NEWS 47.2 KB
Newer Older
1
GNU Emacs NEWS -- history of user-visible changes.
2

Paul Eggert's avatar
Paul Eggert committed
3
Copyright (C) 2017-2018 Free Software Foundation, Inc.
4
See the end of the file for license conditions.
Dave Love's avatar
#  
Dave Love committed
5

6
Please send Emacs bug reports to bug-gnu-emacs@gnu.org.
7 8
If possible, use M-x report-emacs-bug.

9
This file is about changes in Emacs version 27.
10

Paul Eggert's avatar
Paul Eggert committed
11
See file HISTORY for a list of GNU Emacs versions and release dates.
12 13
See files NEWS.26, NEWS.25, ..., NEWS.18, and NEWS.1-17 for changes
in older Emacs versions.
14

Paul Eggert's avatar
Paul Eggert committed
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.
17

18 19 20 21 22
Temporary note:
+++ indicates that all necessary documentation updates are complete.
    (This means all relevant manuals in doc/ AND lisp doc-strings.)
--- means no change in the manuals is needed.
When you add a new item, use the appropriate mark if you are sure it applies,
Eli Zaretskii's avatar
Eli Zaretskii committed
23

Michael Albinus's avatar
Michael Albinus committed
24

25
* Installation Changes in Emacs 27.1
Paul Eggert's avatar
Paul Eggert committed
26

27 28 29
** Emacs now uses GMP, the GNU Multiple Precision library.
By default, if 'configure' does not find a suitable libgmp, it
arranges for the included mini-gmp library to be built and used.
30
The new 'configure' option --without-libgmp uses mini-gmp even if a
31
suitable libgmp is available.
Tom Tromey's avatar
Tom Tromey committed
32

33 34 35 36 37 38 39
** The new configure option '--with-json' adds support for JSON using
the Jansson library.  It is on by default; use 'configure
--with-json=no' to build without Jansson support.  The new JSON
functions 'json-serialize', 'json-insert', 'json-parse-string', and
'json-parse-buffer' are typically much faster than their Lisp
counterparts from json.el.

Paul Eggert's avatar
Paul Eggert committed
40 41 42 43 44 45 46
** The etags program now uses the C library's regular expression matcher
when possible, and a compatible regex substitute otherwise.  This will
let developers maintain Emacs's own regex code without having to also
support other programs.  The new configure option '--without-included-regex'
forces etags to use the C library's regex matcher even if the regex
substitute ordinarily would be used to work around compatibility problems.

47 48 49 50 51 52 53
** Emacs has been ported to the -fcheck-pointer-bounds option of GCC.
This causes Emacs to check bounds of some arrays addressed by its
internal pointers, which can be helpful when debugging the Emacs
interpreter or modules that it uses.  If your platform supports it you
can enable it when configuring, e.g., './configure CFLAGS="-g3 -O2
-mmpx -fcheck-pointer-bounds"' on Intel MPX platforms.

54 55 56
** Emacs now normally uses a C pointer type instead of a C integer
type to implement Lisp_Object, which is the fundamental machine word
type internal to the Emacs Lisp interpreter.  This change aims to
57 58 59 60 61
catch typos and support -fcheck-pointer-bounds.  The 'configure'
option --enable-check-lisp-object-type is therefore no longer as
useful and so is no longer enabled by default in developer builds,
to reduce differences between developer and production builds.

62 63
** Ibuffer

64 65 66 67 68
---
*** All mode filters can now accept a list of symbols.
This means you can now easily filter several major modes, as well
as a single mode.

69 70 71 72 73 74 75
** Gnus

+++
*** The nnimap backend now has support for IMAP namespaces.
This feature can be enabled by setting the new 'nnimap-use-namespaces'
server variable to non-nil.

76

77
* Startup Changes in Emacs 27.1
78

79 80 81 82 83 84 85 86 87
+++
** Emacs can now be configured using an early init file.
The file is called 'early-init.el', in 'user-emacs-directory'.  It is
loaded very early in the startup process: before graphical elements
such as the tool bar are initialized, and before the package manager
is initialized.  The primary purpose is to allow customizing how the
package system is initialized given that initialization now happens
before loading the regular init file (see below).

