1 GNU Emacs NEWS -- history of user-visible changes.
3 Copyright (C) 2014-2016 Free Software Foundation, Inc.
4 See the end of the file for license conditions.
6 Please send Emacs bug reports to bug-gnu-emacs@gnu.org.
7 If possible, use M-x report-emacs-bug.
9 This file is about changes in Emacs version 26.
11 See file HISTORY for a list of GNU Emacs versions and release dates.
12 See files NEWS.25, NEWS.24, NEWS.23, NEWS.22, NEWS.21, NEWS.20,
13 NEWS.19, NEWS.18, and NEWS.1-17 for changes in older Emacs versions.
15 You can narrow news to a specific version by calling 'view-emacs-news'
16 with a prefix argument or by typing C-u C-h C-n.
19 +++ indicates that all necessary documentation updates are complete.
20 (This means all relevant manuals in doc/ AND lisp doc-strings.)
21 --- means no change in the manuals is needed.
22 When you add a new item, use the appropriate mark if you are sure it applies,
25 * Installation Changes in Emacs 26.1
27 ** By default libgnutls is now required when building Emacs.
28 Use 'configure --with-gnutls=no' to build even when GnuTLS is missing.
30 ** GnuTLS version 2.12.2 or later is now required, instead of merely
31 version 2.6.6 or later.
33 ** The new option 'configure --enable-gcc-warnings=warn-only' causes
34 GCC to issue warnings without stopping the build. This behavior is
35 now the default in developer builds. As before, use
36 '--disable-gcc-warnings' to suppress GCC's warnings, and
37 '--enable-gcc-warnings' to stop the build if GCC issues warnings.
40 ** The Emacs server now has socket-launching support. This allows
41 socket based activation, where an external process like systemd can
42 invoke the Emacs server process upon a socket connection event and
43 hand the socket over to Emacs. Emacs uses this socket to service
44 emacsclient commands. This new functionality can be disabled with the
45 configure option '--disable-libsystemd'.
48 ** A systemd user unit file is provided. Use it in the standard way:
49 systemctl --user enable emacs
50 (If your Emacs is installed in a non-standard location, you may
51 need to copy the emacs.service file to eg ~/.config/systemd/user/)
53 ** New configure option '--disable-build-details' attempts to build an
54 Emacs that is more likely to be reproducible; that is, if you build
55 and install Emacs twice, the second Emacs is a copy of the first.
56 Deterministic builds omit the build date from the output of the
57 emacs-version and erc-cmd-SV functions, and the leave the following
58 variables nil: emacs-build-system, emacs-build-time,
61 ** Emacs no longer works on IRIX. We expect that Emacs users are not
62 affected by this, as SGI stopped supporting IRIX in December 2013.
65 * Startup Changes in Emacs 26.1
67 ** New option '--new-daemon'. This is the same as '--daemon', except
68 it runs in the foreground and does not fork. This is intended for
69 modern init systems such as systemd, which manage many of the traditional
70 aspects of daemon behavior themselves. '--old-daemon' is now an alias
74 * Changes in Emacs 26.1
77 ** The new function 'mapbacktrace' applies a function to all frames of
78 the current stack trace.
81 ** Emacs now provides a limited form of concurrency with Lisp threads.
82 Concurrency in Emacs Lisp is "mostly cooperative", meaning that
83 Emacs will only switch execution between threads at well-defined
84 times: when Emacs waits for input, during blocking operations related
85 to threads (such as mutex locking), or when the current thread
86 explicitly yields. Global variables are shared among all threads, but
87 a 'let' binding is thread-local. Each thread also has its own current
88 buffer and its own match data.
90 See the chapter "Threads" in the ELisp manual for full documentation
94 ** The new function 'file-name-case-insensitive-p' tests whether a
95 given file is on a case-insensitive filesystem.
98 ** The new user variable 'electric-quote-chars' provides a list
99 of curved quotes for 'electric-quote-mode', allowing user to choose
100 the types of quotes to be used.
