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diff --git a/etc/NEWS.26 b/etc/NEWS.26 new file mode 100644 index 00000000000..00ff9cda8ef --- /dev/null +++ b/etc/NEWS.26 @@ -0,0 +1,2106 @@ +GNU Emacs NEWS -- history of user-visible changes. + +Copyright (C) 2016-2018 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 26. + +See file HISTORY for a list of GNU Emacs versions and release dates. +See files NEWS.25, NEWS.24, ..., 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 necessary documentation updates have been done. + (This means all the relevant manuals in doc/ AND lisp doc-strings.) +--- means doc strings are updated, and no change in the manuals is needed. +When you add a new item, use the appropriate mark if you are sure it applies, + + +* Installation Changes in Emacs 26.1 + +--- +** By default libgnutls is now required when building Emacs. +Use 'configure --with-gnutls=no' to build even when GnuTLS is missing. + +--- +** GnuTLS version 2.12.2 or later is now required, instead of merely +version 2.6.6 or later. + ++++ +** The new option 'configure --with-mailutils' causes Emacs to rely on +GNU Mailutils to retrieve email. It is recommended, and is the +default if GNU Mailutils is installed. When --with-mailutils is not +in effect, the Emacs build procedure by default continues to build and +install a limited 'movemail' substitute that retrieves POP3 email only +via insecure channels. To avoid this problem, use either +--with-mailutils or --without-pop when configuring; --without-pop +is the default on platforms other than native MS-Windows. + +--- +** The new option 'configure --enable-gcc-warnings=warn-only' causes +GCC to issue warnings without stopping the build. This behavior is +now the default in developer builds. As before, use +'--disable-gcc-warnings' to suppress GCC's warnings, and +'--enable-gcc-warnings' to stop the build if GCC issues warnings. + +--- +** When GCC warnings are enabled, '--enable-check-lisp-object-type' is +now enabled by default when configuring. + ++++ +** The Emacs server now has socket-launching support. This allows +socket based activation, where an external process like systemd can +invoke the Emacs server process upon a socket connection event and +hand the socket over to Emacs. Emacs uses this socket to service +emacsclient commands. This new functionality can be disabled with the +configure option '--disable-libsystemd'. + ++++ +** A systemd user unit file is provided. Use it in the standard way: +'systemctl --user enable emacs'. +(If your Emacs is installed in a non-standard location, you may +need to copy the emacs.service file to eg ~/.config/systemd/user/) + +--- +** New configure option '--disable-build-details' attempts to build an +Emacs that is more likely to be reproducible; that is, if you build +and install Emacs twice, the second Emacs is a copy of the first. +Deterministic builds omit the build date from the output of the +'emacs-version' and 'erc-cmd-SV' functions, and the leave the +following variables nil: 'emacs-build-system', 'emacs-build-time', +'erc-emacs-build-time'. + +--- +** Emacs can now be built with support for Little CMS. + +If the lcms2 library is installed, Emacs will enable features built on +top of that library. The new configure option '--without-lcms2' can +be used to build without lcms2 support even if it is installed. Emacs +linked to Little CMS exposes color management functions in Lisp: the +color metrics 'lcms-cie-de2000' and 'lcms-cam02-ucs', as well as +functions for conversion to and from CIE CAM02 and CAM02-UCS. + +--- +** The configure option '--with-gameuser' now defaults to 'no', +as this appears to be the most common configuration in practice. +When it is 'no', the shared game directory and the auxiliary program +update-game-score are no longer needed and are not installed. + +--- +** Emacs no longer works on IRIX. We expect that Emacs users are not +affected by this, as SGI stopped supporting IRIX in December 2013. + + +* Startup Changes in Emacs 26.1 + ++++ +** New option '--fg-daemon'. This is the same as '--daemon', except +it runs in the foreground and does not fork. This is intended for +modern init systems such as systemd, which manage many of the traditional +aspects of daemon behavior themselves. '--bg-daemon' is now an alias +for '--daemon'. + ++++ +** New option '--module-assertions'. +When given this option, Emacs will perform expensive correctness +checks when dealing with dynamic modules. This is intended for module +authors that wish to verify that their module conforms to the module +requirements. The option makes Emacs abort if a module-related +assertion triggers. + ++++ +** Emacs now supports 24-bit colors on capable text terminals. +Terminal is automatically initialized to use 24-bit colors if the +required capabilities are found in terminfo. See the FAQ node +"(efaq) Colors on a TTY" for more information. + ++++ +** Emacs now obeys the X resource "scrollBar" at startup. +The effect is similar to that of "toolBar" resource on the tool bar. + + +* Changes in Emacs 26.1 + ++++ +** Option 'buffer-offer-save' can be set to new value, 'always'. When +set to 'always', the command 'save-some-buffers' will always offer +this buffer for saving. + +** Security vulnerability related to Enriched Text mode is removed. + ++++ +*** Enriched Text mode does not evaluate Lisp in 'display' properties. +This feature allows saving 'display' properties as part of text. +Emacs 'display' properties support evaluation of arbitrary Lisp forms +as part of processing the property for display, so displaying Enriched +Text could be vulnerable to executing arbitrary malicious Lisp code +included in the text (e.g., sent as part of an email message). +Therefore, execution of arbitrary Lisp forms in 'display' properties +decoded by Enriched Text mode is now disabled by default. Customize +the new option 'enriched-allow-eval-in-display-props' to a non-nil +value to allow Lisp evaluation in decoded 'display' properties. + +This vulnerability was introduced in Emacs 21.1. To work around that +in Emacs versions before 25.3, append the following to your ~/.emacs +init file: + + (eval-after-load "enriched" + '(defun enriched-decode-display-prop (start end &optional param) + (list start end))) + ++++ +** Functions in 'write-contents-functions' can fully short-circuit the +'save-buffer' process. Previously, saving a buffer that was not +visiting a file would always prompt for a file name. Now it only does +so if 'write-contents-functions' is nil (or all its functions return +nil). + +--- +** New variable 'executable-prefix-env' for inserting magic signatures. +This variable affects the format of the interpreter magic number +inserted by 'executable-set-magic'. If non-nil, the magic number now +takes the form "#!/usr/bin/env interpreter", otherwise the value +determined by 'executable-prefix', which is by default +"#!/path/to/interpreter". By default, 'executable-prefix-env' is nil, +so the default behavior is not changed. + ++++ +** The variable 'emacs-version' no longer includes the build number. +This is now stored separately in a new variable, 'emacs-build-number'. + ++++ +** Emacs now provides a limited form of concurrency with Lisp threads. +Concurrency in Emacs Lisp is "mostly cooperative", meaning that +Emacs will only switch execution between threads at well-defined +times: when Emacs waits for input, during blocking operations related +to threads (such as mutex locking), or when the current thread +explicitly yields. Global variables are shared among all threads, but +a 'let' binding is thread-local. Each thread also has its own current +buffer and its own match data. + +See the chapter "(elisp) Threads" in the ELisp manual for full +documentation of these facilities. + ++++ +** The new user variable 'electric-quote-chars' provides a list +of curved quotes for 'electric-quote-mode', allowing user to choose +the types of quotes to be used. + +--- +** The new user option 'electric-quote-context-sensitive' makes +'electric-quote-mode' context sensitive. If it is non-nil, you can +type an ASCII apostrophe to insert an opening or closing quote, +depending on context. Emacs will replace the apostrophe by an opening +quote character at the beginning of the buffer, the beginning of a +line, after a whitespace character, and after an opening parenthesis; +and it will replace the apostrophe by a closing quote character in all +other cases. + +--- +** The new variable 'electric-quote-inhibit-functions' controls when +to disable electric quoting based on context. Major modes can add +functions to this list; Emacs will temporarily disable +'electric-quote-mode' whenever any of the functions returns non-nil. +This can be used by major modes that derive from 'text-mode' but allow +inline code segments, such as 'markdown-mode'. + ++++ +** The new user variable 'dired-omit-case-fold' allows the user to +customize the case-sensitivity of dired-omit-mode. It defaults to +the same sensitivity as that of the filesystem for the corresponding +dired buffer. + ++++ +** Emacs now uses double buffering to reduce flicker when editing and +resizing graphical Emacs frames on the X Window System. This support +requires the DOUBLE-BUFFER extension, which major X servers have +supported for many years. If your system has this extension, but an +Emacs built with double buffering misbehaves on some displays you use, +you can disable the feature by adding + + '(inhibit-double-buffering . t) + +to