88 89 90 91 92 93 94
We recommend against putting any customizations in this file that
don't need to be set up before initializing installed add-on packages,
because the early init file is read too early into the startup
process, and some important parts of the Emacs session, such as
window-system and other GUI features, are not yet set up, which could
make some customization fail to work.

95
+++
96
** Installed packages are now activated *before* loading the init file.
97 98 99 100
This is part of a change intended to eliminate the behavior of
package.el inserting a call to 'package-initialize' into the init
file, which was previously done when Emacs was started.  As a result
of this change, it is no longer necessary to call 'package-initialize'
101 102 103 104 105 106 107
in your init file.

However, if your init file changes the values of 'package-load-list' or
'package-user-dir', or sets 'package-enable-at-startup' to nil then it won't
work right without some adjustment:
- you can move that code to the early init file (see above), so those settings
  apply before Emacs tries to activate the packages.
108
- you can use the new 'package-quickstart' so activation of packages does not
109
  need to pay attention to 'package-load-list' or 'package-user-dir' any more.
110

111 112 113 114 115 116 117 118
---
** Emacs now notifies systemd when startup finishes or shutdown begins.
Units that are ordered after 'emacs.service' will only be started
after Emacs has finished initialization and is ready for use.
(If your Emacs is installed in a non-standard location and you copied the
emacs.service file to eg ~/.config/systemd/user/, you will need to copy
the new version of the file again.)

119

120
* Changes in Emacs 27.1
121

122 123 124 125 126 127
+++
** emacsclient uses EMACS_SOCKET_NAME if --socket-name is not set.
The behavior is identical to the EMACS_SERVER_FILE, in that the
command line value will override the environment, and the natural
default to TMPDIR, then /tmp, continues to apply.

Tino Calancha's avatar
Tino Calancha committed
128 129 130
+++
** The function 'read-passwd' uses '*' as default character to hide passwords.

131 132 133 134 135 136
---
** The new option 'tooltip-resize-echo-area' avoids truncating tooltip text
on GUI frames when tooltips are displayed in the echo area.  Instead,
it resizes the echo area as needed to accommodate the full tool-tip
text.

137 138 139 140 141 142
---
** Show modeline tooltips only if the corresponding action applies.
Customize the option 'mode-line-default-help-echo' to restore the old
behavior where the tooltip text is also shown when the corresponding
action does not apply.

143 144 145 146 147 148 149 150 151
+++
** New hook 'server-after-make-frame-hook'.
This hook is a convenient place to perform initializations in daemon
mode which require GUI features to be available.  One example is
restoration of the previous session using the desktop.el package: put
the call to 'desktop-read' in this hook, if you want the GUI settings
to be restored, or if desktop.el needs to interact with you during
restoration of the session.

Mark Oteiza's avatar
Mark Oteiza committed
152 153 154
+++
** New function 'logcount' calculates an integer's Hamming weight.

155 156 157 158 159 160 161 162
+++
** New function 'libxml-available-p'.
This function returns non-nil if libxml support is both compiled in
and available at run time.  Lisp programs should use this function to
detect built-in libxml support, instead of testing for that
indirectly, e.g., by checking that functions like
'libxml-parse-html-region' return nil.

163
+++
164
** 'libxml-parse-xml-region' and 'libxml-parse-html' region take
165 166
a parameter that's called DISCARD-COMMENTS, but it really only
discards the top-level comment.  Therefore this parameter is now
167
obsolete, and the new utility function 'xml-remove-comments' can be
168 169 170
used to remove comments before calling the libxml functions to parse
the data.

171 172
+++
** The Network Security Manager now allows more fine-grained control
173
of what checks to run via the 'network-security-protocol-checks'
174 175
variable.

176
+++
177 178 179 180 181 182 183 184 185
** TLS connections have their security tightened by default.
Most of the checks for outdated, believed-to-be-weak TLS algorithms
and ciphers are now switched on by default.  By default, the NSM will
flag connections using these weak algorithms and ask users whether to
allow them.  To get the old behavior back (where certificates are
checked for validity, but no warnings about weak cryptography are
issued), you can either set 'network-security-protocol-checks' to nil,
or adjust the elements in that variable to only happen on the 'high'
security level (assuming you use the 'medium' level).
186

187 188 189 190 191
+++
** New function 'fill-polish-nobreak-p', to be used in 'fill-nobreak-predicate'.
It blocks line breaking after a one-letter word, also in the case when
this word is preceded by a non-space, but non-alphanumeric character.