103 ** The new user variable 'dired-omit-case-fold' allows the user to
104 customize the case-sensitivity of dired-omit-mode. It defaults to
105 the same sensitivity as that of the filesystem for the corresponding
109 ** Emacs now uses double buffering to reduce flicker when editing and
110 resizing graphical Emacs frames on the X Window System. This support
111 requires the DOUBLE-BUFFER extension, which major X servers have
112 supported for many years.
115 The group 'wp', whose label was "text", is now deprecated.
116 Use the new group 'text', which inherits from 'wp', instead.
119 ** The new function 'call-shell-region' executes a command in an
120 inferior shell with the buffer region as input.
123 ** The new user option 'shell-command-dont-erase-buffer' controls
124 if the output buffer is erased between shell commands; if non-nil,
125 the output buffer is not erased; this variable also controls where
126 to set the point in the output buffer: beginning of the output,
127 end of the buffer or save the point.
128 When 'shell-command-dont-erase-buffer' is nil, the default value,
129 the behavior of 'shell-command', 'shell-command-on-region' and
130 'async-shell-command' is as usual.
133 ** The new user option 'mouse-select-region-move-to-beginning'
134 controls the position of point when double-clicking mouse-1 on the end
135 of a parenthetical grouping or string-delimiter: the default value nil
136 keeps point at the end of the region, setting it to non-nil moves
137 point to the beginning of the region.
140 ** The new user option 'confirm-kill-processes' allows the user to
141 skip a confirmation prompt for killing subprocesses when exiting
142 Emacs. When set to t (the default), Emacs will prompt for
143 confirmation before killing subprocesses on exit, which is the same
147 ** 'find-library-name' will now fall back on looking at 'load-history'
148 to try to locate libraries that have been loaded with an explicit path
152 ** Faces in 'minibuffer-prompt-properties' no longer overwrite properties
153 in the text in functions like 'read-from-minibuffer', but instead are
154 added to the end of the face list. This allows users to say things
155 like '(read-from-minibuffer (propertize "Enter something: " 'face 'bold))'.
158 ** The new variable 'extended-command-suggest-shorter' has been added
159 to control whether to suggest shorter 'M-x' commands or not.
162 ** icomplete now respects 'completion-ignored-extensions'.
165 ** Non-breaking hyphens are now displayed with the 'nobreak-hyphen'
166 face instead of the 'escape-glyph' face.
169 ** Approximations to quotes are now displayed with the new 'homoglyph'
170 face instead of the 'escape-glyph' face.
173 ** 'C-x h' ('mark-whole-buffer') will now avoid marking the prompt
177 ** 'find-library' now takes a prefix argument to pop to a different
181 ** 'process-attributes' on Darwin systems now returns more information.
184 ** Several accessors for the value returned by 'file-attributes'
185 have been added. They are: 'file-attribute-type',
186 'file-attribute-link-number', 'file-attribute-user-id',
187 'file-attribute-group-id', 'file-attribute-access-time',
188 'file-attribute-modification-time',
189 'file-attribute-status-change-time', 'file-attribute-size',
190 'file-attribute-modes', 'file-attribute-inode-number',
191 'file-attribute-device-number' and 'file-attribute-collect'.
194 ** The new function 'buffer-hash' computes a fast, non-consing hash of
198 ** 'fill-paragraph' no longer marks the buffer as changed unless it
199 actually changed something.
202 ** The locale language name 'ca' is now mapped to the language
203 environment 'Catalan', which has been added.
206 ** 'align-regexp' has a separate history for its interactive argument.
207 'align-regexp' no longer shares its history with all other
208 history-less functions that use 'read-string'.
211 ** The networking code has been reworked so that it's more
212 asynchronous than it was (when specifying :nowait t in
213 'make-network-process'). How asynchronous it is varies based on the
214 capabilities of the system, but on a typical GNU/Linux system the DNS
215 resolution, the connection, and (for TLS streams) the TLS negotiation
216 are all done without blocking the main Emacs thread. To get
217 asynchronous TLS, the TLS boot parameters have to be passed in (see
218 the manual for details).
220 Certain process oriented functions (like 'process-datagram-address')
221 will block until socket setup has been performed. The recommended way
222 to deal with asynchronous sockets is to avoid interacting with them
223 until they have changed status to "run". This is most easily done
224 from a process sentinel.