default-frame-alist. Or inject this parameter into the selected +frame by evaluating this form: + + (modify-frame-parameters nil '((inhibit-double-buffering . t))) + +--- +** The customization group 'wp', whose label was "text", is now +deprecated. Use the new group 'text', which inherits from 'wp', +instead. + ++++ +** The new function 'call-shell-region' executes a command in an +inferior shell with the buffer region as input. + ++++ +** The new user option 'shell-command-dont-erase-buffer' controls +if the output buffer is erased between shell commands; if non-nil, +the output buffer is not erased; this variable also controls where +to set the point in the output buffer: beginning of the output, +end of the buffer or save the point. +When 'shell-command-dont-erase-buffer' is nil, the default value, +the behavior of 'shell-command', 'shell-command-on-region' and +'async-shell-command' is as usual. + ++++ +** The new user option 'async-shell-command-display-buffer' controls +whether the output buffer of an asynchronous command is shown +immediately, or only when there is output. + ++++ +** New user option 'mouse-select-region-move-to-beginning'. +This option controls the position of point when double-clicking +mouse-1 on the end of a parenthetical grouping or string-delimiter: +the default value nil keeps point at the end of the region, setting it +to non-nil moves point to the beginning of the region. + ++++ +** New user option 'mouse-drag-and-drop-region'. +This option allows you to drag the entire region of text to another +place or another buffer. Its behavior is customizable via the new +options 'mouse-drag-and-drop-region-cut-when-buffers-differ', +'mouse-drag-and-drop-region-show-tooltip', and +'mouse-drag-and-drop-region-show-cursor'. + ++++ +** The new user option 'confirm-kill-processes' allows the user to +skip a confirmation prompt for killing subprocesses when exiting +Emacs. When set to t (the default), Emacs will prompt for +confirmation before killing subprocesses on exit, which is the same +behavior as before. + +--- +** 'find-library-name' will now fall back on looking at 'load-history' +to try to locate libraries that have been loaded with an explicit path +outside 'load-path'. + ++++ +** Faces in 'minibuffer-prompt-properties' no longer overwrite properties +in the text in functions like 'read-from-minibuffer', but instead are +added to the end of the face list. This allows users to say things +like '(read-from-minibuffer (propertize "Enter something: " 'face 'bold))'. + ++++ +** The new variable 'extended-command-suggest-shorter' has been added +to control whether to suggest shorter 'M-x' commands or not. + +--- +** icomplete now respects 'completion-ignored-extensions'. + ++++ +** Non-breaking hyphens are now displayed with the 'nobreak-hyphen' +face instead of the 'escape-glyph' face. + ++++ +** Approximations to quotes are now displayed with the new 'homoglyph' +face instead of the 'escape-glyph' face. + ++++ +** New face 'header-line-highlight'. +This face is the header-line analogue of 'mode-line-highlight'; it +should be the preferred mouse-face for mouse-sensitive elements in the +header line. + +--- +** 'C-x h' ('mark-whole-buffer') will now avoid marking the prompt +part of minibuffers. + +--- +** 'fill-paragraph' no longer marks the buffer as changed unless it +actually changed something. + +--- +** The locale language name 'ca' is now mapped to the language +environment 'Catalan', which has been added. + +--- +** 'align-regexp' has a separate history for its interactive argument. +'align-regexp' no longer shares its history with all other +history-less functions that use 'read-string'. + ++++ +** The networking code has been reworked so that it's more +asynchronous than it was (when specifying :nowait t in +'make-network-process'). How asynchronous it is varies based on the +capabilities of the system, but on a typical GNU/Linux system the DNS +resolution, the connection, and (for TLS streams) the TLS negotiation +are all done without blocking the main Emacs thread. To get +asynchronous TLS, the TLS boot parameters have to be passed in (see +the manual for details). + +Certain process oriented functions (like 'process-datagram-address') +will block until socket setup has been performed. The recommended way +to deal with asynchronous sockets is to avoid interacting with them +until they have changed status to "run". This is most easily done +from a process sentinel. + +--- +** 'make-network-process' and 'open-network-stream' sometimes allowed +:service to be an integer string (e.g., :service "993") and sometimes +required an integer (e.g., :service 993). This difference has been +eliminated, and integer strings work everywhere. + +--- +** It is possible to disable attempted recovery on fatal signals. +Two new variables support disabling attempts to recover from stack +overflow and to avoid automatic auto-save when Emacs is delivered a +fatal signal. 'attempt-stack-overflow-recovery', if set to nil, +will disable attempts to recover from C stack overflows; Emacs will +then crash as with any other fatal signal. +'attempt-orderly-shutdown-on-fatal-signal', if set to nil, will +disable attempts to auto-save the session and shut down in an orderly +fashion when Emacs receives a fatal signal; instead, Emacs will +terminate immediately. Both variables are non-nil by default. +These variables are for users who would like to avoid the small +probability of data corruption due to techniques Emacs uses to recover +in these situations. + ++++ +** File local and directory local variables are now initialized each +time the major mode is set, not just when the file is first visited. +These local variables will thus not vanish on setting a major mode. + ++++ +** A second dir-local file (.dir-locals-2.el) is now accepted. +See the doc string of 'dir-locals-file' for more information. + ++++ +** Connection-local variables can be used to specify local variables +with a value depending on the connected remote server. For details, +see the node "(elisp) Connection Local Variables" in the ELisp manual. + +--- +** International domain names (IDNA) are now encoded via the new +puny.el library, so that one can visit Web sites with non-ASCII URLs. + ++++ +** The new 'list-timers' command lists all active timers in a buffer, +where you can cancel them with the 'c' command. + ++++ +** 'switch-to-buffer-preserve-window-point' now defaults to t. +Applications that call 'switch-to-buffer' and want to show the buffer at +the position of its point should use 'pop-to-buffer-same-window' in lieu +of 'switch-to-buffer'. + ++++ +** The new variable 'debugger-stack-frame-as-list' allows displaying +all call stack frames in a Lisp backtrace buffer as lists. Both +debug.el and edebug.el have been updated to heed to this variable. + +--- +** Values in call stack frames are now displayed using 'cl-prin1'. +The old behavior of using 'prin1' can be restored by customizing the +new option 'debugger-print-function'. + ++++ +** NUL bytes in text copied to the system clipboard are now replaced with "\0". + ++++ +** The new variable 'x-ctrl-keysym' has been added to the existing +roster of X keysyms. It can be used in combination with another +variable of this kind to swap modifiers in Emacs. + +--- +** New input methods: 'cyrillic-tuvan', 'polish-prefix', 'uzbek-cyrillic'. + +--- +** The 'dutch' input method no longer attempts to support Turkish too. +Also, it no longer converts 'IJ' and 'ij' to the compatibility +characters U+0132 LATIN CAPITAL LIGATURE IJ and U+0133 LATIN SMALL +LIGATURE IJ. + ++++ +** File name quoting by adding the prefix "/:" is now possible for the +local part of a remote file name. Thus, if you have a directory named +"/~" on the remote host "foo", you can prevent it from being +substituted by a home directory by writing it as "/foo:/:/~/file". + ++++ +** The new variable 'maximum-scroll-margin' allows having effective +settings of 'scroll-margin' up to half the window size, instead of +always restricting the margin to a quarter of the window. + ++++ +** Emacs can scroll horizontally using mouse, touchpad, and trackbar. +You can enable this by customizing 'mwheel-tilt-scroll-p'. If you +want to reverse the direction of the scroll, customize +'mwheel-flip-direction'. + ++++ +** The default GnuTLS priority string now includes %DUMBFW. +This is to avoid bad behavior in some firewalls, which causes the +connection to be closed by the remote host. + +** Emacsclient changes + ++++ +*** Emacsclient has a new option '-u' / '--suppress-output'. +This option suppresses display of return values from the server +process. + ++++ +*** Emacsclient has a new option '-T' / '--tramp'. +This helps with using a local Emacs session as the server for a remote +emacsclient. With appropriate setup, one can now set the EDITOR +environment variable on a remote machine to emacsclient, and +use the local Emacs to edit remote files via Tramp. See the node +"(emacs) emacsclient Options" in the user manual for the details. + ++++ +*** Emacsclient now accepts command-line options in ALTERNATE_EDITOR +and '--alternate-editor'. For example, ALTERNATE_EDITOR="emacs -Q -nw". +Arguments may be quoted "like this", so that for example an absolute +path containing a space may be specified; quote escaping is not +supported. + +--- +** New user option 'dig-program-options' and extended functionality +for DNS-querying functions 'nslookup-host', 'dns-lookup-host', +and 'run-dig'. Each function now