192 193 194 195 196 197 198
+++
** The limit on repetitions in regexps has been raised to 2^16-1.
It was previously limited to 2^15-1.  For example, the following
regular expression was previously invalid, but is now accepted:

   x\{32768\}

199 200 201
---
** The German prefix and postfix input methods now support Capital sharp S.

202 203 204
---
** New input methods hawaiian-postfix and hawaiian-prefix.

205
+++
206 207 208 209
** New function 'exec-path'.
This function by default returns the value of the corresponding
variable, but can optionally return the equivalent of 'exec-path'
from a remote host.
210 211

+++
212 213
** The function 'executable-find' supports an optional argument REMOTE.
This triggers to search the program on the remote host as indicated by
214 215
'default-directory'.

216 217 218 219 220
+++
** New variable 'auto-save-no-message'.
When set to t, no message will be shown when auto-saving (default
value: nil).

221 222 223 224 225 226
---
** The value of 'make-cursor-line-fully-visible' can now be a function.
In addition to nil or non-nil, the value can now be a predicate
function.  Follow mode uses this to control scrolling of its windows
when the last screen line in a window is not fully visible.

227

228
* Editing Changes in Emacs 27.1
229

230 231 232
+++
** New command 'make-empty-file'.

233 234 235 236 237
---
** New variable 'x-wait-for-event-timeout'.
This controls how long Emacs will wait for updates to the graphical
state to take effect (making a frame visible, for example).

238
+++
239 240 241 242
** New user option 'electric-quote-replace-double'.
This option controls whether '"' is replaced in 'electric-quote-mode',
in addition to other quote characters.  If non-nil, ASCII double-quote
characters that quote text "like this" are replaced by double
243 244
typographic quotes, “like this”, in text modes, and in comments in
non-text modes.
245

246 247 248 249 250 251 252
---
** New user option 'flyspell-case-fold-duplications'.
This option controls whether Flyspell mode considers consecutive words
to be duplicates if they are not in the same case.  If non-nil, the
default, words are considered to be duplicates even if their letters'
case does not match.

253 254 255 256 257
---
** 'write-abbrev-file' now includes special properties.
'write-abbrev-file' now writes special properties like ':case-fixed'
for abbrevs that have them.

Allen Li's avatar
Allen Li committed
258
+++
Allen Li's avatar
Allen Li committed
259 260 261
** 'write-abbrev-file' skips empty tables.
'write-abbrev-file' now skips inserting a 'define-abbrev-table' form for
tables which do not have any non-system abbrevs to save.
Allen Li's avatar
Allen Li committed
262

263
+++
264 265
** The new functions and commands 'text-property-search-forward' and
'text-property-search-backward' have been added.  These provide an
266 267
interface that's more like functions like @code{search-forward}.

Juri Linkov's avatar
Juri Linkov committed
268 269
---
** More commands support noncontiguous rectangular regions, namely
Michael Albinus's avatar
Michael Albinus committed
270
'upcase-dwim', 'downcase-dwim', 'replace-string', 'replace-regexp'.
Juri Linkov's avatar
Juri Linkov committed
271

272 273 274 275 276 277 278
+++
** When asked to visit a large file, Emacs now offers visiting it literally.
Previously, Emacs would only ask for confirmation before visiting
large files.  Now it also offers a third alternative: to visit the
file literally, as in 'find-file-literally', which speeds up
navigation and editing of large files.

279 280 281 282 283 284
---
** add-dir-local-variable now uses dotted pair notation syntax
to write alists of variables to .dir-locals.el.  This is the same
syntax that you can see in the example of a .dir-locals.el file
in (info "(emacs) Directory Variables")

Michael Albinus's avatar
Michael Albinus committed
285

286
* Changes in Specialized Modes and Packages in Emacs 27.1
287

288 289 290 291 292 293
---
** Follow mode
In the current follow group of windows, "ghost" cursors are no longer
displayed in the non-selected follow windows.  To get the old behavior
back, customize follow-hide-ghost-cursors to nil.

294 295 296 297
** Octave mode
The mode is automatically enabled in files that start with the
'function' keyword.

