1 GNU Emacs NEWS -- history of user-visible changes.
3 Copyright (C) 2016-2018 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.18, and NEWS.1-17 for changes
13 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 have been done.
20 (This means all the relevant manuals in doc/ AND lisp doc-strings.)
21 --- means doc strings are updated, and 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
28 ** By default libgnutls is now required when building Emacs.
29 Use 'configure --with-gnutls=no' to build even when GnuTLS is missing.
32 ** GnuTLS version 2.12.2 or later is now required, instead of merely
33 version 2.6.6 or later.
36 ** The new option 'configure --with-mailutils' causes Emacs to rely on
37 GNU Mailutils to retrieve email. It is recommended, and is the
38 default if GNU Mailutils is installed. When --with-mailutils is not
39 in effect, the Emacs build procedure by default continues to build and
40 install a limited 'movemail' substitute that retrieves POP3 email only
41 via insecure channels. To avoid this problem, use either
42 --with-mailutils or --without-pop when configuring; --without-pop
43 is the default on platforms other than native MS-Windows.
46 ** The new option 'configure --enable-gcc-warnings=warn-only' causes
47 GCC to issue warnings without stopping the build. This behavior is
48 now the default in developer builds. As before, use
49 '--disable-gcc-warnings' to suppress GCC's warnings, and
50 '--enable-gcc-warnings' to stop the build if GCC issues warnings.
53 ** When GCC warnings are enabled, '--enable-check-lisp-object-type' is
54 now enabled by default when configuring.
57 ** The Emacs server now has socket-launching support. This allows
58 socket based activation, where an external process like systemd can
59 invoke the Emacs server process upon a socket connection event and
60 hand the socket over to Emacs. Emacs uses this socket to service
61 emacsclient commands. This new functionality can be disabled with the
62 configure option '--disable-libsystemd'.
65 ** A systemd user unit file is provided. Use it in the standard way:
66 'systemctl --user enable emacs'.
67 (If your Emacs is installed in a non-standard location, you may
68 need to copy the emacs.service file to eg ~/.config/systemd/user/)
71 ** New configure option '--disable-build-details' attempts to build an
72 Emacs that is more likely to be reproducible; that is, if you build
73 and install Emacs twice, the second Emacs is a copy of the first.
74 Deterministic builds omit the build date from the output of the
75 'emacs-version' and 'erc-cmd-SV' functions, and the leave the
76 following variables nil: 'emacs-build-system', 'emacs-build-time',
77 'erc-emacs-build-time'.
80 ** Emacs can now be built with support for Little CMS.
82 If the lcms2 library is installed, Emacs will enable features built on
83 top of that library. The new configure option '--without-lcms2' can
84 be used to build without lcms2 support even if it is installed. Emacs
85 linked to Little CMS exposes color management functions in Lisp: the
86 color metrics 'lcms-cie-de2000' and 'lcms-cam02-ucs', as well as
87 functions for conversion to and from CIE CAM02 and CAM02-UCS.
90 ** The configure option '--with-gameuser' now defaults to 'no',
91 as this appears to be the most common configuration in practice.
92 When it is 'no', the shared game directory and the auxiliary program
93 update-game-score are no longer needed and are not installed.
96 ** Emacs no longer works on IRIX. We expect that Emacs users are not
97 affected by this, as SGI stopped supporting IRIX in December 2013.
100 * Startup Changes in Emacs 26.1
103 ** New option '--fg-daemon'. This is the same as '--daemon', except
104 it runs in the foreground and does not fork. This is intended for
105 modern init systems such as systemd, which manage many of the traditional
106 aspects of daemon behavior themselves. '--bg-daemon' is now an alias
110 ** New option '--module-assertions'.
111 When given this option, Emacs will perform expensive correctness
112 checks when dealing with dynamic modules. This is intended for module
113 authors that wish to verify that their module conforms to the module
114 requirements. The option makes Emacs abort if a module-related
118 ** Emacs now supports 24-bit colors on capable text terminals.
119 Terminal is automatically initialized to use 24-bit colors if the
120 required capabilities are found in terminfo. See the FAQ node
121 "(efaq) Colors on a TTY" for more information.
124 ** Emacs now obeys the X resource "scrollBar" at startup.
125 The effect is similar to that of "toolBar" resource on the tool bar.
128 * Changes in Emacs 26.1
131 ** Option 'buffer-offer-save' can be set to new value, 'always'. When
132 set to 'always', the command 'save-some-buffers' will always offer
133 this buffer for saving.
135 ** Security vulnerability related to Enriched Text mode is removed.
138 *** Enriched Text mode does not evaluate Lisp in 'display' properties.
139 This feature allows saving 'display' properties as part of text.
140 Emacs 'display' properties support evaluation of arbitrary Lisp forms
141 as part of processing the property for display, so displaying Enriched
142 Text could be vulnerable to executing arbitrary malicious Lisp code
143 included in the text (e.g., sent as part of an email message).
144 Therefore, execution of arbitrary Lisp forms in 'display' properties
145 decoded by Enriched Text mode is now disabled by default. Customize
146 the new option 'enriched-allow-eval-in-display-props' to a non-nil
147 value to allow Lisp evaluation in decoded 'display' properties.
149 This vulnerability was introduced in Emacs 21.1. To work around that
150 in Emacs versions before 25.3, append the following to your ~/.emacs
153 (eval-after-load "enriched"
154 '(defun enriched-decode-display-prop (start end &optional param)
158 ** Functions in 'write-contents-functions' can fully short-circuit the
159 'save-buffer' process. Previously, saving a buffer that was not
160 visiting a file would always prompt for a file name. Now it only does
161 so if 'write-contents-functions' is nil (or all its functions return
165 ** New variable 'executable-prefix-env' for inserting magic signatures.
166 This variable affects the format of the interpreter magic number
167 inserted by 'executable-set-magic'. If non-nil, the magic number now
168 takes the form "#!/usr/bin/env interpreter", otherwise the value
169 determined by 'executable-prefix', which is by default
170 "#!/path/to/interpreter". By default, 'executable-prefix-env' is nil,
171 so the default behavior is not changed.
174 ** The variable 'emacs-version' no longer includes the build number.
175 This is now stored separately in a new variable, 'emacs-build-number'.
178 ** Emacs now provides a limited form of concurrency with Lisp threads.
179 Concurrency in Emacs Lisp is "mostly cooperative", meaning that
180 Emacs will only switch execution between threads at well-defined
181 times: when Emacs waits for input, during blocking operations related
182 to threads (such as mutex locking), or when the current thread
183 explicitly yields. Global variables are shared among all threads, but
184 a 'let' binding is thread-local. Each thread also has its own current
185 buffer and its own match data.
187 See the chapter "(elisp) Threads" in the ELisp manual for full
188 documentation of these facilities.
191 ** The new user variable 'electric-quote-chars' provides a list
192 of curved quotes for 'electric-quote-mode', allowing user to choose
193 the types of quotes to be used.
196 ** The new user option 'electric-quote-context-sensitive' makes
197 'electric-quote-mode' context sensitive. If it is non-nil, you can
198 type an ASCII apostrophe to insert an opening or closing quote,
199 depending on context. Emacs will replace the apostrophe by an opening
200 quote character at the beginning of the buffer, the beginning of a
201 line, after a whitespace character, and after an opening parenthesis;
202 and it will replace the apostrophe by a closing quote character in all
206 ** The new variable 'electric-quote-inhibit-functions' controls when
207 to disable electric quoting based on context. Major modes can add
208 functions to this list; Emacs will temporarily disable
209 'electric-quote-mode' whenever any of the functions returns non-nil.
210 This can be used by major modes that derive from 'text-mode' but allow
211 inline code segments, such as 'markdown-mode'.
214 ** The new user variable 'dired-omit-case-fold' allows the user to
215 customize the case-sensitivity of dired-omit-mode. It defaults to
216 the same sensitivity as that of the filesystem for the corresponding
220 ** Emacs now uses double buffering to reduce flicker when editing and
221 resizing graphical Emacs frames on the X Window System. This support
222 requires the DOUBLE-BUFFER extension, which major X servers have
223 supported for many years. If your system has this extension, but an
224 Emacs built with double buffering misbehaves on some displays you use,
225 you can disable the feature by adding
227 '(inhibit-double-buffering . t)
229 to default-frame-alist. Or inject this parameter into the selected
230 frame by evaluating this form:
232 (modify-frame-parameters nil '((inhibit-double-buffering . t)))
235 ** The customization group 'wp', whose label was "text", is now
236 deprecated. Use the new group 'text', which inherits from 'wp',
240 ** The new function 'call-shell-region' executes a command in an
241 inferior shell with the buffer region as input.
244 ** The new user option 'shell-command-dont-erase-buffer' controls
245 if the output buffer is erased between shell commands; if non-nil,
246 the output buffer is not erased; this variable also controls where
247 to set the point in the output buffer: beginning of the output,
248 end of the buffer or save the point.
249 When 'shell-command-dont-erase-buffer' is nil, the default value,
250 the behavior of 'shell-command', 'shell-command-on-region' and
251 'async-shell-command' is as usual.