226 ** 'make-network-process' and 'open-network-stream' sometimes allowed
227 :service to be an integer string (e.g., :service "993") and sometimes
228 required an integer (e.g., :service 993). This difference has been
229 eliminated, and integer strings work everywhere.
231 ** It is possible to disable attempted recovery on fatal signals.
233 Two new variables support disabling attempts to recover from stack
234 overflow and to avoid automatic auto-save when Emacs is delivered a
235 fatal signal. 'attempt-stack-overflow-recovery', if set to 'nil',
236 will disable attempts to recover from C stack overflows; Emacs will
237 then crash as with any other fatal signal.
238 'attempt-orderly-shutdown-on-fatal-signal', if set to 'nil', will
239 disable attempts to auto-save the session and shut down in an orderly
240 fashion when Emacs receives a fatal signal; instead, Emacs will
241 terminate immediately. Both variables are non-'nil' by default.
242 These variables are for users who would like to avoid the small
243 probability of data corruption due to techniques Emacs uses to recover
247 ** File local and directory local variables are now initialized each
248 time the major mode is set, not just when the file is first visited.
249 These local variables will thus not vanish on setting a major mode.
252 ** A second dir-local file (.dir-locals-2.el) is now accepted.
253 See the variable 'dir-locals-file-2' for more information.
256 ** Connection-local variables can be used to specify local variables
257 with a value depending on the connected remote server. For details,
258 see the node "Connection Local Variables" in the ELisp manual.
261 ** International domain names (IDNA) are now encoded via the new
262 puny.el library, so that one can visit web sites with non-ASCII URLs.
265 ** The new 'timer-list' command lists all active timers in a buffer,
266 where you can cancel them with the 'c' command.
269 ** The new function 'read-multiple-choice' prompts for multiple-choice
270 questions, with a handy way to display help texts.
273 ** 'switch-to-buffer-preserve-window-point' now defaults to t.
276 ** The new variable 'debugger-stack-frame-as-list' allows displaying
277 all call stack frames in a Lisp backtrace buffer as lists. Both
278 debug.el and edebug.el have been updated to heed to this variable.
281 ** The new variable 'x-ctrl-keysym' has been added to the existing
282 roster of X keysyms. It can be used in combination with another
283 variable of this kind to swap modifiers in Emacs.
286 ** New input methods: 'cyrillic-tuvan', 'polish-prefix'.
289 ** File name quoting by adding the prefix "/:" is now possible for the
290 local part of a remote file name. Thus, if you have a directory named
291 "/~" on the remote host "foo", you can prevent it from being
292 substituted by a home directory by writing it as "/foo:/:/~/file".
295 * Editing Changes in Emacs 26.1
298 ** New bindings for 'query-replace-map'.
299 'undo', undo the last replacement; bound to 'u'.
300 'undo-all', undo all replacements; bound to 'U'.
302 ** 'delete-trailing-whitespace' deletes whitespace after form feed.
303 In modes where form feed was treated as a whitespace character,
304 'delete-trailing-whitespace' would keep lines containing it unchanged.
305 It now deletes whitespace after the last form feed thus behaving the
306 same as in modes where the character is not whitespace.
308 ** No more prompt about changed file when the file's content is unchanged.
309 Instead of only checking the modification time, Emacs now also checks
310 the file's actual content before prompting the user.
313 * Changes in Specialized Modes and Packages in Emacs 26.1
315 ** TeX: Add luatex and xetex as alternatives to pdftex
317 ** Electric-Buffer-menu
320 *** Key 'U' is bound to 'Buffer-menu-unmark-all' and key 'M-DEL' is
321 bound to 'Buffer-menu-unmark-all-buffers'.
326 *** Two new commands 'bs-unmark-all', bound to 'U', and
327 'bs-unmark-previous', bound to <backspace>.
332 *** Two new commands 'Buffer-menu-unmark-all', bound to 'U' and
333 'Buffer-menu-unmark-all-buffers', bound to 'M-DEL'.