accepts an optional name server +argument interactively (with a prefix argument) and non-interactively. + ++++ +** 'describe-key-briefly' now ignores mouse movement events. + ++++ +** The new variable 'eval-expression-print-maximum-character' prevents +large integers from being displayed as characters by 'M-:' and similar +commands. + +--- +** Two new commands for finding the source code of Emacs Lisp +libraries: 'find-library-other-window' and 'find-library-other-frame'. + ++++ +** The new variable 'display-raw-bytes-as-hex' allows you to change +the display of raw bytes from octal to hex. + ++++ +** You can now provide explicit field numbers in format specifiers. +For example, '(format "%2$s %1$s %2$s" "X" "Y")' produces "Y X Y". + ++++ +** Emacs now supports optional display of line numbers in the buffer. +This is similar to what 'linum-mode' provides, but much faster and +doesn't usurp the display margin for the line numbers. Customize the +buffer-local variable 'display-line-numbers' to activate this optional +display. Alternatively, you can use the 'display-line-numbers-mode' +minor mode or the global 'global-display-line-numbers-mode'. When +using these modes, customize 'display-line-numbers-type' with the same +value as you would use with 'display-line-numbers'. + +Line numbers are not displayed at all in minibuffer windows and in +tooltips, as they are not useful there. + +Lisp programs can disable line-number display for a particular screen +line by putting the 'display-line-numbers-disable' text property or +overlay property on the first character of that screen line. This is +intended for add-on packages that need a finer control of the display. + +Lisp programs that need to know how much screen estate is used up for +line-number display in a window can use the new function +'line-number-display-width'. + +'linum-mode' and all similar packages are henceforth becoming obsolete. +Users and developers are encouraged to switch to this new feature +instead. + +--- +** The new user option 'arabic-shaper-ZWNJ-handling' controls how to +handle ZWNJ in Arabic text rendering. + + +* Editing Changes in Emacs 26.1 + ++++ +** New variable 'column-number-indicator-zero-based'. +Traditionally, in Column Number mode, the displayed column number +counts from zero starting at the left margin of the window. This +behavior is now controlled by 'column-number-indicator-zero-based'. +If you would prefer for the displayed column number to count from one, +you may set this variable to nil. (Behind the scenes, there is now a +new mode line construct, '%C', which operates exactly as '%c' does +except that it counts from one.) + ++++ +** New single-line horizontal scrolling mode. +The 'auto-hscroll-mode' variable can now have a new special value, +'current-line', which causes only the line where the cursor is +displayed to be horizontally scrolled when lines are truncated on +display and point moves outside the left or right window margin. + ++++ +** New mode line constructs '%o' and '%q', and user option +'mode-line-percent-position'. '%o' displays the "degree of travel" of +the window through the buffer. Unlike the default '%p', this +percentage approaches 100% as the window approaches the end of the +buffer. '%q' displays the percentage offsets of both the start and +the end of the window, e.g. "5-17%". The new option +'mode-line-percent-position' makes it easier to switch between '%p', +'%P', and these new constructs. + ++++ +** Two new user options 'list-matching-lines-jump-to-current-line' and +'list-matching-lines-current-line-face' to show the current line +highlighted in *Occur* buffer. + ++++ +** The 'occur' command can now operate on the region. + ++++ +** New bindings for 'query-replace-map'. +'undo', undo the last replacement; bound to 'u'. +'undo-all', undo all replacements; bound to 'U'. + +--- +** 'delete-trailing-whitespace' deletes whitespace after form feed. +In modes where form feed was treated as a whitespace character, +'delete-trailing-whitespace' would keep lines containing it unchanged. +It now deletes whitespace after the last form feed thus behaving the +same as in modes where the character is not whitespace. + +--- +** Emacs no longer prompts about editing a changed file when the file's +content is unchanged. Instead of only checking the modification time, +Emacs now also checks the file's actual content before prompting the user. + +--- +** Various casing improvements. + +*** 'upcase', 'upcase-region' et al. convert title case characters +(such as Dz) into their upper case form (such as DZ). + +*** 'capitalize', 'upcase-initials' et al. make use of title-case forms +of initial characters (correctly producing for example Džungla instead +of incorrect DŽungla). + +*** Characters which turn into multiple ones when cased are correctly handled. +For example, fi ligature is converted to FI when upper cased. + +*** Greek small sigma is correctly handled when at the end of the word. +Strings such as ΌΣΟΣ are now correctly converted to Όσος when +capitalized instead of incorrect Όσοσ (compare lowercase sigma at the +end of the word). + ++++ +** Emacs can now auto-save buffers to visited files in a more robust +manner via the new mode 'auto-save-visited-mode'. Unlike +'auto-save-visited-file-name', this mode uses the normal saving +procedure and therefore obeys saving hooks. +'auto-save-visited-file-name' is now obsolete. + ++++ +** New behavior of 'mark-defun'. +Prefix argument selects that many (or that many more) defuns. +Negative prefix arg flips the direction of selection. Also, +'mark-defun' between defuns correctly selects N following defuns (or +-N previous for negative arguments). Finally, comments preceding the +defun are selected unless they are separated from the defun by a blank +line. + +--- +** New command 'replace-buffer-contents'. +This command replaces the contents of the accessible portion of the +current buffer with the contents of the accessible portion of a +different buffer while keeping point, mark, markers, and text +properties as intact as possible. + ++++ +** New commands 'apropos-local-variable' and 'apropos-local-value'. +These are buffer-local versions of 'apropos-variable' and +'apropos-value', respectively. They show buffer-local variables whose +names and values, respectively, match a given pattern. + ++++ +** More user control of reordering bidirectional text for display. +The two new variables, 'bidi-paragraph-start-re' and +'bidi-paragraph-separate-re', allow customization of what exactly are +paragraphs, for the purposes of bidirectional display. + +--- +** 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). + + +* Changes in Specialized Modes and Packages in Emacs 26.1 + +--- +** Emacs 26.1 comes with Org v9.1.6. +See the file ORG-NEWS for user-visible changes in Org. + +--- +** New function 'cl-generic-p'. + +** Dired + ++++ +*** You can answer 'all' in 'dired-do-delete' to delete recursively all +remaining directories without more prompts. + ++++ +*** Dired supports wildcards in the directory part of the file names. + ++++ +*** You can now use '`?`' in 'dired-do-shell-command'. +It gets replaced by the current file name, like ' ? '. + ++++ +*** A new option 'dired-always-read-filesystem' defaulting to nil. +If non-nil, buffers visiting files are reverted before they are +searched; for instance, in 'dired-mark-files-containing-regexp' a +non-nil value of this option means the file is revisited in a +temporary buffer; this temporary buffer is the actual buffer searched: +the original buffer visiting the file is not modified. + +--- +*** Users can now customize mouse clicks in Dired in a more flexible way. +The new command 'dired-mouse-find-file' can be bound to a mouse click +and used to visit files/directories in Dired in the selected window. +The new command 'dired-mouse-find-file-other-frame' similarly visits +files/directories in another frame. You can write your own commands +that invoke 'dired-mouse-find-file' with non-default optional +arguments, to tailor the effects of mouse clicks on file names in +Dired buffers. + ++++ +*** In wdired, when editing files to contain slash characters, +the resulting directories are automatically created. Whether to do +this is controlled by the 'wdired-create-parent-directories' variable. + ++++ +*** 'W' is now bound to 'browse-url-of-dired-file', and is useful for +viewing HTML files and the like. + +--- +*** New variable 'dired-clean-confirm-killing-deleted-buffers' +controls whether Dired asks to kill buffers visiting deleted files and +directories. The default is t, so Dired asks for confirmation, to +keep previous behavior. + +--- +** html2text is now marked obsolete. + +--- +** smerge-refine-regions can refine regions in separate buffers. + +--- +** Info menu and index completion uses substring completion by default. +This can be customized via the 'info-menu' category in +'completion-category-overrides'. + ++++ +** The ancestor buffer is shown by default in 3-way merges. +A new option 'ediff-show-ancestor' and a new toggle +'ediff-toggle-show-ancestor'. + +--- +** TeX: Add luatex and xetex as alternatives to pdftex + +** Electric-Buffer-menu + ++++ +*** Key 'U' is bound to 'Buffer-menu-unmark-all' and key 'M-DEL' is +bound to 'Buffer-menu-unmark-all-buffers'. + ++++ +** hideshow mode got four key bindings that are analogous to outline +mode bindings: 'C-c @ C-a', 'C-c @ C-t', 'C-c @ C-d', and 'C-c @ C-e'. + +** bs + +--- +*** Two new commands 'bs-unmark-all', bound