Stefan Monnier's avatar
Stefan Monnier committed
298 299 300 301 302 303 304 305 306 307 308
** project.el
*** New commands project-search and project-query-replace

** Etags
+++
*** 'next-file' is now an obsolete alias of tags-next-file
*** tags-loop-revert-buffers is an obsolete alias of multifile-revert-buffers
*** The tags-loop-continue function along with the tags-loop-operate and
tags-loop-scan variables are now obsolete; use the new multifile-initialize and
multifile-continue functions instead.

309 310 311 312 313 314
---
** bibtex
*** New commands 'bibtex-next-entry' and 'bibtex-previous-entry'.
In bibtex-mode-map, forward-paragraph and backward-paragraph are
remapped to these, respectively.

315 316 317 318 319
+++
** Dired

*** New command 'dired-create-empty-file'.

320 321
** Change Logs and VC

Eli Zaretskii's avatar
Eli Zaretskii committed
322 323 324 325 326 327 328 329
*** Recording ChangeLog entries doesn't require an actual file.
If a ChangeLog file doesn't exist, and if the new variable
'add-log-dont-create-changelog-file' is non-nil (which is the
default), commands such as 'C-x 4 a' will add log entries to a
suitable named temporary buffer.  (An existing ChangeLog file will
still be used if it exists.)  Set the variable to nil to get the
previous behavior of always creating a buffer that visits a ChangeLog
file.
330

331 332 333 334
*** New customizable variable 'vc-git-grep-template'.
This new variable allows customizing the default arguments passed to
git-grep when 'vc-git-grep' is used.

335 336 337 338
*** Command 'vc-git-stash' now respects marks in the '*vc-dir*' buffer.
When some files are marked, only those are stashed.
When no files are marked, all modified files are stashed, as before.

339 340
*** The new hook 'vc-retrieve-tag-hook' runs after retrieving a tag.

341
** diff-mode
342
*** Hunks are now automatically refined by default.
343 344
To disable it, set the new defcustom 'diff-font-lock-refine' to nil.

345
*** File headers can be shortened, mimicking Magit's diff format.
346 347
To enable it, set the new defcustom 'diff-font-lock-prettify to t.

348
** Browse-url
349

350 351 352 353
*** The function 'browse-url-emacs' can now visit a URL in selected window.
It now treats the optional 2nd argument to mean that the URL should be
shown in the currently selected window.

354
** Comint
355

356
+++
357
*** 'send-invisible' is now an obsolete alias for 'comint-send-invisible'.
358 359
Also, 'shell-strip-ctrl-m' is declared obsolete.

360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375
+++
*** 'C-c .' (comint-insert-previous-argument) no longer interprets '&'.
This feature caused problems when '&&' was present in the previous
command.  Since this command emulates 'M-.' in Bash and zsh, neither
of which treats '&' specially, the feature was removed for
compatibility with these shells.

+++
*** 'comint-insert-previous-argument' can now count arguments from the end.
By default, invoking 'C-c .' with a numeric argument N would copy the
Nth argument, counting from the first one.  But if the new option
'comint-insert-previous-argument-from-end' is non-nil, it will copy
the Nth argument counting from the last one.  Thus 'C-c .' can now
better emulate 'M-.' in both Bash and zsh, since the former counts
from the beginning of the arguments, while the latter counts from the
end.
376

377 378 379 380 381 382 383 384 385 386 387 388 389 390 391
** SQL

*** Installation of 'sql-indent' from ELPA is strongly encouraged.
This package support sophisticated rules for properly indenting SQL
statements.  SQL is not like other programming languages like C, Java,
or Python where code is sparse and rules for formatting are fairly
well established. Instead SQL is more like COBOL (from which it came)
and code tends to be very dense and line ending decisions driven by
syntax and line length considerations to make readable code.
Experienced SQL developers may prefer to rely upon existing Emacs
facilities for formatting code but the 'sql-indent' package provides
facilities to aid more casual SQL developers layout queries and
complex expressions.

*** 'sql-use-indent-support' (default t) enables SQL indention support.
392
The 'sql-indent' package from ELPA must be installed to get the
393 394 395 396 397 398 399
indentation support in 'sql-mode' and 'sql-interactive-mode'.