338 *** New filter commands `ibuffer-filter-by-basename',
339 `ibuffer-filter-by-file-extension', `ibuffer-filter-by-directory',
340 `ibuffer-filter-by-starred-name', `ibuffer-filter-by-modified'
341 and `ibuffer-filter-by-visiting-file'; bound respectively
342 to '/b', '/.', '//', '/*', '/i' and '/v'.
345 *** Two new commands 'ibuffer-filter-chosen-by-completion'
346 and `ibuffer-and-filter', the second bound to '/&'.
349 *** The commands `ibuffer-pop-filter', `ibuffer-pop-filter-group',
350 `ibuffer-or-filter' and `ibuffer-filter-disable' have the alternative
351 bindings '/<up>', '/S-<up>', '/|' and '/DEL', respectively.
354 *** The data format specifying filters has been extended to allow
355 explicit logical 'and', and a more flexible form for logical 'not'.
356 See 'ibuffer-filtering-qualifiers' doc string for full details.
359 *** A new command 'ibuffer-copy-buffername-as-kill'; bound
363 *** New command 'ibuffer-change-marks'; bound to '* c'.
366 *** A new command 'ibuffer-mark-by-locked' to mark
367 all locked buffers; bound to '% L'.
370 *** A new option 'ibuffer-locked-char' to indicate
371 locked buffers; Ibuffer shows a new column displaying
372 'ibuffer-locked-char' for locked buffers.
375 *** A new command 'ibuffer-unmark-all-marks' to unmark
376 all buffers without asking confirmation; bound to
377 'U'; 'ibuffer-do-replace-regexp' bound to 'r'.
380 *** A new command 'ibuffer-mark-by-content-regexp' to mark buffers
381 whose content matches a regexp; bound to '% g'.
384 *** Two new options 'ibuffer-never-search-content-name' and
385 'ibuffer-never-search-content-mode' used by
386 'ibuffer-mark-by-content-regexp'.
390 *** Support for opening links to man pages in Man or WoMan mode.
395 *** New user option 'comint-move-point-for-matching-input' to control
396 where to place point after C-c M-r and C-c M-s.
401 *** Messages from CMake are now recognized.
406 *** A new option 'dired-always-read-filesystem' default to nil.
407 If non-nil, buffers visiting files are reverted before search them;
408 for instance, in 'dired-mark-files-containing-regexp' a non-nil value
409 of this option means the file is revisited in a temporary buffer;
410 this temporary buffer is the actual buffer searched: the original buffer
411 visiting the file is not modified.
414 *** In wdired, when editing files to contain slash characters,
415 the resulting directories are automatically created. Whether to do
416 this is controlled by the 'wdired-create-parent-directories' variable.
419 *** 'W' is now bound to 'browse-url-of-dired-file', and is useful for
420 viewing HTML files and the like.
424 *** Edebug can be prevented from pausing 1 second after reaching a
425 breakpoint (e.g. with "f" and "o") by customizing the new option
426 'edebug-sit-on-break'.
430 *** 'eshell-input-filter's value is now a named function
431 'eshell-input-filter-default', and has a new custom option
432 'eshell-input-filter-initial-space' to ignore adding commands prefixed
433 with blank space to eshell history.
438 *** New 'M-RET' command for opening a link at point in a new eww buffer.
441 *** A new 's' command for switching to another eww buffer via the minibuffer.
444 *** The 'o' command ('shr-save-contents') has moved to 'O' to avoid collision
445 with the 'o' command from 'image-map'.
448 *** A new command 'C' ('eww-toggle-colors') can be used to toggle
449 whether to use the HTML-specified colors or not. The user can also
450 customize the 'shr-use-colors' variable.
453 *** Images that are being loaded are now marked with gray
454 "placeholder" images of the size specified by the HTML. They are then
455 replaced by the real images asynchronously, which will also now
456 respect width/height HTML specs (unless they specify widths/heights
457 bigger than the current window).
462 *** Images are automatically scaled before displaying based on the
463 'image-scaling-factor' variable (if Emacs supports scaling the images
467 *** Images inserted with 'insert-image' and related functions get a
468 keymap put into the text properties (or overlays) that span the
469 image. This keymap binds keystrokes for manipulating size and
470 rotation, as well as saving the image to a file. These commands are
471 also available in 'image-mode'.