to 'U', and +'bs-unmark-previous', bound to <backspace>. + +** Buffer-menu + ++++ +*** Two new commands 'Buffer-menu-unmark-all', bound to 'U' and +'Buffer-menu-unmark-all-buffers', bound to 'M-DEL'. + +--- +** Checkdoc + +*** 'checkdoc-arguments-in-order-flag' now defaults to nil. + +** Gnus + +--- +*** The ~/.newsrc file will now only be saved if the native select +method is an NNTP select method. + ++++ +*** A new command for sorting articles by readedness marks has been +added: 'C-c C-s C-m C-m'. + ++++ +*** In 'message-citation-line-format' the '%Z' format is now the time +zone name instead of the numeric form. The '%z' format continues to +be the numeric form. The new behavior is compatible with +'format-time-string'. + +** Ibuffer + +--- +*** New command 'ibuffer-jump'. + +--- +*** New filter commands 'ibuffer-filter-by-basename', +'ibuffer-filter-by-file-extension', 'ibuffer-filter-by-directory', +'ibuffer-filter-by-starred-name', 'ibuffer-filter-by-modified' +and 'ibuffer-filter-by-visiting-file'; bound respectively +to '/b', '/.', '//', '/*', '/i' and '/v'. + +--- +*** Two new commands 'ibuffer-filter-chosen-by-completion' +and 'ibuffer-and-filter', the second bound to '/&'. + +--- +*** The commands 'ibuffer-pop-filter', 'ibuffer-pop-filter-group', +'ibuffer-or-filter' and 'ibuffer-filter-disable' have the alternative +bindings '/<up>', '/S-<up>', '/|' and '/DEL', respectively. + +--- +*** The data format specifying filters has been extended to allow +explicit logical 'and', and a more flexible form for logical 'not'. +See 'ibuffer-filtering-qualifiers' doc string for full details. + +--- +*** A new command 'ibuffer-copy-buffername-as-kill'; bound +to 'B'. + +--- +*** New command 'ibuffer-change-marks'; bound to '* c'. + +--- +*** A new command 'ibuffer-mark-by-locked' to mark +all locked buffers; bound to '% L'. + +--- +*** A new option 'ibuffer-locked-char' to indicate +locked buffers; Ibuffer shows a new column displaying +'ibuffer-locked-char' for locked buffers. + +--- +*** A new command 'ibuffer-unmark-all-marks' to unmark +all buffers without asking confirmation; bound to +'U'; 'ibuffer-do-replace-regexp' bound to 'r'. + +--- +*** A new command 'ibuffer-mark-by-content-regexp' to mark buffers +whose content matches a regexp; bound to '% g'. + +--- +*** Two new options 'ibuffer-never-search-content-name' and +'ibuffer-never-search-content-mode' used by +'ibuffer-mark-by-content-regexp'. + +** Browse-URL + +--- +*** Support for opening links to man pages in Man or WoMan mode. + +** Comint + +--- +*** New user option 'comint-move-point-for-matching-input' to control +where to place point after 'C-c M-r' and 'C-c M-s'. + ++++ +*** New user option 'comint-terminfo-terminal'. +This option allows control of the value of the TERM environment +variable Emacs puts into the environment of the Comint mode and its +derivatives, such as Shell mode and Compilation Shell minor-mode. The +default is "dumb", for compatibility with previous behavior. + +** Compilation mode + +--- +*** Messages from CMake are now recognized. + ++++ +*** The number of errors, warnings, and informational messages is now +displayed in the mode line. These are updated as compilation +proceeds. + +** Grep + +--- +*** Grep commands will now use GNU grep's '--null' option if +available, which allows distinguishing the filename from contents if +they contain colons. This can be controlled by the new custom option +'grep-use-null-filename-separator'. + +--- +*** The grep/rgrep/lgrep functions will now ask about saving files +before running. This is controlled by the 'grep-save-buffers' +variable. + +** Edebug + +--- +*** Edebug can be prevented from pausing 1 second after reaching a +breakpoint (e.g. with "f" and "o") by customizing the new option +'edebug-sit-on-break'. + ++++ +*** New customizable option 'edebug-max-depth'. +This allows you to enlarge the maximum recursion depth when +instrumenting code. + +** Eshell + +--- +*** 'eshell-input-filter's value is now a named function +'eshell-input-filter-default', and has a new custom option +'eshell-input-filter-initial-space' to ignore adding commands prefixed +with blank space to eshell history. + +** EUDC + +--- +*** Backward compatibility support for BBDB versions less than 3 +(i.e., BBDB 2.x) is deprecated and will likely be removed in the next +major release of Emacs. Users of BBDB 2.x should plan to upgrade to +BBDB 3.x. + +** eww + ++++ +*** New 'M-RET' command for opening a link at point in a new eww buffer. + ++++ +*** A new 's' command for switching to another eww buffer via the minibuffer. + +--- +*** The 'o' command ('shr-save-contents') has moved to 'O' to avoid collision +with the 'o' command from 'image-map'. + ++++ +*** A new command 'C' ('eww-toggle-colors') can be used to toggle +whether to use the HTML-specified colors or not. The user can also +customize the 'shr-use-colors' variable. + +--- +*** Images that are being loaded are now marked with gray +"placeholder" images of the size specified by the HTML. They are then +replaced by the real images asynchronously, which will also now +respect width/height HTML specs (unless they specify widths/heights +bigger than the current window). + +--- +*** The 'w' command on links is now 'shr-maybe-probe-and-copy-url'. +'shr-copy-url' now only copies the url at point; users who wish to +avoid accidentally accessing remote links may rebind 'w' and 'u' in +'eww-link-keymap' to it. + +** Ido + +--- +*** The commands 'find-alternate-file-other-window', +'dired-other-window', 'dired-other-frame', and +'display-buffer-other-window' are now remapped to Ido equivalents if +Ido mode is active. + +** Images + ++++ +*** Images are automatically scaled before displaying based on the +'image-scaling-factor' variable (if Emacs supports scaling the images +in question). + ++++ +*** It's now possible to specify aspect-ratio preserving combinations +of :width/:max-height and :height/:max-width keywords. In either +case, the "max" keywords win. (Previously some combinations would, +depending on the aspect ratio of the image, just be ignored and in +other instances this would lead to the aspect ratio not being +preserved.) + ++++ +*** Images inserted with 'insert-image' and related functions get a +keymap put into the text properties (or overlays) that span the +image. This keymap binds keystrokes for manipulating size and +rotation, as well as saving the image to a file. These commands are +also available in 'image-mode'. + ++++ +*** A new library for creating and manipulating SVG images has been +added. See the "(elisp) SVG Images" section in the ELisp reference +manual for details. + ++++ +*** New setf-able function to access and set image parameters is +provided: 'image-property'. + +--- +*** New commands 'image-scroll-left' and 'image-scroll-right' +for 'image-mode' that complement 'image-scroll-up' and +'image-scroll-down': they have the same prefix arg behavior and stop +at image boundaries. + +** Image-Dired + +--- +*** Now provides a minor mode 'image-dired-minor-mode' which replaces +the function 'image-dired-setup-dired-keybindings'. + +--- +*** Thumbnail generation is now asynchronous. +The number of concurrent processes is limited by the variable +'image-dired-queue-active-limit'. + +--- +*** 'image-dired-thumbnail-storage' has a new option 'standard-large' +for generating 256x256 thumbnails according to the Thumbnail Managing +Standard. + +--- +*** Inherits movement keys from 'image-mode' for viewing full images. +This includes the usual char, line, and page movement commands. + +--- +*** All the -options types have been changed to argument lists +instead of shell command strings. This change affects +'image-dired-cmd-create-thumbnail-options', +'image-dired-cmd-create-temp-image-options', +'image-dired-cmd-rotate-thumbnail-options', +'image-dired-cmd-rotate-original-options', +'image-dired-cmd-write-exif-data-options', +'image-dired-cmd-read-exif-data-options', and introduces +'image-dired-cmd-pngnq-options', 'image-dired-cmd-pngcrush-options', +'image-dired-cmd-create-standard-thumbnail-options'. + +--- +*** Recognizes more tools by default, including pngnq-s9 and OptiPNG. + +--- +*** 'find-file' and related commands now work on thumbnails and +displayed images, providing a default argument of the original file name +via an addition to 'file-name-at-point-functions'. + +--- +** The default 'Info-default-directory-list' no longer checks some obsolete +directory suffixes (gnu, gnu/lib, gnu/lib/emacs, emacs, lib, lib/emacs) +when searching for info directories. + ++++ +** The commands that add ChangeLog entries now prefer a VCS root directory +for the ChangeLog file, if none already exists. Customize +'change-log-directory-files' to nil for the old behavior. + +--- +** Support for non-string values of 'time-stamp-format' has been removed. + +** Message + +--- +*** 'message-use-idna' now defaults to t (because Emacs comes with +built-in IDNA support now). + +--- +*** When sending HTML messages with embedded images, and you have +exiftool installed, and you rotate images with EXIF data (i.e., +JPEGs), the rotational information will be inserted into the outgoing +image in the message. (The original image will not have its +orientation affected.) + +--- +*** The 'message-valid-fqdn-regexp' variable has been removed, since +there are now top-level domains added all the time. Message will no +longer warn about sending emails to top-level domains it hasn't heard +about. + +--- +*** 