254 ** The new user option 'async-shell-command-display-buffer' controls
255 whether the output buffer of an asynchronous command is shown
256 immediately, or only when there is output.
259 ** New user option 'mouse-select-region-move-to-beginning'.
260 This option controls the position of point when double-clicking
261 mouse-1 on the end of a parenthetical grouping or string-delimiter:
262 the default value nil keeps point at the end of the region, setting it
263 to non-nil moves point to the beginning of the region.
266 ** New user option 'mouse-drag-and-drop-region'.
267 This option allows you to drag the entire region of text to another
268 place or another buffer. Its behavior is customizable via the new
269 options 'mouse-drag-and-drop-region-cut-when-buffers-differ',
270 'mouse-drag-and-drop-region-show-tooltip', and
271 'mouse-drag-and-drop-region-show-cursor'.
274 ** The new user option 'confirm-kill-processes' allows the user to
275 skip a confirmation prompt for killing subprocesses when exiting
276 Emacs. When set to t (the default), Emacs will prompt for
277 confirmation before killing subprocesses on exit, which is the same
281 ** 'find-library-name' will now fall back on looking at 'load-history'
282 to try to locate libraries that have been loaded with an explicit path
286 ** Faces in 'minibuffer-prompt-properties' no longer overwrite properties
287 in the text in functions like 'read-from-minibuffer', but instead are
288 added to the end of the face list. This allows users to say things
289 like '(read-from-minibuffer (propertize "Enter something: " 'face 'bold))'.
292 ** The new variable 'extended-command-suggest-shorter' has been added
293 to control whether to suggest shorter 'M-x' commands or not.
296 ** icomplete now respects 'completion-ignored-extensions'.
299 ** Non-breaking hyphens are now displayed with the 'nobreak-hyphen'
300 face instead of the 'escape-glyph' face.
303 ** Approximations to quotes are now displayed with the new 'homoglyph'
304 face instead of the 'escape-glyph' face.
307 ** New face 'header-line-highlight'.
308 This face is the header-line analogue of 'mode-line-highlight'; it
309 should be the preferred mouse-face for mouse-sensitive elements in the
313 ** 'C-x h' ('mark-whole-buffer') will now avoid marking the prompt
317 ** 'fill-paragraph' no longer marks the buffer as changed unless it
318 actually changed something.
321 ** The locale language name 'ca' is now mapped to the language
322 environment 'Catalan', which has been added.
325 ** 'align-regexp' has a separate history for its interactive argument.
326 'align-regexp' no longer shares its history with all other
327 history-less functions that use 'read-string'.
330 ** The networking code has been reworked so that it's more
331 asynchronous than it was (when specifying :nowait t in
332 'make-network-process'). How asynchronous it is varies based on the
333 capabilities of the system, but on a typical GNU/Linux system the DNS
334 resolution, the connection, and (for TLS streams) the TLS negotiation
335 are all done without blocking the main Emacs thread. To get
336 asynchronous TLS, the TLS boot parameters have to be passed in (see
337 the manual for details).
339 Certain process oriented functions (like 'process-datagram-address')
340 will block until socket setup has been performed. The recommended way
341 to deal with asynchronous sockets is to avoid interacting with them
342 until they have changed status to "run". This is most easily done
343 from a process sentinel.
346 ** 'make-network-process' and 'open-network-stream' sometimes allowed
347 :service to be an integer string (e.g., :service "993") and sometimes
348 required an integer (e.g., :service 993). This difference has been
349 eliminated, and integer strings work everywhere.
352 ** It is possible to disable attempted recovery on fatal signals.
353 Two new variables support disabling attempts to recover from stack
354 overflow and to avoid automatic auto-save when Emacs is delivered a
355 fatal signal. 'attempt-stack-overflow-recovery', if set to nil,
356 will disable attempts to recover from C stack overflows; Emacs will
357 then crash as with any other fatal signal.
358 'attempt-orderly-shutdown-on-fatal-signal', if set to nil, will
359 disable attempts to auto-save the session and shut down in an orderly
360 fashion when Emacs receives a fatal signal; instead, Emacs will
361 terminate immediately. Both variables are non-nil by default.
362 These variables are for users who would like to avoid the small
363 probability of data corruption due to techniques Emacs uses to recover
367 ** File local and directory local variables are now initialized each
368 time the major mode is set, not just when the file is first visited.
369 These local variables will thus not vanish on setting a major mode.
372 ** A second dir-local file (.dir-locals-2.el) is now accepted.
373 See the doc string of 'dir-locals-file' for more information.
376 ** Connection-local variables can be used to specify local variables
377 with a value depending on the connected remote server. For details,
378 see the node "(elisp) Connection Local Variables" in the ELisp manual.
381 ** International domain names (IDNA) are now encoded via the new
382 puny.el library, so that one can visit Web sites with non-ASCII URLs.
385 ** The new 'list-timers' command lists all active timers in a buffer,
386 where you can cancel them with the 'c' command.
389 ** 'switch-to-buffer-preserve-window-point' now defaults to t.
390 Applications that call 'switch-to-buffer' and want to show the buffer at
391 the position of its point should use 'pop-to-buffer-same-window' in lieu
392 of 'switch-to-buffer'.
395 ** The new variable 'debugger-stack-frame-as-list' allows displaying
396 all call stack frames in a Lisp backtrace buffer as lists. Both
397 debug.el and edebug.el have been updated to heed to this variable.
400 ** Values in call stack frames are now displayed using 'cl-prin1'.
401 The old behavior of using 'prin1' can be restored by customizing the
402 new option 'debugger-print-function'.
405 ** NUL bytes in text copied to the system clipboard are now replaced with "\0".
408 ** The new variable 'x-ctrl-keysym' has been added to the existing
409 roster of X keysyms. It can be used in combination with another
410 variable of this kind to swap modifiers in Emacs.
413 ** New input methods: 'cyrillic-tuvan', 'polish-prefix', 'uzbek-cyrillic'.
416 ** The 'dutch' input method no longer attempts to support Turkish too.
417 Also, it no longer converts 'IJ' and 'ij' to the compatibility
418 characters U+0132 LATIN CAPITAL LIGATURE IJ and U+0133 LATIN SMALL
422 ** File name quoting by adding the prefix "/:" is now possible for the
423 local part of a remote file name. Thus, if you have a directory named
424 "/~" on the remote host "foo", you can prevent it from being
425 substituted by a home directory by writing it as "/foo:/:/~/file".
428 ** The new variable 'maximum-scroll-margin' allows having effective
429 settings of 'scroll-margin' up to half the window size, instead of
430 always restricting the margin to a quarter of the window.
433 ** Emacs can scroll horizontally using mouse, touchpad, and trackbar.
434 You can enable this by customizing 'mouse-wheel-tilt-scroll'. If you
435 want to reverse the direction of the scroll, customize
436 'mouse-wheel-flip-direction'.
439 ** The default GnuTLS priority string now includes %DUMBFW.
440 This is to avoid bad behavior in some firewalls, which causes the
441 connection to be closed by the remote host.
443 ** Emacsclient changes
446 *** Emacsclient has a new option '-u' / '--suppress-output'.
447 This option suppresses display of return values from the server
451 *** Emacsclient has a new option '-T' / '--tramp'.
452 This helps with using a local Emacs session as the server for a remote
453 emacsclient. With appropriate setup, one can now set the EDITOR
454 environment variable on a remote machine to emacsclient, and
455 use the local Emacs to edit remote files via Tramp. See the node
456 "(emacs) emacsclient Options" in the user manual for the details.
459 *** Emacsclient now accepts command-line options in ALTERNATE_EDITOR
460 and '--alternate-editor'. For example, ALTERNATE_EDITOR="emacs -Q -nw".
461 Arguments may be quoted "like this", so that for example an absolute
462 path containing a space may be specified; quote escaping is not
466 ** New user option 'dig-program-options' and extended functionality
467 for DNS-querying functions 'nslookup-host', 'dns-lookup-host',
468 and 'run-dig'. Each function now accepts an optional name server
469 argument interactively (with a prefix argument) and non-interactively.
472 ** 'describe-key-briefly' now ignores mouse movement events.
475 ** The new variable 'eval-expression-print-maximum-character' prevents
476 large integers from being displayed as characters by 'M-:' and similar
480 ** Two new commands for finding the source code of Emacs Lisp
481 libraries: 'find-library-other-window' and 'find-library-other-frame'.
484 ** The new variable 'display-raw-bytes-as-hex' allows you to change
485 the display of raw bytes from octal to hex.
488 ** You can now provide explicit field numbers in format specifiers.
489 For example, '(format "%2$s %1$s %2$s" "X" "Y")' produces "Y X Y".
492 ** Emacs now supports optional display of line numbers in the buffer.
493 This is similar to what 'linum-mode' provides, but much faster and
494 doesn't usurp the display margin for the line numbers. Customize the
495 buffer-local variable 'display-line-numbers' to activate this optional
496 display. Alternatively, you can use the 'display-line-numbers-mode'
497 minor mode or the global 'global-display-line-numbers-mode'. When
498 using these modes, customize 'display-line-numbers-type' with the same
499 value as you would use with 'display-line-numbers'.