*** 'sql-mode-hook' and 'sql-interactive-mode-hook' changed.
Both hook variables have had 'sql-indent-enable' added to their
default values. If youhave existing customizations to these variables,
you should make sure that the new default entry is included.

400 401 402 403 404
** Term

---
*** 'term-read-noecho' is now obsolete, use 'read-passwd' instead.

405 406 407
** Flymake

+++
408
*** The variable 'flymake-diagnostic-types-alist' is obsolete.
409 410 411
You should instead set properties on known diagnostic symbols, like
':error' and ':warning', as demonstrated in the Flymake manual.

412
*** New customizable variable 'flymake-start-on-save-buffer'.
413 414
Control whether Flymake starts checking the buffer on save.

415
*** Flymake and backend functions may exchange hints about buffer changes.
416 417 418
This enables more efficient backends.  See the docstring of
'flymake-diagnostic-functions' or the Flymake manual for details.

419
** Package
420

421
*** New function 'package-get-version' lets packages query their own version.
422 423
Example use in auctex.el: (defconst auctex-version (package-get-version))

424
*** New 'package-quickstart' feature.
425 426 427 428 429 430 431 432 433
When 'package-quickstart' is non-nil, package.el precomputes a big autoloads
file so that activation of packages can be done much faster, which can speed up
your startup significantly.
It also causes variables like package-user-dir and package-load-list to be
consulted when 'package-quickstart-refresh' is run rather than at startup so
you don't need to set them in your early init file.

*** New function 'package-activate-all'.

434 435 436 437 438 439 440 441 442
** Info

---
*** Info can now follow 'file://' protocol URLs.
The 'file://' URLs in Info documents can now be followed by passing
them to the 'browse-url' function, like the other protocols: ftp,
http, and https.  This allows to have references to local HTML files,
for example.

443 444 445 446 447 448 449
** Xref

+++
*** New command 'xref-find-definitions-at-mouse'.
This command finds definitions of the identifier at the place of a
mouse click event, and is intended to be bound to a mouse event.

450
** Ecomplete
451

452
*** The ecomplete sorting has changed to a decay-based algorithm.
453
This can be controlled by the new 'ecomplete-sort-predicate' variable.
454

455
*** The 'ecompleterc' file is now placed in ~/.emacs.d/ecompleterc by default.
456 457
Of course it will still find it if you have it in ~/.ecompleterc

Paul Eggert's avatar
Paul Eggert committed
458
** Gnus
459 460

+++
461
*** A prefix argument to 'gnus-summary-limit-to-score' will limit reverse.
462 463
Limit to articles with score at below.

Paul Eggert's avatar
Paul Eggert committed
464 465 466
*** The function 'gnus-score-find-favorite-words' has been renamed
from 'gnus-score-find-favourite-words'.

467 468 469 470
---
*** Gmane has been removed as an nnir backend, since Gmane no longer
has a search engine.

471
+++
472 473
*** Splitting mail on common mailing list headers has been added.
See the concept index in the Gnus manual for the 'match-list' entry.
474

475
+++
476
*** nil is no longer an allowed value for 'mm-text-html-renderer'.
477

478
+++
479 480
*** A new Gnus summary mode command, 'S A'
('gnus-summary-attach-article') can be used to attach the current
481 482 483
article(s) to a pre-existing Message buffer, or create a new Message
buffer with the article(s) attached.

484 485 486
** erc

---
487
*** 'erc-button-google-url' has been renamed 'erc-button-search-url'
488 489
and its value has been changed to Duck Duck Go.

490 491 492 493
** EUDC

*** XEmacs support has been removed.

494 495 496
** eww/shr

*** When opening external links in eww/shr (typically with the
497 498
'C-u RET' keystroke on a link), the link will be flashed with the new
'shr-selected-link' face to give the user feedback that the command
499 500
has been executed.

501 502 503 504 505
+++
*** New option 'shr-discard-aria-hidden'.
If set, shr will not render tags with attribute 'aria-hidden="true"'.
This attribute is meant to tell screen readers to ignore a tag.

Paul Eggert's avatar
Paul Eggert committed
506
** Htmlfontify
507

Paul Eggert's avatar
Paul Eggert committed
508 509 510 511 512
*** The functions 'hfy-color', 'hfy-color-vals' and
'hfy-fallback-color-values' and the variables 'hfy-fallback-color-map'
and 'hfy-rgb-txt-color-map' have been renamed from names that used
'colour' instead of 'color'.