'message-beginning-of-line' (bound to 'C-a') understands folded headers. +In 'visual-line-mode' it will look for the true beginning of a header +while in non-'visual-line-mode' it will move the point to the indented +header's value. + +** Package + ++++ +*** The new variable 'package-gnupghome-dir' has been added to control +where the GnuPG home directory (used for signature verification) is +located and whether GnuPG's option '--homedir' is used or not. + +--- +*** Deleting a package no longer respects 'delete-by-moving-to-trash'. + +** Python + ++++ +*** The new variable 'python-indent-def-block-scale' has been added. +It controls the depth of indentation of arguments inside multi-line +function signatures. + +** Tramp + ++++ +*** The method part of remote file names is mandatory now. +A valid remote file name starts with "/method:host:" or +"/method:user@host:". + ++++ +*** The new pseudo method "-" is a marker for the default method. +"/-::" is the shortest remote file name then. + ++++ +*** The command 'tramp-change-syntax' allows you to choose an +alternative remote file name syntax. + ++++ +*** New connection method "sg", which supports editing files under a +different group ID. + ++++ +*** New connection method "doas" for OpenBSD hosts. + ++++ +*** New connection method "gdrive", which allows access to Google +Drive onsite repositories. + ++++ +*** Gateway methods in Tramp have been removed. +Instead, the Tramp manual documents how to configure ssh and PuTTY +accordingly. + ++++ +*** Setting the "ENV" environment variable in +'tramp-remote-process-environment' enables reading of shell +initialization files. + +--- +*** Tramp is able now to send SIGINT to remote asynchronous processes. + +--- +*** Variable 'tramp-completion-mode' is obsoleted. + +--- +** 'auto-revert-use-notify' is set back to t in 'global-auto-revert-mode'. + +** JS mode + +--- +*** JS mode now sets 'comment-multi-line' to t. + +--- +*** New variable 'js-indent-align-list-continuation', when set to nil, +will not align continuations of bracketed lists, but will indent them +by the fixed width 'js-indent-level'. + +** CSS mode + +--- +*** Support for completing attribute values, at-rules, bang-rules, +HTML tags, classes and IDs using the 'completion-at-point' command. +Completion candidates for HTML classes and IDs are retrieved from open +HTML mode buffers. + +--- +*** CSS mode now binds 'C-h S' to a function that will show +information about a CSS construct (an at-rule, property, pseudo-class, +pseudo-element, with the default being guessed from context). By +default the information is looked up on the Mozilla Developer Network, +but this can be customized using 'css-lookup-url-format'. + +--- +*** CSS colors are fontified using the color they represent as the +background. For instance, #ff0000 would be fontified with a red +background. + ++++ +** Emacs now supports character name escape sequences in character and +string literals. The syntax variants '\N{character name}' and +'\N{U+code}' are supported. + ++++ +** Prog mode has some support for multi-mode indentation. +This allows better indentation support in modes that support multiple +programming languages in the same buffer, like literate programming +environments or ANTLR programs with embedded Python code. + +A major mode can provide indentation context for a sub-mode. To +support this, modes should use 'prog-first-column' instead of a +literal zero and avoid calling 'widen' in their indentation functions. +See the node "(elisp) Mode-Specific Indent" in the ELisp manual for +more details. + +** ERC + +--- +*** New variable 'erc-default-port-tls' used to connect to TLS IRC +servers. + +** URL + ++++ +*** The new function 'url-cookie-delete-cookie' can be used to +programmatically delete all cookies, or cookies from a specific +domain. + ++++ +*** 'url-retrieve-synchronously' now takes an optional timeout parameter. + +--- +*** The URL package now supports HTTPS over proxies supporting CONNECT. + ++++ +*** 'url-user-agent' now defaults to 'default', and the User-Agent +string is computed dynamically based on 'url-privacy-level'. + +** VC and related modes + ++++ +*** 'vc-dir-mode' now binds 'vc-log-outgoing' to 'O'; and has various +branch-related commands on a keymap bound to 'B'. + ++++ +*** 'vc-region-history' is now bound to 'C-x v h', replacing the older +'vc-insert-headers' binding. + +*** New user option 'vc-git-print-log-follow' to follow renames in Git logs +for a single file. + +** CC mode + +--- +*** Opening a .h file will turn C or C++ mode depending on language used. +This is done with the help of the 'c-or-c++-mode' function, which +analyzes buffer contents to infer whether it's a C or C++ source file. + +--- +** New option 'cpp-message-min-time-interval' to allow user control +of progress messages in cpp.el. + +--- +** New DNS mode command 'dns-mode-ipv6-to-nibbles' to convert IPv6 addresses +to a format suitable for reverse lookup zone files. + +** Ispell + ++++ +*** Enchant is now supported as a spell-checker. + +Enchant is a meta-spell-checker that uses providers such as Hunspell +to do the actual checking. With it, users can use spell-checkers not +directly supported by Emacs, such as Voikko, Hspell and AppleSpell, +more easily share personal word-lists with other programs, and +configure different spelling-checkers for different languages. +(Version 2.1.0 or later of Enchant is required.) + +** Flymake + ++++ +*** Flymake has been completely redesigned + +Flymake now annotates arbitrary buffer regions, not just lines. It +supports arbitrary diagnostic types, not just errors and warnings (see +variable 'flymake-diagnostic-types-alist'). + +It also supports multiple simultaneous backends, meaning that you can +check your buffer from different perspectives (see variable +'flymake-diagnostic-functions'). Backends for Emacs Lisp mode are +provided. + +The old Flymake behavior is preserved in the so-called "legacy +backend", which has been updated to benefit from the new UI features. + +** Term + +--- +*** `term-char-mode' now makes its buffer read-only. + +The buffer is made read-only to prevent changes from being made by +anything other than the process filter; and movements of point away +from the process mark are counter-acted so that the cursor is in the +correct position after each command. This is needed to avoid states +which are inconsistent with the state of the terminal understood by +the inferior process. + +New user options `term-char-mode-buffer-read-only' and +`term-char-mode-point-at-process-mark' control these behaviors, and +are non-nil by default. Customize these options to nil if you want +the previous behavior. + +** Xref + ++++ +*** When an *xref* buffer is needed, 'TAB' quits and jumps to an xref. + +A new command 'xref-quit-and-goto-xref', bound to 'TAB' in *xref* +buffers, quits the window before jumping to the destination. In many +situations, the intended window configuration is restored, just as if +the *xref* buffer hadn't been necessary in the first place. + + +* New Modes and Packages in Emacs 26.1 + +--- +** New Elisp data-structure library 'radix-tree'. + +--- +** New library 'xdg' with utilities for some XDG standards and specs. + +** HTML + ++++ +*** A new submode of 'html-mode', 'mhtml-mode', is now the default +mode for *.html files. This mode handles indentation, +fontification, and commenting for embedded JavaScript and CSS. + +--- +** New mode 'conf-toml-mode' is a sub-mode of 'conf-mode', specialized +for editing TOML files. + +--- +** New mode 'conf-desktop-mode' is a sub-mode of 'conf-unix-mode', +specialized for editing freedesktop.org desktop entries. + +--- +** New minor mode 'pixel-scroll-mode' provides smooth pixel-level scrolling. + +--- +** New major mode 'less-css-mode' (a minor variant of 'css-mode') for +editing Less files. + + +* Incompatible Lisp Changes in Emacs 26.1 + +--- +** 'password-data' is now a hash-table so that 'password-read' can use +any object for the 'key' argument. + ++++ +** Command 'dired-mark-extension' now automatically prepends a '.' to the +extension when not present. The new command 'dired-mark-suffix' behaves +similarly but it doesn't prepend a '.'. + ++++ +** Certain cond/pcase/cl-case forms are now compiled using a faster jump +table implementation. This uses a new bytecode op 'switch', which +isn't compatible with previous Emacs versions. This functionality can +be disabled by setting 'byte-compile-cond-use-jump-table' to nil. + ++++ +** If 'comment-auto-fill-only-comments' is non-nil, 'auto-fill-function' +is now called only if either no comment syntax is defined for the +current buffer or the self-insertion takes place within a comment. + +--- +** The alist 'ucs-names' is now a hash table. + +--- +** 'if-let' and 'when-let' are subsumed by 'if-let*' and 'when-let*'. +The incumbent 'if-let' and 'when-let' are now marked obsolete. +'if-let*' and 'when-let*' do not accept the single tuple special case. +New macro 'and-let*' is an implementation of the Scheme SRFI-2 syntax +of the same name. 