501 Line numbers are not displayed at all in minibuffer windows and in
502 tooltips, as they are not useful there.
504 Lisp programs can disable line-number display for a particular screen
505 line by putting the 'display-line-numbers-disable' text property or
506 overlay property on the first character of that screen line. This is
507 intended for add-on packages that need a finer control of the display.
509 Lisp programs that need to know how much screen estate is used up for
510 line-number display in a window can use the new function
511 'line-number-display-width'.
513 'linum-mode' and all similar packages are henceforth becoming obsolete.
514 Users and developers are encouraged to switch to this new feature
518 ** The new user option 'arabic-shaper-ZWNJ-handling' controls how to
519 handle ZWNJ in Arabic text rendering.
522 * Editing Changes in Emacs 26.1
525 ** New variable 'column-number-indicator-zero-based'.
526 Traditionally, in Column Number mode, the displayed column number
527 counts from zero starting at the left margin of the window. This
528 behavior is now controlled by 'column-number-indicator-zero-based'.
529 If you would prefer for the displayed column number to count from one,
530 you may set this variable to nil. (Behind the scenes, there is now a
531 new mode line construct, '%C', which operates exactly as '%c' does
532 except that it counts from one.)
535 ** New single-line horizontal scrolling mode.
536 The 'auto-hscroll-mode' variable can now have a new special value,
537 'current-line', which causes only the line where the cursor is
538 displayed to be horizontally scrolled when lines are truncated on
539 display and point moves outside the left or right window margin.
542 ** New mode line constructs '%o' and '%q', and user option
543 'mode-line-percent-position'. '%o' displays the "degree of travel" of
544 the window through the buffer. Unlike the default '%p', this
545 percentage approaches 100% as the window approaches the end of the
546 buffer. '%q' displays the percentage offsets of both the start and
547 the end of the window, e.g. "5-17%". The new option
548 'mode-line-percent-position' makes it easier to switch between '%p',
549 '%P', and these new constructs.
552 ** Two new user options 'list-matching-lines-jump-to-current-line' and
553 'list-matching-lines-current-line-face' to show the current line
554 highlighted in *Occur* buffer.
557 ** The 'occur' command can now operate on the region.
560 ** New bindings for 'query-replace-map'.
561 'undo', undo the last replacement; bound to 'u'.
562 'undo-all', undo all replacements; bound to 'U'.
565 ** 'delete-trailing-whitespace' deletes whitespace after form feed.
566 In modes where form feed was treated as a whitespace character,
567 'delete-trailing-whitespace' would keep lines containing it unchanged.
568 It now deletes whitespace after the last form feed thus behaving the
569 same as in modes where the character is not whitespace.
572 ** Emacs no longer prompts about editing a changed file when the file's
573 content is unchanged. Instead of only checking the modification time,
574 Emacs now also checks the file's actual content before prompting the user.
577 ** Various casing improvements.
579 *** 'upcase', 'upcase-region' et al. convert title case characters
580 (such as Dz) into their upper case form (such as DZ).
582 *** 'capitalize', 'upcase-initials' et al. make use of title-case forms
583 of initial characters (correctly producing for example Džungla instead
584 of incorrect DŽungla).
586 *** Characters which turn into multiple ones when cased are correctly handled.
587 For example, fi ligature is converted to FI when upper cased.
589 *** Greek small sigma is correctly handled when at the end of the word.
590 Strings such as ΌΣΟΣ are now correctly converted to Όσος when
591 capitalized instead of incorrect Όσοσ (compare lowercase sigma at the
595 ** Emacs can now auto-save buffers to visited files in a more robust
596 manner via the new mode 'auto-save-visited-mode'. Unlike
597 'auto-save-visited-file-name', this mode uses the normal saving
598 procedure and therefore obeys saving hooks.
599 'auto-save-visited-file-name' is now obsolete.
602 ** New behavior of 'mark-defun'.
603 Prefix argument selects that many (or that many more) defuns.
604 Negative prefix arg flips the direction of selection. Also,
605 'mark-defun' between defuns correctly selects N following defuns (or
606 -N previous for negative arguments). Finally, comments preceding the
607 defun are selected unless they are separated from the defun by a blank
611 ** New command 'replace-buffer-contents'.
612 This command replaces the contents of the accessible portion of the
613 current buffer with the contents of the accessible portion of a
614 different buffer while keeping point, mark, markers, and text
615 properties as intact as possible.
618 ** New commands 'apropos-local-variable' and 'apropos-local-value'.
619 These are buffer-local versions of 'apropos-variable' and
620 'apropos-value', respectively. They show buffer-local variables whose
621 names and values, respectively, match a given pattern.
624 ** More user control of reordering bidirectional text for display.
625 The two new variables, 'bidi-paragraph-start-re' and
626 'bidi-paragraph-separate-re', allow customization of what exactly are
627 paragraphs, for the purposes of bidirectional display.
630 ** New variable 'x-wait-for-event-timeout'.
631 This controls how long Emacs will wait for updates to the graphical
632 state to take effect (making a frame visible, for example).
635 * Changes in Specialized Modes and Packages in Emacs 26.1
638 ** Emacs 26.1 comes with Org v9.1.6.
639 See the file ORG-NEWS for user-visible changes in Org.
642 ** New function 'cl-generic-p'.
647 *** You can answer 'all' in 'dired-do-delete' to delete recursively all
648 remaining directories without more prompts.
651 *** Dired supports wildcards in the directory part of the file names.
654 *** You can now use '`?`' in 'dired-do-shell-command'.
655 It gets replaced by the current file name, like ' ? '.
658 *** A new option 'dired-always-read-filesystem' defaulting to nil.
659 If non-nil, buffers visiting files are reverted before they are
660 searched; for instance, in 'dired-mark-files-containing-regexp' a
661 non-nil value of this option means the file is revisited in a
662 temporary buffer; this temporary buffer is the actual buffer searched:
663 the original buffer visiting the file is not modified.
666 *** Users can now customize mouse clicks in Dired in a more flexible way.
667 The new command 'dired-mouse-find-file' can be bound to a mouse click
668 and used to visit files/directories in Dired in the selected window.
669 The new command 'dired-mouse-find-file-other-frame' similarly visits
670 files/directories in another frame. You can write your own commands
671 that invoke 'dired-mouse-find-file' with non-default optional
672 arguments, to tailor the effects of mouse clicks on file names in
676 *** In wdired, when editing files to contain slash characters,
677 the resulting directories are automatically created. Whether to do
678 this is controlled by the 'wdired-create-parent-directories' variable.
681 *** 'W' is now bound to 'browse-url-of-dired-file', and is useful for
682 viewing HTML files and the like.
685 *** New variable 'dired-clean-confirm-killing-deleted-buffers'
686 controls whether Dired asks to kill buffers visiting deleted files and
687 directories. The default is t, so Dired asks for confirmation, to
688 keep previous behavior.
691 ** html2text is now marked obsolete.
694 ** smerge-refine-regions can refine regions in separate buffers.
697 ** Info menu and index completion uses substring completion by default.
698 This can be customized via the 'info-menu' category in
699 'completion-category-overrides'.
702 ** The ancestor buffer is shown by default in 3-way merges.
703 A new option 'ediff-show-ancestor' and a new toggle
704 'ediff-toggle-show-ancestor'.
707 ** TeX: Add luatex and xetex as alternatives to pdftex
709 ** Electric-Buffer-menu
712 *** Key 'U' is bound to 'Buffer-menu-unmark-all' and key 'M-DEL' is
713 bound to 'Buffer-menu-unmark-all-buffers'.
716 ** hideshow mode got four key bindings that are analogous to outline
717 mode bindings: 'C-c @ C-a', 'C-c @ C-t', 'C-c @ C-d', and 'C-c @ C-e'.
722 *** Two new commands 'bs-unmark-all', bound to 'U', and
723 'bs-unmark-previous', bound to <backspace>.
728 *** Two new commands 'Buffer-menu-unmark-all', bound to 'U' and
729 'Buffer-menu-unmark-all-buffers', bound to 'M-DEL'.
734 *** 'checkdoc-arguments-in-order-flag' now defaults to nil.
739 *** The ~/.newsrc file will now only be saved if the native select
740 method is an NNTP select method.
743 *** A new command for sorting articles by readedness marks has been
744 added: 'C-c C-s C-m C-m'.
747 *** In 'message-citation-line-format' the '%Z' format is now the time
748 zone name instead of the numeric form. The '%z' format continues to
749 be the numeric form. The new behavior is compatible with
750 'format-time-string'.
755 *** New command 'ibuffer-jump'.
758 *** New filter commands 'ibuffer-filter-by-basename',
759 'ibuffer-filter-by-file-extension', 'ibuffer-filter-by-directory',
760 'ibuffer-filter-by-starred-name', 'ibuffer-filter-by-modified'
761 and 'ibuffer-filter-by-visiting-file'; bound respectively
762 to '/b', '/.', '//', '/*', '/i' and '/v'.
765 *** Two new commands 'ibuffer-filter-chosen-by-completion'
766 and 'ibuffer-and-filter', the second bound to '/&'.