513 514 515 516 517 518 519 520
+++
** Enriched mode supports the 'charset' text property.
You can add or modify the 'charset' text properties of text using the
Edit->Text Properties->Special Properties menu, or by invoking the
'facemenu-set-charset' command.  Documents in Enriched mode will be
saved with the charset properties, and those properties will be
restored when the file is visited.

521
** Smtpmail
522

523 524 525
Authentication mechanisms can be added via external packages, by
defining new cl-defmethod of smtpmail-try-auth-method.

526
** Footnote-mode
527

528 529 530 531
*** Support Hebrew-style footnotes
*** Footnote text lines are now aligned.
Can be controlled via the new variable 'footnote-align-to-fn-text'.

532 533 534 535 536 537 538
** CSS mode

---
*** A new command 'css-cycle-color-format' for cycling between color
formats (e.g. "black" => "#000000" => "rgb(0, 0, 0)") has been added,
bound to 'C-c C-f'.

539 540 541
---
*** CSS mode, SCSS mode, and Less CSS mode now have support for Imenu.

542 543 544 545 546 547 548
** SGML mode

---
*** 'sgml-quote' now handles double quotes and apostrophes
when escaping text and in addition all numeric entities when
unescaping text.

549 550 551 552 553 554 555
** Python mode

---
*** Python mode supports three different font lock decoration levels.
The maximum level is used by default; customize
'font-lock-maximum-decoration' to tone down the decoration.

556 557 558 559 560 561 562
** Dired

+++
*** The new user option 'dired-create-destination-dirs' controls whether
'dired-do-copy' and 'dired-rename-file' should create non-existent
directories in the destination.

563 564
** Help

565 566 567 568 569 570 571
---
*** Output format of 'C-h l' (view-lossage) has changed.
For convenience, 'view-lossage' now displays the last keystrokes
and commands in the same format as the edit buffer of
'edit-last-kbd-macro'.  This makes it possible to copy the lines from
the buffer generated by 'view-lossage' to the "*Edit Macro*" buffer
created by 'edit-last-kbd-macro', and to save the macro by 'C-c C-c'.
572

573 574 575 576
---
*** The list of help commands produced by 'C-h C-h' ('help-for-help')
can now be searched via 'C-s'.

577 578 579 580 581
** Ibuffer

---
*** New filter ibuffer-filter-by-process; bound to '/E'.

582 583
** Search and Replace

Juri Linkov's avatar
Juri Linkov committed
584 585
+++
*** New isearch bindings.
586

Juri Linkov's avatar
Juri Linkov committed
587
'C-M-w' in isearch changed from isearch-del-char to the new function
588 589
isearch-yank-symbol-or-char.  isearch-del-char is now bound to
'C-M-d'.
Juri Linkov's avatar
Juri Linkov committed
590

591
+++
592 593 594 595 596 597
*** 'search-exit-option' provides new options 'move' and 'shift-move'
to extend the search string by yanking text that ends at the new
position after moving point in the current buffer.  'shift-move'
extends the search string by motion commands while holding down
the shift key.

Juri Linkov's avatar
Juri Linkov committed
598 599 600 601
---
*** Isearch now remembers the regexp-based search mode for words/symbols
and case-sensitivity together with search strings in the search ring.

602 603 604 605 606
** Debugger

+++
*** The Lisp Debugger is now based on 'backtrace-mode'.
Backtrace mode adds fontification and commands for changing the
607
appearance of backtrace frames.  See the node "Backtraces" in the Elisp
608 609
manual for documentation of the new mode and its commands.

610 611 612 613
** Edebug

+++
*** The runtime behavior of Edebug's instrumentation can be changed
614 615
using the new variables 'edebug-behavior-alist',
'edebug-after-instrumentation-function' and
616
'edebug-new-definition-function'.  Edebug's behavior can be changed
617 618
globally or for individual definitions.

619
+++
620 621 622
*** Edebug's backtrace buffer now uses 'backtrace-mode'.
Backtrace mode adds fontification, links and commands for changing the
appearance of backtrace frames.  See the node "Backtraces" in the Elisp
623 624
manual for documentation of the new mode and its commands.