'if-let*' and 'when-let*' now accept the same +binding syntax as 'and-let*'. + +--- +** 'C-up', 'C-down', 'C-left' and 'C-right' are now defined in term +mode to send the same escape sequences that xterm does. This makes +things like 'forward-word' in readline work. + +--- +** Customizable variable 'query-replace-from-to-separator' +now doesn't propertize the string value of the separator. +Instead, text properties are added by 'query-replace-read-from'. +Additionally, the new nil value restores pre-24.5 behavior +of not providing replacement pairs via the history. + +--- +** Some obsolete functions, variables, and faces have been removed: + +*** 'make-variable-frame-local'. Variables cannot be frame-local any more. + +*** From subr.el: 'window-dot', 'set-window-dot', 'read-input', +'show-buffer', 'eval-current-buffer', 'string-to-int'. + +*** 'icomplete-prospects-length'. + +*** All the default-FOO variables that hold the default value of the +FOO variable. Use 'default-value' and 'setq-default' to access and +change FOO, respectively. The exhaustive list of removed variables is: +'default-mode-line-format', 'default-header-line-format', +'default-line-spacing', 'default-abbrev-mode', 'default-ctl-arrow', +'default-truncate-lines', 'default-left-margin', 'default-tab-width', +'default-case-fold-search', 'default-left-margin-width', +'default-right-margin-width', 'default-left-fringe-width', +'default-right-fringe-width', 'default-fringes-outside-margins', +'default-scroll-bar-width', 'default-vertical-scroll-bar', +'default-indicate-empty-lines', 'default-indicate-buffer-boundaries', +'default-fringe-indicator-alist', 'default-fringe-cursor-alist', +'default-scroll-up-aggressively', 'default-scroll-down-aggressively', +'default-fill-column', 'default-cursor-type', +'default-cursor-in-non-selected-windows', +'default-buffer-file-coding-system', 'default-major-mode', and +'default-enable-multibyte-characters'. + +*** Many variables obsoleted in 22.1 referring to face symbols. + ++++ +** The variable 'text-quoting-style' is now a customizable option. It +controls whether to and how to translate ASCII quotes in messages and +help output. Its possible values and their semantics remain unchanged +from Emacs 25. In particular, when this variable's value is 'grave', +all quotes in formats are output as-is. + +--- +** Functions like 'check-declare-file' and 'check-declare-directory' +now generate less chatter and more-compact diagnostics. The auxiliary +function 'check-declare-errmsg' has been removed. + ++++ +** The regular expression character class '[:blank:]' now matches +Unicode horizontal whitespace as defined in the Unicode Technical +Standard #18. If you only want to match space and tab, use '[ \t]' +instead. + ++++ +** 'min' and 'max' no longer round their results. +Formerly, they returned a floating-point value if any argument was +floating-point, which was sometimes numerically incorrect. For +example, on a 64-bit host (max 1e16 10000000000000001) now returns its +second argument instead of its first. + ++++ +** The variable 'old-style-backquotes' has been made internal and +renamed to 'lread--old-style-backquotes'. No user code should use +this variable. + ++++ +** 'default-file-name-coding-system' now defaults to a coding system +that does not process CRLF. For example, it defaults to 'utf-8-unix' +instead of to 'utf-8'. Before this change, Emacs would sometimes +mishandle file names containing these control characters. + ++++ +** 'file-attributes', 'file-symlink-p' and 'make-symbolic-link' no +longer quietly mutate the target of a local symbolic link, so that +Emacs can access and copy them reliably regardless of their contents. +The following changes are involved. + +--- +*** 'file-attributes' and 'file-symlink-p' no longer prepend "/:" to +symbolic links whose targets begin with "/" and contain ":". For +example, if a symbolic link "x" has a target "/y:z:", '(file-symlink-p +"x")' now returns "/y:z:" rather than "/:/y:z:". + +--- +*** 'make-symbolic-link' no longer looks for file name handlers of +target when creating a symbolic link. For example, +'(make-symbolic-link "/y:z:" "x")' now creates a symbolic link to +"/y:z:" instead of failing. + ++++ +*** 'make-symbolic-link' removes the remote part of a link target if +target and newname have the same remote part. For example, +'(make-symbolic-link "/x:y:a" "/x:y:b")' creates a link with the +literal string "a"; and '(make-symbolic-link "/x:y:a" "/x:z:b")' +creates a link with the literal string "/x:y:a" instead of failing. + ++++ +*** 'make-symbolic-link' now expands a link target with leading "~" +only when the optional third arg is an integer, as when invoked +interactively. For example, '(make-symbolic-link "~y" "x")' now +creates a link with target the literal string "~y"; to get the old +behavior, use '(make-symbolic-link (expand-file-name "~y") "x")'. To +avoid this expansion in interactive use, you can now prefix the link +target with "/:". For example, '(make-symbolic-link "/:~y" "x" 1)' +now creates a link to literal "~y". + ++++ +** 'file-truename' returns a quoted file name if the target of a +symbolic link has remote file name syntax. + ++++ +** Module functions are now implemented slightly differently; in +particular, the function 'internal--module-call' has been removed. +Code that depends on undocumented internals of the module system might +break. + +--- +** The argument LOCKNAME of 'write-region' is propagated to file name +handlers now. + +--- +** When built against recent versions of GTK+, Emacs always uses +gtk_window_move for moving frames and ignores the value of the +variable 'x-gtk-use-window-move'. The variable is now obsolete. + ++++ +** Several functions that create or rename files now treat their +destination argument specially only when it is a directory name, i.e., +when it ends in '/' on GNU and other POSIX-like systems. When the +destination argument D of one of these functions is an existing +directory and the intent is to act on an entry in that directory, D +should now be a directory name. For example, (rename-file "e" "f/") +renames to 'f/e'. Although this formerly happened sometimes even when +D was not a directory name, as in (rename-file "e" "f") where 'f' +happened to be a directory, the old behavior often contradicted the +documentation and had inherent races that led to security holes. A +call like (rename-file C D) that used the old, undocumented behavior +can be written as (rename-file C (file-name-as-directory D)), a +formulation portable to both older and newer versions of Emacs. +Affected functions include 'add-name-to-file', 'copy-directory', +'copy-file', 'format-write-file', 'gnus-copy-file', +'make-symbolic-link', 'rename-file', 'thumbs-rename-images', and +'write-file'. + +--- +** The list returned by 'overlays-at' is now in decreasing priority order. +The documentation of this function always said the order should be +that of decreasing priority, if the 2nd argument of the function is +non-nil, but the code returned the list in the increasing order of +priority instead. Now the code does what the documentation says it +should do. + ++++ +** 'format' now avoids allocating a new string in more cases. +'format' was previously documented to return a newly-allocated string, +but this documentation was not correct, as (eq x (format x)) returned +t when x was the empty string. 'format' is no longer documented to +return a newly-allocated string, and the implementation now takes +advantage of the doc change to avoid making copies of strings in +common cases like (format "foo") and (format "%s" "foo"). + +--- +** 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. + +--- +** Using '&rest' or '&optional' incorrectly is now an error. +For example giving '&optional' without a following variable, or +passing '&optional' multiple times: + + (defun foo (&optional &rest x)) + (defun bar (&optional &optional x)) + +Previously, Emacs would just ignore the extra keyword, or give +incorrect results in certain cases. + +--- +** The pinentry.el library has been removed. +That package (and the corresponding change in GnuPG and pinentry) +was intended to provide a way to input passphrase through Emacs with +GnuPG 2.0. However, the change to support that was only implemented +in GnuPG >= 2.1 and didn't get backported to GnuPG 2.0. And with +GnuPG 2.1 and later, pinentry.el is not needed at all. So the +library was useless, and we removed it. GnuPG 2.0 is no longer +supported by the upstream project. + +To adapt to the change, you may need to set 'epa-pinentry-mode' to the +symbol 'loopback'. + +Note that previously, it was said that passphrase input through +minibuffer would be much less secure than other graphical pinentry +programs. However, these days the difference is insignificant: the +'read-password' function sufficiently protects input from leakage to +message logs. Emacs still doesn't use secure memory to protect +passphrases, but it was also removed from other pinentry programs as +the attack is unrealistic on modern computer systems which don't +utilize swap memory usually. + + +* Lisp Changes in Emacs 26.1 + ++++ +** The function 'assoc' now takes an optional third argument TESTFN. +This argument, when non-nil, is used for comparison instead of +'equal'. + ++++ +** New optional argument TESTFN in 'alist-get', 'map-elt' and 'map-put'. +If non-nil, the argument specifies a function to use for comparison, +instead of, respectively, 'assq' and 'eql'. + ++++ +** New function 'seq-set-equal-p' to check if SEQUENCE1 and SEQUENCE2 +contain the same elements, regardless of the order. + ++++ +** The new function 'mapbacktrace' applies a function to all frames of +the current stack trace. + ++++ +** The new function 'file-name-case-insensitive-p' tests whether a +given file is on a case-insensitive filesystem. + ++++ +** Several accessors for the value returned by 'file-attributes' +have been added. They are: 