769 *** The commands 'ibuffer-pop-filter', 'ibuffer-pop-filter-group',
770 'ibuffer-or-filter' and 'ibuffer-filter-disable' have the alternative
771 bindings '/<up>', '/S-<up>', '/|' and '/DEL', respectively.
774 *** The data format specifying filters has been extended to allow
775 explicit logical 'and', and a more flexible form for logical 'not'.
776 See 'ibuffer-filtering-qualifiers' doc string for full details.
779 *** A new command 'ibuffer-copy-buffername-as-kill'; bound
783 *** New command 'ibuffer-change-marks'; bound to '* c'.
786 *** A new command 'ibuffer-mark-by-locked' to mark
787 all locked buffers; bound to '% L'.
790 *** A new option 'ibuffer-locked-char' to indicate
791 locked buffers; Ibuffer shows a new column displaying
792 'ibuffer-locked-char' for locked buffers.
795 *** A new command 'ibuffer-unmark-all-marks' to unmark
796 all buffers without asking confirmation; bound to
797 'U'; 'ibuffer-do-replace-regexp' bound to 'r'.
800 *** A new command 'ibuffer-mark-by-content-regexp' to mark buffers
801 whose content matches a regexp; bound to '% g'.
804 *** Two new options 'ibuffer-never-search-content-name' and
805 'ibuffer-never-search-content-mode' used by
806 'ibuffer-mark-by-content-regexp'.
811 *** Support for opening links to man pages in Man or WoMan mode.
816 *** New user option 'comint-move-point-for-matching-input' to control
817 where to place point after 'C-c M-r' and 'C-c M-s'.
820 *** New user option 'comint-terminfo-terminal'.
821 This option allows control of the value of the TERM environment
822 variable Emacs puts into the environment of the Comint mode and its
823 derivatives, such as Shell mode and Compilation Shell minor-mode. The
824 default is "dumb", for compatibility with previous behavior.
829 *** Messages from CMake are now recognized.
832 *** The number of errors, warnings, and informational messages is now
833 displayed in the mode line. These are updated as compilation
839 *** Grep commands will now use GNU grep's '--null' option if
840 available, which allows distinguishing the filename from contents if
841 they contain colons. This can be controlled by the new custom option
842 'grep-use-null-filename-separator'.
845 *** The grep/rgrep/lgrep functions will now ask about saving files
846 before running. This is controlled by the 'grep-save-buffers'
852 *** Edebug can be prevented from pausing 1 second after reaching a
853 breakpoint (e.g. with "f" and "o") by customizing the new option
854 'edebug-sit-on-break'.
857 *** New customizable option 'edebug-max-depth'.
858 This allows you to enlarge the maximum recursion depth when
864 *** 'eshell-input-filter's value is now a named function
865 'eshell-input-filter-default', and has a new custom option
866 'eshell-input-filter-initial-space' to ignore adding commands prefixed
867 with blank space to eshell history.
872 *** Backward compatibility support for BBDB versions less than 3
873 (i.e., BBDB 2.x) is deprecated and will likely be removed in the next
874 major release of Emacs. Users of BBDB 2.x should plan to upgrade to
880 *** New 'M-RET' command for opening a link at point in a new eww buffer.
883 *** A new 's' command for switching to another eww buffer via the minibuffer.
886 *** The 'o' command ('shr-save-contents') has moved to 'O' to avoid collision
887 with the 'o' command from 'image-map'.
890 *** A new command 'C' ('eww-toggle-colors') can be used to toggle
891 whether to use the HTML-specified colors or not. The user can also
892 customize the 'shr-use-colors' variable.
895 *** Images that are being loaded are now marked with gray
896 "placeholder" images of the size specified by the HTML. They are then
897 replaced by the real images asynchronously, which will also now
898 respect width/height HTML specs (unless they specify widths/heights
899 bigger than the current window).
902 *** The 'w' command on links is now 'shr-maybe-probe-and-copy-url'.
903 'shr-copy-url' now only copies the url at point; users who wish to
904 avoid accidentally accessing remote links may rebind 'w' and 'u' in
905 'eww-link-keymap' to it.
910 *** The commands 'find-alternate-file-other-window',
911 'dired-other-window', 'dired-other-frame', and
912 'display-buffer-other-window' are now remapped to Ido equivalents if
918 *** Images are automatically scaled before displaying based on the
919 'image-scaling-factor' variable (if Emacs supports scaling the images
923 *** It's now possible to specify aspect-ratio preserving combinations
924 of :width/:max-height and :height/:max-width keywords. In either
925 case, the "max" keywords win. (Previously some combinations would,
926 depending on the aspect ratio of the image, just be ignored and in
927 other instances this would lead to the aspect ratio not being
931 *** Images inserted with 'insert-image' and related functions get a
932 keymap put into the text properties (or overlays) that span the
933 image. This keymap binds keystrokes for manipulating size and
934 rotation, as well as saving the image to a file. These commands are
935 also available in 'image-mode'.
938 *** A new library for creating and manipulating SVG images has been
939 added. See the "(elisp) SVG Images" section in the ELisp reference
943 *** New setf-able function to access and set image parameters is
944 provided: 'image-property'.
947 *** New commands 'image-scroll-left' and 'image-scroll-right'
948 for 'image-mode' that complement 'image-scroll-up' and
949 'image-scroll-down': they have the same prefix arg behavior and stop
955 *** Now provides a minor mode 'image-dired-minor-mode' which replaces
956 the function 'image-dired-setup-dired-keybindings'.
959 *** Thumbnail generation is now asynchronous.
960 The number of concurrent processes is limited by the variable
961 'image-dired-queue-active-limit'.
964 *** 'image-dired-thumbnail-storage' has a new option 'standard-large'
965 for generating 256x256 thumbnails according to the Thumbnail Managing
969 *** Inherits movement keys from 'image-mode' for viewing full images.
970 This includes the usual char, line, and page movement commands.
973 *** All the -options types have been changed to argument lists
974 instead of shell command strings. This change affects
975 'image-dired-cmd-create-thumbnail-options',
976 'image-dired-cmd-create-temp-image-options',
977 'image-dired-cmd-rotate-thumbnail-options',
978 'image-dired-cmd-rotate-original-options',
979 'image-dired-cmd-write-exif-data-options',
980 'image-dired-cmd-read-exif-data-options', and introduces
981 'image-dired-cmd-pngnq-options', 'image-dired-cmd-pngcrush-options',
982 'image-dired-cmd-create-standard-thumbnail-options'.
985 *** Recognizes more tools by default, including pngnq-s9 and OptiPNG.
988 *** 'find-file' and related commands now work on thumbnails and
989 displayed images, providing a default argument of the original file name
990 via an addition to 'file-name-at-point-functions'.
993 ** The default 'Info-default-directory-list' no longer checks some obsolete
994 directory suffixes (gnu, gnu/lib, gnu/lib/emacs, emacs, lib, lib/emacs)
995 when searching for info directories.
998 ** The commands that add ChangeLog entries now prefer a VCS root directory
999 for the ChangeLog file, if none already exists. Customize
1000 'change-log-directory-files' to nil for the old behavior.
1003 ** Support for non-string values of 'time-stamp-format' has been removed.
1008 *** 'message-use-idna' now defaults to t (because Emacs comes with
1009 built-in IDNA support now).
1012 *** When sending HTML messages with embedded images, and you have
1013 exiftool installed, and you rotate images with EXIF data (i.e.,
1014 JPEGs), the rotational information will be inserted into the outgoing
1015 image in the message. (The original image will not have its
1016 orientation affected.)
1019 *** The 'message-valid-fqdn-regexp' variable has been removed, since
1020 there are now top-level domains added all the time. Message will no
1021 longer warn about sending emails to top-level domains it hasn't heard
1025 *** 'message-beginning-of-line' (bound to 'C-a') understands folded headers.
1026 In 'visual-line-mode' it will look for the true beginning of a header
1027 while in non-'visual-line-mode' it will move the point to the indented
1033 *** The new variable 'package-gnupghome-dir' has been added to control
1034 where the GnuPG home directory (used for signature verification) is
1035 located and whether GnuPG's option '--homedir' is used or not.
1038 *** Deleting a package no longer respects 'delete-by-moving-to-trash'.
1043 *** The new variable 'python-indent-def-block-scale' has been added.
1044 It controls the depth of indentation of arguments inside multi-line
1045 function signatures.
1050 *** The method part of remote file names is mandatory now.
1051 A valid remote file name starts with "/method:host:" or
1052 "/method:user@host:".
1055 *** The new pseudo method "-" is a marker for the default method.
1056 "/-::" is the shortest remote file name then.
1059 *** The command 'tramp-change-syntax' allows you to choose an
1060 alternative remote file name syntax.
1063 *** New connection method "sg", which supports editing files under a
1067 *** New connection method "doas" for OpenBSD hosts.
1070 *** New connection method "gdrive", which allows access to Google
1071 Drive onsite repositories.
1074 *** Gateway methods in Tramp have been removed.
1075 Instead, the Tramp manual documents how to configure ssh and PuTTY
1079 *** Setting the "ENV" environment variable in
1080 'tramp-remote-process-environment' enables reading of shell
1081 initialization files.