474 *** A new library for creating and manipulating SVG images has been
475 added. See the "SVG Images" section in the Lisp reference manual for
479 *** New setf-able function to access and set image parameters is
480 provided: 'image-property'.
483 *** New commands 'image-scroll-left' and 'image-scroll-right'
484 for 'image-mode' that complement 'image-scroll-up' and
485 'image-scroll-down': they have the same prefix arg behavior and stop
490 *** Now provides a minor mode 'image-dired-minor-mode' which replaces
491 the function 'image-dired-setup-dired-keybindings'.
493 *** Thumbnail generation is now asynchronous
494 The number of concurrent processes is limited by the variable
495 'image-dired-thumb-job-limit'.
497 *** 'image-dired-thumbnail-storage' has a new option 'standard-large'
498 for generating 256x256 thumbnails according to the Thumbnail Managing
501 *** Inherits movement keys from 'image-mode' for viewing full images.
502 This includes the usual char, line, and page movement commands.
504 *** All the -options types have been changed to argument lists
505 instead of shell command strings. This change affects
506 'image-dired-cmd-create-thumbnail-options',
507 'image-dired-cmd-create-temp-image-options',
508 'image-dired-cmd-rotate-thumbnail-options',
509 'image-dired-cmd-rotate-original-options',
510 'image-dired-cmd-write-exif-data-options',
511 'image-dired-cmd-read-exif-data-options', and introduces
512 'image-dired-cmd-pngnq-options', 'image-dired-cmd-pngcrush-options',
513 'image-dired-cmd-create-standard-thumbnail-options'
515 *** Recognizes more tools by default, including pngnq-s9 and OptiPNG
517 *** 'find-file' and related commands now work on thumbnails and
518 displayed images, providing a default argument of the original file name
519 via an addition to 'file-name-at-point-functions'.
522 ** The default 'Info-default-directory-list' no longer checks some obsolete
523 directory suffixes (gnu, gnu/lib, gnu/lib/emacs, emacs, lib, lib/emacs)
524 when searching for info directories.
527 ** The commands that add ChangeLog entries now prefer a VCS root directory
528 for the ChangeLog file, if none already exists. Customize
529 'change-log-directory-files' to nil for the old behavior.
532 ** Support for non-string values of 'time-stamp-format' has been removed.
537 *** 'message-use-idna' now defaults to t (because Emacs comes with
538 built-in IDNA support now).
541 *** When sending HTML messages with embedded images, and you have
542 exiftool installed, and you rotate images with EXIF data (i.e.,
543 JPEGs), the rotational information will be inserted into the outgoing
544 image in the message. (The original image will not have its
545 orientation affected.)
548 *** The 'message-valid-fqdn-regexp' variable has been removed, since
549 there are now top-level domains added all the time. Message will no
550 longer warn about sending emails to top-level domains it hasn't heard
553 *** 'message-beginning-of-line' (bound to C-a) understands folded headers.
554 In 'visual-line-mode' it will look for the true beginning of a header
555 while in non-'visual-line-mode' it will move the point to the indented
561 *** New connection method "sg", which supports editing files under a
565 *** New connection method "doas" for OpenBSD hosts.
568 *** New connection method "gdrive", which allows to access Google
569 Drive onsite repositories.
572 *** Gateway methods in Tramp have been removed. Instead, the Tramp
573 manual documents how to configure ssh and PuTTY accordingly.
576 Setting the "ENV" environment variable in 'tramp-remote-process-environment'
577 enables reading of shell initialization files.
580 ** 'auto-revert-use-notify' is set back to t in 'global-auto-revert-mode'.
585 *** Support for completing attribute values, at-rules, bang-rules,
586 HTML tags, classes and IDs using the 'completion-at-point' command.
587 Completion candidates for HTML classes and IDs are retrieved from open
591 ** Emacs now supports character name escape sequences in character and
592 string literals. The syntax variants \N{character name} and
593 \N{U+code} are supported.
596 ** Prog mode has some support for multi-mode indentation.