'file-attribute-type', +'file-attribute-link-number', 'file-attribute-user-id', +'file-attribute-group-id', 'file-attribute-access-time', +'file-attribute-modification-time', +'file-attribute-status-change-time', 'file-attribute-size', +'file-attribute-modes', 'file-attribute-inode-number', +'file-attribute-device-number' and 'file-attribute-collect'. + ++++ +** The new function 'buffer-hash' computes a fast, non-consing hash of +a buffer's contents. + ++++ +** 'interrupt-process' now consults the list 'interrupt-process-functions', +to determine which function has to be called in order to deliver the +SIGINT signal. This allows Tramp to send the SIGINT signal to remote +asynchronous processes. The hitherto existing implementation has been +moved to 'internal-default-interrupt-process'. + ++++ +** The new function 'read-multiple-choice' prompts for multiple-choice +questions, with a handy way to display help texts. + +--- +** 'comment-indent-function' values may now return a cons to specify a +range of indentation. + ++++ +** New optional argument TEXT in 'make-temp-file'. + +--- +** New function 'define-symbol-prop'. + ++++ +** New function 'secure-hash-algorithms' to list the algorithms that +'secure-hash' supports. +See the node "(elisp) Checksum/Hash" in the ELisp manual for details. + ++++ +** Emacs now exposes the GnuTLS cryptographic API with the functions +'gnutls-macs' and 'gnutls-hash-mac'; 'gnutls-digests' and +'gnutls-hash-digest'; 'gnutls-ciphers' and 'gnutls-symmetric-encrypt' +and 'gnutls-symmetric-decrypt'. +See the node "(elisp) GnuTLS Cryptography" in the ELisp manual for details. + ++++ +** The function 'gnutls-available-p' now returns a list of capabilities +supported by the GnuTLS library used by Emacs. + ++++ +** Emacs now supports records for user-defined types, via the new +functions 'make-record', 'record', and 'recordp'. Records are now +used internally to represent cl-defstruct and defclass instances, for +example. + +If your program defines new record types, you should use +package-naming conventions for naming those types. This is so any +potential conflicts with other types are avoided. + ++++ +** 'save-some-buffers' now uses 'save-some-buffers-default-predicate' +to decide which buffers to ask about, if the PRED argument is nil. +The default value of 'save-some-buffers-default-predicate' is nil, +which means ask about all file-visiting buffers. + +--- +** string-(to|as|make)-(uni|multi)byte are now declared obsolete. + ++++ +** New variable 'while-no-input-ignore-events' which allow +setting which special events 'while-no-input' should ignore. +It is a list of symbols. + +--- +** New function 'undo-amalgamate-change-group' to get rid of +undo-boundaries between two states. + +--- +** New var 'definition-prefixes' is a hash table mapping prefixes to +the files where corresponding definitions can be found. This can be +used to fetch definitions that are not yet loaded, for example for +'C-h f'. + +--- +** New var 'syntax-ppss-table' to control the syntax-table used in +'syntax-ppss'. + ++++ +** 'define-derived-mode' can now specify an :after-hook form, which +gets evaluated after the new mode's hook has run. This can be used to +incorporate configuration changes made in the mode hook into the +mode's setup. + +--- +** Autoload files can be generated without timestamps, +by setting 'autoload-timestamps' to nil. +FIXME As an experiment, nil is the current default. +If no insurmountable problems before next release, it can stay that way. + +--- +** 'gnutls-boot' now takes a parameter ':complete-negotiation' that +says that negotiation should complete even on non-blocking sockets. + +--- +** There is now a new variable 'flyspell-sort-corrections-function' +that allows changing the way corrections are sorted. + +--- +** The new command 'fortune-message' has been added, which displays +fortunes in the echo area. + ++++ +** New function 'func-arity' returns information about the argument list +of an arbitrary function. This generalizes 'subr-arity' for functions +that are not built-in primitives. We recommend using this new +function instead of 'subr-arity'. + +--- +** New function 'region-bounds' can be used in the interactive spec +to provide region boundaries (for rectangular regions more than one) +to an interactively callable function as a single argument instead of +two separate arguments 'region-beginning' and 'region-end'. + ++++ +** 'parse-partial-sexp' state has a new element. Element 10 is +non-nil when the last character scanned might be the first character +of a two character construct, i.e., a comment delimiter or escaped +character. Its value is the syntax of that last character. + ++++ +** 'parse-partial-sexp's state, element 9, has now been confirmed as +permanent and documented, and may be used by Lisp programs. Its value +is a list of currently open parenthesis positions, starting with the +outermost parenthesis. + +--- +** 'read-color' will now display the color names using the color itself +as the background color. + +--- +** The function 'redirect-debugging-output' now works on platforms +other than GNU/Linux. + ++++ +** The new function 'string-version-lessp' compares strings by +interpreting consecutive runs of numerical characters as numbers, and +compares their numerical values. According to this predicate, +"foo2.png" is smaller than "foo12.png". + +--- +** Numeric comparisons and 'logb' no longer return incorrect answers +due to internal rounding errors. For example, '(< most-positive-fixnum +(+ 1.0 most-positive-fixnum))' now correctly returns t on 64-bit hosts. + +--- +** The functions 'ffloor', 'fceiling', 'ftruncate' and 'fround' now +accept only floating-point arguments, as per their documentation. +Formerly, they quietly accepted integer arguments and sometimes +returned nonsensical answers, e.g., '(< N (ffloor N))' could return t. + +--- +** On hosts like GNU/Linux x86-64 where a 'long double' fraction +contains at least EMACS_INT_WIDTH - 3 bits, 'format' no longer returns +incorrect answers due to internal rounding errors when formatting +Emacs integers with '%e', '%f', or '%g' conversions. For example, on +these hosts '(eql N (string-to-number (format "%.0f" N)))' now returns +t for all Emacs integers N. + +--- +** Calls that accept floating-point integers (for use on hosts with +limited integer range) now signal an error if arguments are not +integral. For example '(decode-char 'ascii 0.5)' now signals an error. + ++++ +** The new function 'char-from-name' converts a Unicode name string +to the corresponding character code. + ++++ +** New functions 'sxhash-eq' and 'sxhash-eql' return hash codes of a +Lisp object suitable for use with 'eq' and 'eql' correspondingly. If +two objects are 'eq' ('eql'), then the result of 'sxhash-eq' +('sxhash-eql') on them will be the same. + ++++ +** Function 'sxhash' has been renamed to 'sxhash-equal' for +consistency with the new functions. For compatibility, 'sxhash' +remains as an alias to 'sxhash-equal'. + ++++ +** 'make-hash-table' now defaults to a rehash threshold of 0.8125 +instead of 0.8, to avoid rounding glitches. + ++++ +** New function 'add-variable-watcher' can be used to call a function +when a symbol's value is changed. This is used to implement the new +debugger command 'debug-on-variable-change'. + ++++ +** Time conversion functions that accept a time zone rule argument now +allow it to be OFFSET or a list (OFFSET ABBR), where the integer +OFFSET is a count of seconds east of Universal Time, and the string +ABBR is a time zone abbreviation. The affected functions are +'current-time-string', 'current-time-zone', 'decode-time', +'format-time-string', and 'set-time-zone-rule'. + ++++ +** 'format-time-string' now formats '%q' to the calendar quarter. + ++++ +** New built-in function 'mapcan'. +It avoids unnecessary consing (and garbage collection). + ++++ +** 'car' and 'cdr' compositions 'cXXXr' and 'cXXXXr' are now part of Elisp. + ++++ +** 'gensym' is now part of Elisp. + +--- +** Low-level list functions like 'length' and 'member' now do a better +job of signaling list cycles instead of looping indefinitely. + ++++ +** The new functions 'make-nearby-temp-file' and 'temporary-file-directory' +can be used for creation of temporary files on remote or mounted directories. + ++++ +** On GNU platforms when operating on a local file, 'file-attributes' +no longer suffers from a race when called while another process is +altering the filesystem. On non-GNU platforms 'file-attributes' +attempts to detect the race, and returns nil if it does so. + ++++ +** The new function 'file-local-name' can be used to specify arguments +of remote processes. + ++++ +** The new functions 'file-name-quote', 'file-name-unquote' and +'file-name-quoted-p' can be used to quote / unquote file names with +the prefix "/:". + ++++ +** The new error 'file-missing', a subcategory of 'file-error', is now +signaled instead of 'file-error' if a file operation acts on a file +that does not exist. + ++++ +** The function 'delete-directory' no longer signals an error when +operating recursively and when some other process deletes the directory +or its files before 'delete-directory' gets to them. + ++++ +** New error type 'user-search-failed' like 'search-failed' but +avoids debugger like 'user-error'. + ++++ +** The function 'line-number-at-pos' now takes a second optional +argument 'absolute'. If this parameter is nil, the default, this +function keeps on returning the line number taking potential