1084 *** Tramp is able now to send SIGINT to remote asynchronous processes.
1087 *** Variable 'tramp-completion-mode' is obsoleted.
1090 ** 'auto-revert-use-notify' is set back to t in 'global-auto-revert-mode'.
1095 *** JS mode now sets 'comment-multi-line' to t.
1098 *** New variable 'js-indent-align-list-continuation', when set to nil,
1099 will not align continuations of bracketed lists, but will indent them
1100 by the fixed width 'js-indent-level'.
1105 *** Support for completing attribute values, at-rules, bang-rules,
1106 HTML tags, classes and IDs using the 'completion-at-point' command.
1107 Completion candidates for HTML classes and IDs are retrieved from open
1111 *** CSS mode now binds 'C-h S' to a function that will show
1112 information about a CSS construct (an at-rule, property, pseudo-class,
1113 pseudo-element, with the default being guessed from context). By
1114 default the information is looked up on the Mozilla Developer Network,
1115 but this can be customized using 'css-lookup-url-format'.
1118 *** CSS colors are fontified using the color they represent as the
1119 background. For instance, #ff0000 would be fontified with a red
1123 ** Emacs now supports character name escape sequences in character and
1124 string literals. The syntax variants '\N{character name}' and
1125 '\N{U+code}' are supported.
1128 ** Prog mode has some support for multi-mode indentation.
1129 This allows better indentation support in modes that support multiple
1130 programming languages in the same buffer, like literate programming
1131 environments or ANTLR programs with embedded Python code.
1133 A major mode can provide indentation context for a sub-mode. To
1134 support this, modes should use 'prog-first-column' instead of a
1135 literal zero and avoid calling 'widen' in their indentation functions.
1136 See the node "(elisp) Mode-Specific Indent" in the ELisp manual for
1142 *** New variable 'erc-default-port-tls' used to connect to TLS IRC
1148 *** The new function 'url-cookie-delete-cookie' can be used to
1149 programmatically delete all cookies, or cookies from a specific
1153 *** 'url-retrieve-synchronously' now takes an optional timeout parameter.
1156 *** The URL package now supports HTTPS over proxies supporting CONNECT.
1159 *** 'url-user-agent' now defaults to 'default', and the User-Agent
1160 string is computed dynamically based on 'url-privacy-level'.
1162 ** VC and related modes
1165 *** 'vc-dir-mode' now binds 'vc-log-outgoing' to 'O'; and has various
1166 branch-related commands on a keymap bound to 'B'.
1169 *** 'vc-region-history' is now bound to 'C-x v h', replacing the older
1170 'vc-insert-headers' binding.
1172 *** New user option 'vc-git-print-log-follow' to follow renames in Git logs
1178 *** Opening a .h file will turn C or C++ mode depending on language used.
1179 This is done with the help of the 'c-or-c++-mode' function, which
1180 analyzes buffer contents to infer whether it's a C or C++ source file.
1183 ** New option 'cpp-message-min-time-interval' to allow user control
1184 of progress messages in cpp.el.
1187 ** New DNS mode command 'dns-mode-ipv6-to-nibbles' to convert IPv6 addresses
1188 to a format suitable for reverse lookup zone files.
1193 *** Enchant is now supported as a spell-checker.
1195 Enchant is a meta-spell-checker that uses providers such as Hunspell
1196 to do the actual checking. With it, users can use spell-checkers not
1197 directly supported by Emacs, such as Voikko, Hspell and AppleSpell,
1198 more easily share personal word-lists with other programs, and
1199 configure different spelling-checkers for different languages.
1200 (Version 2.1.0 or later of Enchant is required.)
1205 *** Flymake has been completely redesigned
1207 Flymake now annotates arbitrary buffer regions, not just lines. It
1208 supports arbitrary diagnostic types, not just errors and warnings (see
1209 variable 'flymake-diagnostic-types-alist').
1211 It also supports multiple simultaneous backends, meaning that you can
1212 check your buffer from different perspectives (see variable
1213 'flymake-diagnostic-functions'). Backends for Emacs Lisp mode are
1216 The old Flymake behavior is preserved in the so-called "legacy
1217 backend", which has been updated to benefit from the new UI features.
1222 *** 'term-char-mode' now makes its buffer read-only.
1224 The buffer is made read-only to prevent changes from being made by
1225 anything other than the process filter; and movements of point away
1226 from the process mark are counter-acted so that the cursor is in the
1227 correct position after each command. This is needed to avoid states
1228 which are inconsistent with the state of the terminal understood by
1229 the inferior process.
1231 New user options 'term-char-mode-buffer-read-only' and
1232 'term-char-mode-point-at-process-mark' control these behaviors, and
1233 are non-nil by default. Customize these options to nil if you want
1234 the previous behavior.
1239 *** When an *xref* buffer is needed, 'TAB' quits and jumps to an xref.
1241 A new command 'xref-quit-and-goto-xref', bound to 'TAB' in *xref*
1242 buffers, quits the window before jumping to the destination. In many
1243 situations, the intended window configuration is restored, just as if
1244 the *xref* buffer hadn't been necessary in the first place.
1247 * New Modes and Packages in Emacs 26.1
1250 ** New Elisp data-structure library 'radix-tree'.
1253 ** New library 'xdg' with utilities for some XDG standards and specs.
1258 *** A new submode of 'html-mode', 'mhtml-mode', is now the default
1259 mode for *.html files. This mode handles indentation,
1260 fontification, and commenting for embedded JavaScript and CSS.
1263 ** New mode 'conf-toml-mode' is a sub-mode of 'conf-mode', specialized
1264 for editing TOML files.
1267 ** New mode 'conf-desktop-mode' is a sub-mode of 'conf-unix-mode',
1268 specialized for editing freedesktop.org desktop entries.
1271 ** New minor mode 'pixel-scroll-mode' provides smooth pixel-level scrolling.
1274 ** New major mode 'less-css-mode' (a minor variant of 'css-mode') for
1278 ** New package 'auth-source-pass' integrates 'auth-source' with the
1279 password manager password-store (http://passwordstore.org).
1282 * Incompatible Lisp Changes in Emacs 26.1
1285 ** 'password-data' is now a hash-table so that 'password-read' can use
1286 any object for the 'key' argument.
1289 ** Command 'dired-mark-extension' now automatically prepends a '.' to the
1290 extension when not present. The new command 'dired-mark-suffix' behaves
1291 similarly but it doesn't prepend a '.'.
1294 ** Certain cond/pcase/cl-case forms are now compiled using a faster jump
1295 table implementation. This uses a new bytecode op 'switch', which
1296 isn't compatible with previous Emacs versions. This functionality can
1297 be disabled by setting 'byte-compile-cond-use-jump-table' to nil.
1300 ** If 'comment-auto-fill-only-comments' is non-nil, 'auto-fill-function'
1301 is now called only if either no comment syntax is defined for the
1302 current buffer or the self-insertion takes place within a comment.
1305 ** The alist 'ucs-names' is now a hash table.
1308 ** 'if-let' and 'when-let' are subsumed by 'if-let*' and 'when-let*'.
1309 The incumbent 'if-let' and 'when-let' are now marked obsolete.
1310 'if-let*' and 'when-let*' do not accept the single tuple special case.
1311 New macro 'and-let*' is an implementation of the Scheme SRFI-2 syntax
1312 of the same name. 'if-let*' and 'when-let*' now accept the same
1313 binding syntax as 'and-let*'.
1316 ** 'C-up', 'C-down', 'C-left' and 'C-right' are now defined in term
1317 mode to send the same escape sequences that xterm does. This makes
1318 things like 'forward-word' in readline work.
1321 ** Customizable variable 'query-replace-from-to-separator'
1322 now doesn't propertize the string value of the separator.
1323 Instead, text properties are added by 'query-replace-read-from'.
1324 Additionally, the new nil value restores pre-24.5 behavior
1325 of not providing replacement pairs via the history.
1328 ** Some obsolete functions, variables, and faces have been removed:
1330 *** 'make-variable-frame-local'. Variables cannot be frame-local any more.
1332 *** From subr.el: 'window-dot', 'set-window-dot', 'read-input',
1333 'show-buffer', 'eval-current-buffer', 'string-to-int'.
1335 *** 'icomplete-prospects-length'.
1337 *** All the default-FOO variables that hold the default value of the
1338 FOO variable. Use 'default-value' and 'setq-default' to access and
1339 change FOO, respectively. The exhaustive list of removed variables is:
1340 'default-mode-line-format', 'default-header-line-format',
1341 'default-line-spacing', 'default-abbrev-mode', 'default-ctl-arrow',
1342 'default-truncate-lines', 'default-left-margin', 'default-tab-width',
1343 'default-case-fold-search', 'default-left-margin-width',
1344 'default-right-margin-width', 'default-left-fringe-width',
1345 'default-right-fringe-width', 'default-fringes-outside-margins',
1346 'default-scroll-bar-width', 'default-vertical-scroll-bar',
1347 'default-indicate-empty-lines', 'default-indicate-buffer-boundaries',
1348 'default-fringe-indicator-alist', 'default-fringe-cursor-alist',
1349 'default-scroll-up-aggressively', 'default-scroll-down-aggressively',
1350 'default-fill-column', 'default-cursor-type',
1351 'default-cursor-in-non-selected-windows',
1352 'default-buffer-file-coding-system', 'default-major-mode', and
1353 'default-enable-multibyte-characters'.