597 This allows better indentation support in modes that support multiple
598 programming languages in the same buffer, like literate programming
599 environments or ANTLR programs with embedded Python code.
601 A major mode can provide indentation context for a sub-mode through
602 the 'prog-indentation-context' variable. To support this, modes that
603 provide indentation should use 'prog-widen' instead of 'widen' and
604 'prog-first-column' instead of a literal zero. See the node
605 "Mode-Specific Indent" in the ELisp manual for more details.
609 *** New variable 'erc-default-port-tls' used to connect to TLS IRC
615 *** The new function 'url-cookie-delete-cookie' can be used to
616 programmatically delete all cookies, or cookies from a specific
620 *** 'url-retrieve-synchronously' now takes an optional timeout parameter.
623 *** The URL package now support HTTPS over proxies supporting CONNECT.
626 *** 'url-user-agent' now defaults to 'default', and the User-Agent
627 string is computed dynamically based on 'url-privacy-level'.
629 ** VC and related modes
632 *** The VC state indicator in the mode line now defaults to more
633 colorful faces to make it more obvious to the user what the state is.
634 See the 'vc-faces' customization group.
638 *** Opening a .h file will turn C or C++ mode depending on language used.
639 This is done with the help of 'c-or-c++-mode' function which analyses
640 contents of the buffer to determine whether it's a C or C++ source
646 *** Emacs does no longer prompt the user before killing Flymake
650 * New Modes and Packages in Emacs 26.1
652 ** New Elisp data-structure library 'radix-tree'.
655 * Incompatible Lisp Changes in Emacs 26.1
658 ** Resizing a frame no longer runs 'window-configuration-change-hook'.
659 Put your function on 'window-size-change-functions' instead.
661 ** 'C-up', 'C-down', 'C-left' and 'C-right' are now defined in term
662 mode to send the same escape sequences that xterm does. This makes
663 things like forward-word in readline work.
666 ** hideshow mode got four key bindings that are analogous to outline
667 mode bindings: 'C-c @ C-a', 'C-c @ C-t', 'C-c @ C-d', and 'C-c @ C-e.'
669 ** The grep/rgrep/lgrep functions will now ask about saving files
670 before running. This is controlled by the 'grep-save-buffers'
673 ** Some obsolete functions, variables, and faces have been removed:
674 *** make-variable-frame-local. Variables cannot be frame-local any more.
675 *** From subr.el: window-dot, set-window-dot, read-input, show-buffer,
676 eval-current-buffer, string-to-int
677 *** All the default-FOO variables that hold the default value of the
678 FOO variable. Use 'default-value' and 'setq-default' to access and
679 change FOO, respectively. The exhaustive list of removed variables is:
680 'default-mode-line-format', 'default-header-line-format',
681 'default-line-spacing', 'default-abbrev-mode', 'default-ctl-arrow',
682 'default-truncate-lines', 'default-left-margin', 'default-tab-width',
683 'default-case-fold-search', 'default-left-margin-width',
684 'default-right-margin-width', 'default-left-fringe-width',
685 'default-right-fringe-width', 'default-fringes-outside-margins',
686 'default-scroll-bar-width', 'default-vertical-scroll-bar',
687 'default-indicate-empty-lines', 'default-indicate-buffer-boundaries',
688 'default-fringe-indicator-alist', 'default-fringe-cursor-alist',
689 'default-scroll-up-aggressively', 'default-scroll-down-aggressively',
690 'default-fill-column', 'default-cursor-type',
691 'default-cursor-in-non-selected-windows',
692 'default-buffer-file-coding-system', 'default-major-mode', and
693 'default-enable-multibyte-characters'.
694 *** Many variables obsoleted in 22.1 referring to face symbols
697 ** The variable 'text-quoting-style' no longer affects the treatment
698 of curved quotes in format arguments to functions like 'message' and
699 'format-message'. In particular, when this variable's value is
700 'grave', all quotes in formats are output as-is.
702 ** Functions like 'check-declare-file' and 'check-declare-directory'
703 now generate less chatter and more-compact diagnostics. The auxiliary
704 function 'check-declare-errmsg' has been removed.
