble on +MS-Windows than it helps. + ++++ +** Font lookup on MS-Windows was improved to support rare scripts. +To activate the improvement, run the new function +'w32-find-non-USB-fonts' once per Emacs session, or assign to the new +variable 'w32-non-USB-fonts' the list of scripts and the corresponding +fonts. See the documentation of this function and variable in the +Emacs manual for more details. + ++++ +** On NS the behavior of drag and drop can now be modified by use of +modifier keys in line with Apples guidelines. This makes the drag and +drop behavior more consistent, as previously the sending application +was able to 'set' modifiers without the knowledge of the user. + +** On NS multicolor font display is enabled again since it is also +implemented in Emacs on free operating systems via Cairo drawing. + + +---------------------------------------------------------------------- +This file is part of GNU Emacs. + +GNU Emacs is free software: you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation, either version 3 of the License, or +(at your option) any later version. + +GNU Emacs is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. + + +Local variables: +coding: utf-8 +mode: outline +paragraph-separate: "[ ]*$" +end: |