1355 *** Many variables obsoleted in 22.1 referring to face symbols.
1358 ** The variable 'text-quoting-style' is now a customizable option. It
1359 controls whether to and how to translate ASCII quotes in messages and
1360 help output. Its possible values and their semantics remain unchanged
1361 from Emacs 25. In particular, when this variable's value is 'grave',
1362 all quotes in formats are output as-is.
1365 ** Functions like 'check-declare-file' and 'check-declare-directory'
1366 now generate less chatter and more-compact diagnostics. The auxiliary
1367 function 'check-declare-errmsg' has been removed.
1370 ** The regular expression character class '[:blank:]' now matches
1371 Unicode horizontal whitespace as defined in the Unicode Technical
1372 Standard #18. If you only want to match space and tab, use '[ \t]'
1376 ** 'min' and 'max' no longer round their results.
1377 Formerly, they returned a floating-point value if any argument was
1378 floating-point, which was sometimes numerically incorrect. For
1379 example, on a 64-bit host (max 1e16 10000000000000001) now returns its
1380 second argument instead of its first.
1383 ** The variable 'old-style-backquotes' has been made internal and
1384 renamed to 'lread--old-style-backquotes'. No user code should use
1388 ** 'default-file-name-coding-system' now defaults to a coding system
1389 that does not process CRLF. For example, it defaults to 'utf-8-unix'
1390 instead of to 'utf-8'. Before this change, Emacs would sometimes
1391 mishandle file names containing these control characters.
1394 ** 'file-attributes', 'file-symlink-p' and 'make-symbolic-link' no
1395 longer quietly mutate the target of a local symbolic link, so that
1396 Emacs can access and copy them reliably regardless of their contents.
1397 The following changes are involved.
1400 *** 'file-attributes' and 'file-symlink-p' no longer prepend "/:" to
1401 symbolic links whose targets begin with "/" and contain ":". For
1402 example, if a symbolic link "x" has a target "/y:z:", '(file-symlink-p
1403 "x")' now returns "/y:z:" rather than "/:/y:z:".
1406 *** 'make-symbolic-link' no longer looks for file name handlers of
1407 target when creating a symbolic link. For example,
1408 '(make-symbolic-link "/y:z:" "x")' now creates a symbolic link to
1409 "/y:z:" instead of failing.
1412 *** 'make-symbolic-link' removes the remote part of a link target if
1413 target and newname have the same remote part. For example,
1414 '(make-symbolic-link "/x:y:a" "/x:y:b")' creates a link with the
1415 literal string "a"; and '(make-symbolic-link "/x:y:a" "/x:z:b")'
1416 creates a link with the literal string "/x:y:a" instead of failing.
1419 *** 'make-symbolic-link' now expands a link target with leading "~"
1420 only when the optional third arg is an integer, as when invoked
1421 interactively. For example, '(make-symbolic-link "~y" "x")' now
1422 creates a link with target the literal string "~y"; to get the old
1423 behavior, use '(make-symbolic-link (expand-file-name "~y") "x")'. To
1424 avoid this expansion in interactive use, you can now prefix the link
1425 target with "/:". For example, '(make-symbolic-link "/:~y" "x" 1)'
1426 now creates a link to literal "~y".
1429 ** 'file-truename' returns a quoted file name if the target of a
1430 symbolic link has remote file name syntax.
1433 ** Module functions are now implemented slightly differently; in
1434 particular, the function 'internal--module-call' has been removed.
1435 Code that depends on undocumented internals of the module system might
1439 ** The argument LOCKNAME of 'write-region' is propagated to file name
1443 ** When built against recent versions of GTK+, Emacs always uses
1444 gtk_window_move for moving frames and ignores the value of the
1445 variable 'x-gtk-use-window-move'. The variable is now obsolete.
1448 ** Several functions that create or rename files now treat their
1449 destination argument specially only when it is a directory name, i.e.,
1450 when it ends in '/' on GNU and other POSIX-like systems. When the
1451 destination argument D of one of these functions is an existing
1452 directory and the intent is to act on an entry in that directory, D
1453 should now be a directory name. For example, (rename-file "e" "f/")
1454 renames to 'f/e'. Although this formerly happened sometimes even when
1455 D was not a directory name, as in (rename-file "e" "f") where 'f'
1456 happened to be a directory, the old behavior often contradicted the
1457 documentation and had inherent races that led to security holes. A
1458 call like (rename-file C D) that used the old, undocumented behavior
1459 can be written as (rename-file C (file-name-as-directory D)), a
1460 formulation portable to both older and newer versions of Emacs.
1461 Affected functions include 'add-name-to-file', 'copy-directory',
1462 'copy-file', 'format-write-file', 'gnus-copy-file',
1463 'make-symbolic-link', 'rename-file', 'thumbs-rename-images', and
1467 ** The list returned by 'overlays-at' is now in decreasing priority order.
1468 The documentation of this function always said the order should be
1469 that of decreasing priority, if the 2nd argument of the function is
1470 non-nil, but the code returned the list in the increasing order of
1471 priority instead. Now the code does what the documentation says it
1475 ** 'format' now avoids allocating a new string in more cases.
1476 'format' was previously documented to return a newly-allocated string,
1477 but this documentation was not correct, as (eq x (format x)) returned
1478 t when x was the empty string. 'format' is no longer documented to
1479 return a newly-allocated string, and the implementation now takes
1480 advantage of the doc change to avoid making copies of strings in
1481 common cases like (format "foo") and (format "%s" "foo").
1484 ** The function 'eldoc-message' now accepts a single argument.
1485 Programs that called it with multiple arguments before should pass
1486 them through 'format' first. Even that is discouraged: for ElDoc
1487 support, you should set 'eldoc-documentation-function' instead of
1488 calling 'eldoc-message' directly.
1491 ** Using '&rest' or '&optional' incorrectly is now an error.
1492 For example giving '&optional' without a following variable, or
1493 passing '&optional' multiple times:
1495 (defun foo (&optional &rest x))
1496 (defun bar (&optional &optional x))
1498 Previously, Emacs would just ignore the extra keyword, or give
1499 incorrect results in certain cases.
1502 ** The pinentry.el library has been removed.
1503 That package (and the corresponding change in GnuPG and pinentry)
1504 was intended to provide a way to input passphrase through Emacs with
1505 GnuPG 2.0. However, the change to support that was only implemented
1506 in GnuPG >= 2.1 and didn't get backported to GnuPG 2.0. And with
1507 GnuPG 2.1 and later, pinentry.el is not needed at all. So the
1508 library was useless, and we removed it. GnuPG 2.0 is no longer
1509 supported by the upstream project.
1511 To adapt to the change, you may need to set 'epa-pinentry-mode' to the
1514 Note that previously, it was said that passphrase input through
1515 minibuffer would be much less secure than other graphical pinentry
1516 programs. However, these days the difference is insignificant: the
1517 'read-password' function sufficiently protects input from leakage to
1518 message logs. Emacs still doesn't use secure memory to protect
1519 passphrases, but it was also removed from other pinentry programs as
1520 the attack is unrealistic on modern computer systems which don't
1521 utilize swap memory usually.
1524 * Lisp Changes in Emacs 26.1
1527 ** The function 'assoc' now takes an optional third argument TESTFN.
1528 This argument, when non-nil, is used for comparison instead of
1532 ** New optional argument TESTFN in 'alist-get', 'map-elt' and 'map-put'.
1533 If non-nil, the argument specifies a function to use for comparison,
1534 instead of, respectively, 'assq' and 'eql'.
1537 ** New function 'seq-set-equal-p' to check if SEQUENCE1 and SEQUENCE2
1538 contain the same elements, regardless of the order.
1541 ** The new function 'mapbacktrace' applies a function to all frames of
1542 the current stack trace.
1545 ** The new function 'file-name-case-insensitive-p' tests whether a
1546 given file is on a case-insensitive filesystem.
1549 ** Several accessors for the value returned by 'file-attributes'
1550 have been added. They are: 'file-attribute-type',
1551 'file-attribute-link-number', 'file-attribute-user-id',
1552 'file-attribute-group-id', 'file-attribute-access-time',
1553 'file-attribute-modification-time',
1554 'file-attribute-status-change-time', 'file-attribute-size',
1555 'file-attribute-modes', 'file-attribute-inode-number',
1556 'file-attribute-device-number' and 'file-attribute-collect'.
1559 ** The new function 'buffer-hash' computes a fast, non-consing hash of
1560 a buffer's contents.
1563 ** 'interrupt-process' now consults the list 'interrupt-process-functions',
1564 to determine which function has to be called in order to deliver the
1565 SIGINT signal. This allows Tramp to send the SIGINT signal to remote
1566 asynchronous processes. The hitherto existing implementation has been
1567 moved to 'internal-default-interrupt-process'.
1570 ** The new function 'read-multiple-choice' prompts for multiple-choice
1571 questions, with a handy way to display help texts.