707 * Lisp Changes in Emacs 26.1
709 ** New variable 'while-no-input-ignore-events' which allow
710 setting which special events 'while-no-input' should ignore.
711 It is a list of symbols.
713 ** New function 'undo-amalgamate-change-group' to get rid of
714 undo-boundaries between two states.
716 ** New var 'definition-prefixes' is a hash table mapping prefixes to
717 the files where corresponding definitions can be found. This can be
718 used to fetch definitions that are not yet loaded, for example for
721 ** New var 'syntax-ppss-table' to control the syntax-table used in
725 ** 'define-derived-mode' can now specify an :after-hook form, which
726 gets evaluated after the new mode's hook has run. This can be used to
727 incorporate configuration changes made in the mode hook into the
730 ** Autoload files can be generated without timestamps,
731 by setting 'autoload-timestamps' to nil.
732 FIXME As an experiment, nil is the current default.
733 If no insurmountable problems before next release, it can stay that way.
736 ** 'gnutls-boot' now takes a parameter ':complete-negotiation' that
737 says that negotiation should complete even on non-blocking sockets.
740 ** New functions 'window-pixel-width-before-size-change' and
741 'window-pixel-height-before-size-change' support detecting which
742 window changed size when 'window-size-change-functions' are run.
745 ** New function 'display-buffer-reuse-mode-window' is an action function
746 suitable for use in 'display-buffer-alist'. For example, to avoid creating
747 a new window when opening man pages when there's already one, use
748 (add-to-list 'display-buffer-alist
749 '("\\`\\*Man .*\\*\\'" .
750 (display-buffer-reuse-mode-window
751 (inhibit-same-window . nil)
755 ** There is now a new variable 'flyspell-sort-corrections-function'
756 that allows changing the way corrections are sorted.
759 ** The new command 'fortune-message' has been added, which displays
760 fortunes in the echo area.
763 ** New function 'func-arity' returns information about the argument list
764 of an arbitrary function. This generalizes 'subr-arity' for functions
765 that are not built-in primitives. We recommend using this new
766 function instead of 'subr-arity'.
769 ** 'parse-partial-sexp' state has a new element. Element 10 is
770 non-nil when the last character scanned might be the first character
771 of a two character construct, i.e., a comment delimiter or escaped
772 character. Its value is the syntax of that last character.
775 ** 'parse-partial-sexp's state, element 9, has now been confirmed as
776 permanent and documented, and may be used by Lisp programs. Its value
777 is a list of currently open parenthesis positions, starting with the
778 outermost parenthesis.
781 ** 'read-color' will now display the color names using the color itself
782 as the background color.
784 ** The function 'redirect-debugging-output' now works on platforms
785 other than GNU/Linux.
788 ** The new function 'string-version-lessp' compares strings by
789 interpreting consecutive runs of numerical characters as numbers, and
790 compares their numerical values. According to this predicate,
791 "foo2.png" is smaller than "foo12.png".
794 ** The new function 'char-from-name' converts a Unicode name string
795 to the corresponding character code.
798 ** New functions 'sxhash-eq' and 'sxhash-eql' return hash codes of a
799 Lisp object suitable for use with 'eq' and 'eql' correspondingly. If
800 two objects are 'eq' ('eql'), then the result of 'sxhash-eq'
801 ('sxhash-eql') on them will be the same.
804 ** Function 'sxhash' has been renamed to 'sxhash-equal' for
805 consistency with the new functions. For compatibility, 'sxhash'
806 remains as an alias to 'sxhash-equal'.
809 ** New function `add-variable-watcher' can be used to call a function
810 when a symbol's value is changed. This is used to implement the new
811 debugger command `debug-on-variable-change'.
814 ** Time conversion functions that accept a time zone rule argument now
815 allow it to be OFFSET or a list (OFFSET ABBR), where the integer
816 OFFSET is a count of seconds east of Universal Time, and the string
817 ABBR is a time zone abbreviation. The affected functions are
818 'current-time-string', 'current-time-zone', 'decode-time',
819 'format-time-string', and 'set-time-zone-rule'.
822 ** 'format-time-string' now formats "%q" to the calendar quarter.