narrowing +into account. If this parameter is non-nil, the function ignores +narrowing and returns the absolute line number. + +--- +** The function 'color-distance' now takes a second optional argument +'metric'. When non-nil, it should be a function of two arguments that +accepts two colors and returns a number. + +** Changes in Frame and Window Handling + ++++ +*** Resizing a frame no longer runs 'window-configuration-change-hook'. +'window-size-change-functions' should be used instead. + ++++ +*** The new function 'frame-size-changed-p' can tell whether a frame has +been resized since the last time 'window-size-change-functions' has been +run. + ++++ +*** The function 'frame-geometry' now also returns the width of a +frame's outer border. + ++++ +*** New frame parameters and changed semantics for older ones: + ++++ +**** 'z-group' positions a frame above or below all others. + ++++ +**** 'min-width' and 'min-height' specify the absolute minimum size of a +frame. + ++++ +**** 'parent-frame' makes a frame the child frame of another Emacs +frame. The section "(elisp) Child Frames" in the ELisp manual +describes the intrinsics of that relationship. + ++++ +**** 'delete-before' triggers deletion of one frame before that of +another. + ++++ +**** 'mouse-wheel-frame' specifies another frame whose windows shall be +scrolled instead. + ++++ +**** 'no-other-frame' has 'next-frame' and 'previous-frame' skip this +frame. + ++++ +**** 'skip-taskbar' removes a frame's icon from the taskbar and has +'Alt-<TAB>' skip this frame. + ++++ +**** 'no-focus-on-map' avoids that a frame gets input focus when mapped. + ++++ +**** 'no-accept-focus' means that a frame does not want to get input +focus via the mouse. + ++++ +**** 'undecorated' removes the window manager decorations from a frame. + ++++ +**** 'override-redirect' tells the window manager to disregard this +frame. + ++++ +**** 'width' and 'height' now allow the specification of pixel values +and ratios. + ++++ +**** 'left' and 'top' now allow the specification of ratios. + ++++ +**** 'keep-ratio' preserves size and position of child frames when their +parent frame is resized. + ++++ +**** 'no-special-glyphs' suppresses display of truncation and +continuation glyphs in a frame. + ++++ +**** 'auto-hide-function' and 'minibuffer-exit' handle auto hiding of +frames and exiting from minibuffer individually. + ++++ +**** 'fit-frame-to-buffer-margins' and 'fit-frame-to-buffer-sizes' +handle fitting a frame to its buffer individually. + ++++ +**** 'drag-internal-border', 'drag-with-header-line', +'drag-with-mode-line', 'snap-width', 'top-visible' and 'bottom-visible' +allow dragging and resizing frames with the mouse. + ++++ +**** 'minibuffer' is now set to the default minibuffer window when +initially specified as nil and is not reset to nil when initially +specifying a minibuffer window. + +*** The new function 'frame-list-z-order' returns a list of all frames +in Z (stacking) order. + ++++ +*** The function 'x-focus-frame' optionally tries to not activate its +frame. + ++++ +*** The variable 'focus-follows-mouse' has a third meaningful value +'auto-raise' to indicate that the window manager automatically raises a +frame when the mouse pointer enters it. + ++++ +*** The new function 'frame-restack' puts a frame above or below +another on the display. + ++++ +*** The new face 'internal-border' specifies the background of a frame's +internal border. + ++++ +*** The NORECORD argument of 'select-window' now has a meaningful value +'mark-for-redisplay' which is like any other non-nil value but marks +WINDOW for redisplay. + ++++ +*** Support for side windows is now official. The display action +function 'display-buffer-in-side-window' will display its buffer in a +side window. Functions for toggling all side windows on a frame, +changing and reversing the layout of side windows and returning the +main (major non-side) window of a frame are provided. For details +consult the section "(elisp) Side Windows" in the ELisp manual. + ++++ +*** Support for atomic windows - rectangular compositions of windows +treated by 'split-window', 'delete-window' and 'delete-other-windows' +like a single live window - is now official. For details consult the +section "(elisp) Atomic Windows" in the ELisp manual. + ++++ +*** New 'display-buffer' alist entry 'window-parameters' allows the +assignment of window parameters to the window used for displaying the +buffer. + ++++ +*** New function 'display-buffer-reuse-mode-window' is an action function +suitable for use in 'display-buffer-alist'. For example, to avoid +creating a new window when opening man pages when there's already one, +use + +(add-to-list 'display-buffer-alist + '("\\`\\*Man .*\\*\\'" . + (display-buffer-reuse-mode-window + (inhibit-same-window . nil) + (mode . Man-mode)))) + ++++ +*** New window parameter 'no-delete-other-windows' prevents that +its window gets deleted by 'delete-other-windows'. + ++++ +*** New window parameters 'mode-line-format' and 'header-line-format' +allow the buffer-local formats for this window to be overridden. + ++++ +*** New command 'window-swap-states' swaps the states of two live +windows. + ++++ +*** New functions 'window-pixel-width-before-size-change' and +'window-pixel-height-before-size-change' support detecting which +window changed size when 'window-size-change-functions' are run. + ++++ +*** The new function 'window-lines-pixel-dimensions' returns the pixel +dimensions of a window's text lines. + ++++ +*** The new function 'window-largest-empty-rectangle' returns the +dimensions of the largest rectangular area not occupying any text in a +window's body. + ++++ +*** The semantics of 'mouse-autoselect-window' has changed slightly. +For details see the section "(elisp) Mouse Window Auto-selection" in +the ELisp manual. + +--- +*** 'select-frame-by-name' now may return a frame on another display +if it does not find a suitable one on the current display. + +--- +** 'tcl-auto-fill-mode' is now declared obsolete. Its functionality +can be replicated simply by setting 'comment-auto-fill-only-comments'. + +** New pcase pattern 'rx' to match against an rx-style regular expression. +For details, see the doc string of 'rx--pcase-macroexpander'. + +--- +** New functions to set region from secondary selection and vice versa. +The new functions 'secondary-selection-to-region' and +'secondary-selection-from-region' let you set the beginning and the +end of the region from those of the secondary selection and vice +versa. + +** New function 'lgstring-remove-glyph' can be used to modify a +gstring returned by the underlying layout engine (e.g. m17n-flt, +uniscribe). + + +* Changes in Emacs 26.1 on Non-Free Operating Systems + ++++ +** Intercepting hotkeys on Windows 7 and later now works better. +The new keyboard hooking code properly grabs system hotkeys such as +'Win-*' and 'Alt-TAB', in a way that Emacs can get at them before the +system. This makes the 'w32-register-hot-key' functionality work +again on all versions of MS-Windows starting with Windows 7. On +Windows NT and later you can now register any hotkey combination. (On +Windows 9X, the previous limitations, spelled out in the Emacs manual, +still apply.) + +--- +** 'convert-standard-filename' no longer mirrors slashes on MS-Windows. +Previously, on MS-Windows this function converted slash characters in +file names into backslashes. It no longer does that. If your Lisp +program used 'convert-standard-filename' to prepare file names to be +passed to subprocesses (which is not the recommended usage of that +function), you will now have to mirror slashes in your application +code. One possible way is this: + + (let ((start 0)) + (while (string-match "/" file-name start) + (aset file-name (match-beginning 0) ?\\) + (setq start (match-end 0)))) + +--- +** GUI sessions on MS-Windows now treat SIGINT like Posix platforms do. +The effect of delivering a Ctrl-C (SIGINT) signal to a GUI Emacs on +MS-Windows is now the same as on Posix platforms -- Emacs saves the +session and exits. In particular, this will happen if you start +emacs.exe from the Windows shell, then type Ctrl-C into that shell's +window. + +--- +** 'signal-process' supports SIGTRAP on Windows XP and later. +The 'kill' emulation on Windows now maps SIGTRAP to a call to the +'DebugBreakProcess' API. This causes the receiving process to break +execution and return control to the debugger. If no debugger is +attached to the receiving process, the call is typically ignored. +This is in contrast to the default action on POSIX Systems, where it +causes the receiving process to terminate with a core dump if no +debugger has been attached to it. + +--- +** 'set-mouse-position' and 'set-mouse-absolute-pixel-position' work +on macOS. + +--- +** Emacs can now be run as a GUI application from the command line on +macOS. + ++++ +** 'ns-appearance' and 'ns-transparent-titlebar' change the appearance +of frame decorations on macOS 10.9+. + +--- +** 'ns-use-thin-smoothing' enables thin font smoothing on macOS 10.8+. + +--- +** 'process-attributes' on Darwin systems now returns more information. + +--- +** Mousewheel and trackpad scrolling on macOS 10.7+ now behaves more +like the macOS default. The new variables 'ns-mwheel-line-height', +'ns-use-mwheel-acceleration' and 'ns-use-mwheel-momentum' can be used +to customize the behavior. + + +---------------------------------------------------------------------- +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: |