1574 ** 'comment-indent-function' values may now return a cons to specify a
1575 range of indentation.
1578 ** New optional argument TEXT in 'make-temp-file'.
1581 ** New function 'define-symbol-prop'.
1584 ** New function 'secure-hash-algorithms' to list the algorithms that
1585 'secure-hash' supports.
1586 See the node "(elisp) Checksum/Hash" in the ELisp manual for details.
1589 ** Emacs now exposes the GnuTLS cryptographic API with the functions
1590 'gnutls-macs' and 'gnutls-hash-mac'; 'gnutls-digests' and
1591 'gnutls-hash-digest'; 'gnutls-ciphers' and 'gnutls-symmetric-encrypt'
1592 and 'gnutls-symmetric-decrypt'.
1593 See the node "(elisp) GnuTLS Cryptography" in the ELisp manual for details.
1596 ** The function 'gnutls-available-p' now returns a list of capabilities
1597 supported by the GnuTLS library used by Emacs.
1600 ** Emacs now supports records for user-defined types, via the new
1601 functions 'make-record', 'record', and 'recordp'. Records are now
1602 used internally to represent cl-defstruct and defclass instances, for
1605 If your program defines new record types, you should use
1606 package-naming conventions for naming those types. This is so any
1607 potential conflicts with other types are avoided.
1610 ** 'save-some-buffers' now uses 'save-some-buffers-default-predicate'
1611 to decide which buffers to ask about, if the PRED argument is nil.
1612 The default value of 'save-some-buffers-default-predicate' is nil,
1613 which means ask about all file-visiting buffers.
1616 ** string-(to|as|make)-(uni|multi)byte are now declared obsolete.
1619 ** New variable 'while-no-input-ignore-events' which allow
1620 setting which special events 'while-no-input' should ignore.
1621 It is a list of symbols.
1624 ** New function 'undo-amalgamate-change-group' to get rid of
1625 undo-boundaries between two states.
1628 ** New var 'definition-prefixes' is a hash table mapping prefixes to
1629 the files where corresponding definitions can be found. This can be
1630 used to fetch definitions that are not yet loaded, for example for
1634 ** New var 'syntax-ppss-table' to control the syntax-table used in
1638 ** 'define-derived-mode' can now specify an :after-hook form, which
1639 gets evaluated after the new mode's hook has run. This can be used to
1640 incorporate configuration changes made in the mode hook into the
1644 ** Autoload files can be generated without timestamps,
1645 by setting 'autoload-timestamps' to nil.
1646 FIXME As an experiment, nil is the current default.
1647 If no insurmountable problems before next release, it can stay that way.
1650 ** 'gnutls-boot' now takes a parameter ':complete-negotiation' that
1651 says that negotiation should complete even on non-blocking sockets.
1654 ** There is now a new variable 'flyspell-sort-corrections-function'
1655 that allows changing the way corrections are sorted.
1658 ** The new command 'fortune-message' has been added, which displays
1659 fortunes in the echo area.
1662 ** New function 'func-arity' returns information about the argument list
1663 of an arbitrary function. This generalizes 'subr-arity' for functions
1664 that are not built-in primitives. We recommend using this new
1665 function instead of 'subr-arity'.
1668 ** New function 'region-bounds' can be used in the interactive spec
1669 to provide region boundaries (for rectangular regions more than one)
1670 to an interactively callable function as a single argument instead of
1671 two separate arguments 'region-beginning' and 'region-end'.
1674 ** 'parse-partial-sexp' state has a new element. Element 10 is
1675 non-nil when the last character scanned might be the first character
1676 of a two character construct, i.e., a comment delimiter or escaped
1677 character. Its value is the syntax of that last character.
1680 ** 'parse-partial-sexp's state, element 9, has now been confirmed as
1681 permanent and documented, and may be used by Lisp programs. Its value
1682 is a list of currently open parenthesis positions, starting with the
1683 outermost parenthesis.
1686 ** 'read-color' will now display the color names using the color itself
1687 as the background color.
1690 ** The function 'redirect-debugging-output' now works on platforms
1691 other than GNU/Linux.
1694 ** The new function 'string-version-lessp' compares strings by
1695 interpreting consecutive runs of numerical characters as numbers, and
1696 compares their numerical values. According to this predicate,
1697 "foo2.png" is smaller than "foo12.png".
1700 ** Numeric comparisons and 'logb' no longer return incorrect answers
1701 due to internal rounding errors. For example, '(< most-positive-fixnum
1702 (+ 1.0 most-positive-fixnum))' now correctly returns t on 64-bit hosts.
1705 ** The functions 'ffloor', 'fceiling', 'ftruncate' and 'fround' now
1706 accept only floating-point arguments, as per their documentation.
1707 Formerly, they quietly accepted integer arguments and sometimes
1708 returned nonsensical answers, e.g., '(< N (ffloor N))' could return t.
1711 ** On hosts like GNU/Linux x86-64 where a 'long double' fraction
1712 contains at least EMACS_INT_WIDTH - 3 bits, 'format' no longer returns
1713 incorrect answers due to internal rounding errors when formatting
1714 Emacs integers with '%e', '%f', or '%g' conversions. For example, on
1715 these hosts '(eql N (string-to-number (format "%.0f" N)))' now returns
1716 t for all Emacs integers N.
1719 ** Calls that accept floating-point integers (for use on hosts with
1720 limited integer range) now signal an error if arguments are not
1721 integral. For example '(decode-char 'ascii 0.5)' now signals an
1725 ** Functions 'string-trim-left', 'string-trim-right' and 'string-trim'
1726 now accept optional arguments which specify the regexp of a substring
1730 ** The new function 'char-from-name' converts a Unicode name string
1731 to the corresponding character code.
1734 ** New functions 'sxhash-eq' and 'sxhash-eql' return hash codes of a
1735 Lisp object suitable for use with 'eq' and 'eql' correspondingly. If
1736 two objects are 'eq' ('eql'), then the result of 'sxhash-eq'
1737 ('sxhash-eql') on them will be the same.
1740 ** Function 'sxhash' has been renamed to 'sxhash-equal' for
1741 consistency with the new functions. For compatibility, 'sxhash'
1742 remains as an alias to 'sxhash-equal'.
1745 ** 'make-hash-table' now defaults to a rehash threshold of 0.8125
1746 instead of 0.8, to avoid rounding glitches.
1749 ** New function 'add-variable-watcher' can be used to call a function
1750 when a symbol's value is changed. This is used to implement the new
1751 debugger command 'debug-on-variable-change'.
1754 ** New variable 'print-escape-control-characters' causes 'prin1' and
1755 'print' to output control characters as backslash sequences.
1758 ** Time conversion functions that accept a time zone rule argument now
1759 allow it to be OFFSET or a list (OFFSET ABBR), where the integer
1760 OFFSET is a count of seconds east of Universal Time, and the string
1761 ABBR is a time zone abbreviation. The affected functions are
1762 'current-time-string', 'current-time-zone', 'decode-time',
1763 'format-time-string', and 'set-time-zone-rule'.
1766 ** 'format-time-string' now formats '%q' to the calendar quarter.
1769 ** New built-in function 'mapcan'.
1770 It avoids unnecessary consing (and garbage collection).
1773 ** 'car' and 'cdr' compositions 'cXXXr' and 'cXXXXr' are now part of Elisp.
1776 ** 'gensym' is now part of Elisp.
1779 ** Low-level list functions like 'length' and 'member' now do a better
1780 job of signaling list cycles instead of looping indefinitely.
1783 ** The new functions 'make-nearby-temp-file' and 'temporary-file-directory'
1784 can be used for creation of temporary files on remote or mounted directories.
1787 ** On GNU platforms when operating on a local file, 'file-attributes'
1788 no longer suffers from a race when called while another process is
1789 altering the filesystem. On non-GNU platforms 'file-attributes'
1790 attempts to detect the race, and returns nil if it does so.
1793 ** The new function 'file-local-name' can be used to specify arguments
1794 of remote processes.
1797 ** The new functions 'file-name-quote', 'file-name-unquote' and
1798 'file-name-quoted-p' can be used to quote / unquote file names with
1802 ** The new error 'file-missing', a subcategory of 'file-error', is now
1803 signaled instead of 'file-error' if a file operation acts on a file
1804 that does not exist.
1807 ** The function 'delete-directory' no longer signals an error when
1808 operating recursively and when some other process deletes the directory
1809 or its files before 'delete-directory' gets to them.
1812 ** New error type 'user-search-failed' like 'search-failed' but
1813 avoids debugger like 'user-error'.
1816 ** The function 'line-number-at-pos' now takes a second optional
1817 argument 'absolute'. If this parameter is nil, the default, this
1818 function keeps on returning the line number taking potential narrowing
1819 into account. If this parameter is non-nil, the function ignores
1820 narrowing and returns the absolute line number.
1823 ** The function 'color-distance' now takes a second optional argument
1824 'metric'. When non-nil, it should be a function of two arguments that
1825 accepts two colors and returns a number.
1827 ** Changes in Frame and Window Handling
1830 *** Resizing a frame no longer runs 'window-configuration-change-hook'.
1831 'window-size-change-functions' should be used instead.