824 ** New built-in function 'mapcan' which avoids unnecessary consing (and garbage
828 ** The new functions 'make-nearby-temp-file' and 'temporary-file-directory'
829 can be used for creation of temporary files of remote or mounted directories.
832 ** The new function 'file-local-name' can be used to specify arguments
836 ** The new functions 'file-name-quote', 'file-name-unquote' and
837 'file-name-quoted-p' can be used to quote / unquote file names with
841 ** The new error 'file-missing', a subcategory of 'file-error', is now
842 signaled instead of 'file-error' if a file operation acts on a file
846 ** The function 'delete-directory' no longer signals an error when
847 operating recursively and when some other process deletes the directory
848 or its files before 'delete-directory' gets to them.
850 ** Changes in Frame- and Window- Handling
853 *** Support for side windows is now official. The display action
854 function 'display-buffer-in-side-window' will display its buffer in a
855 side window. Functions for toggling all side windows on a frame,
856 changing and reversing the layout of side windows and returning the main
857 (major non-side) window of a frame are provided. For details consult
858 the section "Side Windows" in the Elisp manual.
861 *** Support for atomic windows - rectangular compositions of windows
862 treated by 'split-window', 'delete-window' and 'delete-other-windows'
863 like a single live window - is now official. For details consult the
864 section "Atomic Windows" in the Elisp manual.
867 *** New 'display-buffer' alist entry 'window-parameters' allows to
868 assign window parameters to the window used for displaying the buffer.
871 *** New window parameter 'no-delete-other-window' prevents that
872 its window gets deleted by 'delete-other-windows'.
875 *** New command 'window-swap-states' swaps the states of two live
879 * Changes in Emacs 26.1 on Non-Free Operating Systems
881 ** Intercepting hotkeys on Windows 7 and later now works better.
882 The new keyboard hooking code properly grabs system hotkeys such as
883 Win-* and Alt-TAB, in a way that Emacs can get at them before the
884 system. This makes the 'w32-register-hot-key' functionality work
885 again on all versions of MS-Windows starting with Windows 7. On
886 Windows NT and later you can now register any hotkey combination. (On
887 Windows 9X, the previous limitations, spelled out in the Emacs manual,
890 ** 'convert-standard-filename' no longer mirrors slashes on MS-Windows.
891 Previously, on MS-Windows this function converted slash characters in
892 file names into backslashes. It no longer does that. If your Lisp
893 program used 'convert-standard-filename' to prepare file names to be
894 passed to subprocesses (which is not the recommended usage of that
895 function), you will now have to mirror slashes in your application
896 code. One possible way is this:
899 (while (string-match "/" file-name start)
900 (aset file-name (match-beginning 0) ?\\)
901 (setq start (match-end 0))))
903 ** GUI sessions now treat SIGINT like Posix platforms do.
904 The effect of delivering a Ctrl-C (SIGINT) signal to a GUI Emacs on
905 MS-Windows is now the same as on Posix platforms -- Emacs saves the
906 session and exits. In particular, this will happen if you start
907 emacs.exe from the Windows shell, then type Ctrl-C into that shell's
911 ** 'signal-process' supports SIGTRAP on Windows XP and later.
912 The 'kill' emulation on Windows now maps SIGTRAP to a call to the
913 'DebugBreakProcess' API. This causes the receiving process to break
914 execution and return control to the debugger. If no debugger is
915 attached to the receiving process, the call is typically ignored.
916 This is in contrast to the default action on POSIX Systems, where it
917 causes the receiving process to terminate with a core dump if no
918 debugger has been attached to it.
921 ----------------------------------------------------------------------
922 This file is part of GNU Emacs.
924 GNU Emacs is free software: you can redistribute it and/or modify
925 it under the terms of the GNU General Public License as published by
926 the Free Software Foundation, either version 3 of the License, or
927 (at your option) any later version.
929 GNU Emacs is distributed in the hope that it will be useful,
930 but WITHOUT ANY WARRANTY; without even the implied warranty of
931 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
932 GNU General Public License for more details.
934 You should have received a copy of the GNU General Public License
935 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
941 paragraph-separate: "[
\f]*$"