1834 *** The new function 'frame-size-changed-p' can tell whether a frame has
1835 been resized since the last time 'window-size-change-functions' has been
1839 *** The function 'frame-geometry' now also returns the width of a
1840 frame's outer border.
1843 *** New frame parameters and changed semantics for older ones:
1846 **** 'z-group' positions a frame above or below all others.
1849 **** 'min-width' and 'min-height' specify the absolute minimum size of a
1853 **** 'parent-frame' makes a frame the child frame of another Emacs
1854 frame. The section "(elisp) Child Frames" in the ELisp manual
1855 describes the intrinsics of that relationship.
1858 **** 'delete-before' triggers deletion of one frame before that of
1862 **** 'mouse-wheel-frame' specifies another frame whose windows shall be
1866 **** 'no-other-frame' has 'next-frame' and 'previous-frame' skip this
1870 **** 'skip-taskbar' removes a frame's icon from the taskbar and has
1871 'Alt-<TAB>' skip this frame.
1874 **** 'no-focus-on-map' avoids that a frame gets input focus when mapped.
1877 **** 'no-accept-focus' means that a frame does not want to get input
1878 focus via the mouse.
1881 **** 'undecorated' removes the window manager decorations from a frame.
1884 **** 'override-redirect' tells the window manager to disregard this
1888 **** 'width' and 'height' now allow the specification of pixel values
1892 **** 'left' and 'top' now allow the specification of ratios.
1895 **** 'keep-ratio' preserves size and position of child frames when their
1896 parent frame is resized.
1899 **** 'no-special-glyphs' suppresses display of truncation and
1900 continuation glyphs in a frame.
1903 **** 'auto-hide-function' and 'minibuffer-exit' handle auto hiding of
1904 frames and exiting from minibuffer individually.
1907 **** 'fit-frame-to-buffer-margins' and 'fit-frame-to-buffer-sizes'
1908 handle fitting a frame to its buffer individually.
1911 **** 'drag-internal-border', 'drag-with-header-line',
1912 'drag-with-mode-line', 'snap-width', 'top-visible' and 'bottom-visible'
1913 allow dragging and resizing frames with the mouse.
1916 **** 'minibuffer' is now set to the default minibuffer window when
1917 initially specified as nil and is not reset to nil when initially
1918 specifying a minibuffer window.
1920 *** The new function 'frame-list-z-order' returns a list of all frames
1921 in Z (stacking) order.
1924 *** The function 'x-focus-frame' optionally tries to not activate its
1928 *** The variable 'focus-follows-mouse' has a third meaningful value
1929 'auto-raise' to indicate that the window manager automatically raises a
1930 frame when the mouse pointer enters it.
1933 *** The new function 'frame-restack' puts a frame above or below
1934 another on the display.
1937 *** The new face 'internal-border' specifies the background of a frame's
1941 *** The NORECORD argument of 'select-window' now has a meaningful value
1942 'mark-for-redisplay' which is like any other non-nil value but marks
1943 WINDOW for redisplay.
1946 *** Support for side windows is now official. The display action
1947 function 'display-buffer-in-side-window' will display its buffer in a
1948 side window. Functions for toggling all side windows on a frame,
1949 changing and reversing the layout of side windows and returning the
1950 main (major non-side) window of a frame are provided. For details
1951 consult the section "(elisp) Side Windows" in the ELisp manual.
1954 *** Support for atomic windows - rectangular compositions of windows
1955 treated by 'split-window', 'delete-window' and 'delete-other-windows'
1956 like a single live window - is now official. For details consult the
1957 section "(elisp) Atomic Windows" in the ELisp manual.
1960 *** New 'display-buffer' alist entry 'window-parameters' allows the
1961 assignment of window parameters to the window used for displaying the
1965 *** New function 'display-buffer-reuse-mode-window' is an action function
1966 suitable for use in 'display-buffer-alist'. For example, to avoid
1967 creating a new window when opening man pages when there's already one,
1970 (add-to-list 'display-buffer-alist
1971 '("\\`\\*Man .*\\*\\'" .
1972 (display-buffer-reuse-mode-window
1973 (inhibit-same-window . nil)
1974 (mode . Man-mode))))
1977 *** New window parameter 'no-delete-other-windows' prevents that
1978 its window gets deleted by 'delete-other-windows'.
1981 *** New window parameters 'mode-line-format' and 'header-line-format'
1982 allow the buffer-local formats for this window to be overridden.
1985 *** New command 'window-swap-states' swaps the states of two live
1989 *** New functions 'window-pixel-width-before-size-change' and
1990 'window-pixel-height-before-size-change' support detecting which
1991 window changed size when 'window-size-change-functions' are run.
1994 *** The new function 'window-lines-pixel-dimensions' returns the pixel
1995 dimensions of a window's text lines.
1998 *** The new function 'window-largest-empty-rectangle' returns the
1999 dimensions of the largest rectangular area not occupying any text in a
2003 *** The semantics of 'mouse-autoselect-window' has changed slightly.
2004 For details see the section "(elisp) Mouse Window Auto-selection" in
2008 *** 'select-frame-by-name' now may return a frame on another display
2009 if it does not find a suitable one on the current display.
2012 ** 'tcl-auto-fill-mode' is now declared obsolete. Its functionality
2013 can be replicated simply by setting 'comment-auto-fill-only-comments'.
2015 ** New pcase pattern 'rx' to match against an rx-style regular expression.
2016 For details, see the doc string of 'rx--pcase-macroexpander'.
2019 ** New functions to set region from secondary selection and vice versa.
2020 The new functions 'secondary-selection-to-region' and
2021 'secondary-selection-from-region' let you set the beginning and the
2022 end of the region from those of the secondary selection and vice
2025 ** New function 'lgstring-remove-glyph' can be used to modify a
2026 gstring returned by the underlying layout engine (e.g. m17n-flt,
2030 * Changes in Emacs 26.1 on Non-Free Operating Systems
2033 ** Intercepting hotkeys on Windows 7 and later now works better.
2034 The new keyboard hooking code properly grabs system hotkeys such as
2035 'Win-*' and 'Alt-TAB', in a way that Emacs can get at them before the
2036 system. This makes the 'w32-register-hot-key' functionality work
2037 again on all versions of MS-Windows starting with Windows 7. On
2038 Windows NT and later you can now register any hotkey combination. (On
2039 Windows 9X, the previous limitations, spelled out in the Emacs manual,
2043 ** 'convert-standard-filename' no longer mirrors slashes on MS-Windows.
2044 Previously, on MS-Windows this function converted slash characters in
2045 file names into backslashes. It no longer does that. If your Lisp
2046 program used 'convert-standard-filename' to prepare file names to be
2047 passed to subprocesses (which is not the recommended usage of that
2048 function), you will now have to mirror slashes in your application
2049 code. One possible way is this:
2052 (while (string-match "/" file-name start)
2053 (aset file-name (match-beginning 0) ?\\)
2054 (setq start (match-end 0))))
2057 ** GUI sessions on MS-Windows now treat SIGINT like Posix platforms do.
2058 The effect of delivering a Ctrl-C (SIGINT) signal to a GUI Emacs on
2059 MS-Windows is now the same as on Posix platforms -- Emacs saves the
2060 session and exits. In particular, this will happen if you start
2061 emacs.exe from the Windows shell, then type Ctrl-C into that shell's
2065 ** 'signal-process' supports SIGTRAP on Windows XP and later.
2066 The 'kill' emulation on Windows now maps SIGTRAP to a call to the
2067 'DebugBreakProcess' API. This causes the receiving process to break
2068 execution and return control to the debugger. If no debugger is
2069 attached to the receiving process, the call is typically ignored.
2070 This is in contrast to the default action on POSIX Systems, where it
2071 causes the receiving process to terminate with a core dump if no
2072 debugger has been attached to it.
2075 ** 'set-mouse-position' and 'set-mouse-absolute-pixel-position' work
2079 ** Emacs can now be run as a GUI application from the command line on
2083 ** 'ns-appearance' and 'ns-transparent-titlebar' change the appearance
2084 of frame decorations on macOS 10.9+.
2087 ** 'ns-use-thin-smoothing' enables thin font smoothing on macOS 10.8+.
2090 ** 'process-attributes' on Darwin systems now returns more information.
2093 ** Mousewheel and trackpad scrolling on macOS 10.7+ now behaves more
2094 like the macOS default. The new variables 'ns-mwheel-line-height',
2095 'ns-use-mwheel-acceleration' and 'ns-use-mwheel-momentum' can be used
2096 to customize the behavior.
2099 ----------------------------------------------------------------------
2100 This file is part of GNU Emacs.
2102 GNU Emacs is free software: you can redistribute it and/or modify
2103 it under the terms of the GNU General Public License as published by
2104 the Free Software Foundation, either version 3 of the License, or
2105 (at your option) any later version.
2107 GNU Emacs is distributed in the hope that it will be useful,
2108 but WITHOUT ANY WARRANTY; without even the implied warranty of
2109 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
2110 GNU General Public License for more details.
2112 You should have received a copy of the GNU General Public License
2113 along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
2119 paragraph-separate: "[
\f]*$"