625 626 627 628 629 630 631 632 633
The binding of 'd' in Edebug's keymap is now 'edebug-pop-to-backtrace'
which replaces 'edebug-backtrace'.  Consequently Edebug's backtrace
windows now behave like those of the Lisp Debugger and of ERT, in that
when they appear they will be the selected window.

The new 'backtrace-goto-source' command, bound to 's', works in
Edebug's backtraces on backtrace frames whose source code has
been instrumented by Edebug.

634 635
** Enhanced xterm support

Mark Oteiza's avatar
Mark Oteiza committed
636 637 638
*** New variable 'xterm-set-window-title' controls whether Emacs sets
the XTerm window title.  This feature is experimental and is disabled
by default.
639

640 641
** grep

642
+++
643 644
*** rgrep, lgrep and zrgrep now hide part of the command line
that contains a list of ignored directories and files.
645 646 647 648
Clicking on the button with ellipsis unhides it.
The abbreviation can be disabled by the new option
'grep-find-abbreviate'.  The new command
'grep-find-toggle-abbreviation' toggles it interactively.
649

Paul Pogonyshev's avatar
Paul Pogonyshev committed
650 651 652 653 654 655
** ERT

+++
*** New variable 'ert-quiet' allows to make ERT output in batch mode
less verbose by removing non-essential information.

656 657 658
+++
*** ERT's backtrace buffer now uses 'backtrace-mode'.
Backtrace mode adds fontification and commands for changing the
659
appearance of backtrace frames.  See the node "Backtraces" in the Elisp
660 661 662 663
manual for documentation of the new mode and its commands.

** Gamegrid

664 665
---
*** Gamegrid now determines its default glyph size based on display
666
dimensions, instead of always using 16 pixels.  As a result, Tetris,
667 668
Snake and Pong are more playable on HiDPI displays.

669 670 671 672 673 674
** Filecache

---
*** Completing filenames in the minibuffer via 'C-TAB' now uses the
styles as configured by the variable 'completion-styles'.

675 676 677 678
** New macros 'thunk-let' and 'thunk-let*'.
These macros are analogue to 'let' and 'let*', but create bindings that
are evaluated lazily.

679 680
** next-error

681
+++
682
*** New customizable variable 'next-error-find-buffer-function'.
683 684 685 686 687 688 689 690 691
The value should be a function that determines how to find the
next buffer to be used by 'next-error' and 'previous-error'.  The
default is to use the last buffer that navigated to the current
error.

+++
*** New command 'next-error-select-buffer'.
It can be used to set any buffer as the next one to be used by
'next-error' and 'previous-error'.
692 693 694

** nxml-mode

Eli Zaretskii's avatar
Eli Zaretskii committed
695 696
---
*** The default value of 'nxml-sexp-element-flag' is now t.
697 698 699
This means that pressing C-M-SPACE now selects the entire tree by
default, and not just the opening element.

700 701 702 703 704 705 706 707 708
** Eshell

---
*** Expansion of history event designators is disabled by default.
To restore the old behavior, use

    (add-hook 'eshell-expand-input-functions
              #'eshell-expand-history-references)

Glenn Morris's avatar
Glenn Morris committed
709 710
---
*** The function 'eshell-uniquify-list' has been renamed from
Paul Eggert's avatar
Paul Eggert committed
711 712
'eshell-uniqify-list'.

713 714 715 716
*** The function eshell/kill is now able to handle signal switches.
Previously eshell/kill would fail if provided a kill signal to send to the
process.  It now accepts signals specified either by name or by its number.

717 718 719 720 721
** Shell

---
*** Program name completion inside remote shells works now as expected.

Paul Eggert's avatar
Paul Eggert committed
722 723 724 725
** Pcomplete
*** The function 'pcomplete-uniquify-list' has been renamed from
'pcomplete-uniqify-list'.

Michael Albinus's avatar
Michael Albinus committed
726 727 728 729 730
** Auth-source

---
*** The Secret Service backend supports the :create key now.

731 732 733
** Tramp

+++
734
*** New connection method "nextcloud", which allows to access OwnCloud
735 736
or NextCloud hosted files and directories.

737 738 739 740
+++
*** Connection methods "obex" and "synce" are removed, because they
are obsoleted in GVFS.

Michael Albinus's avatar
Michael Albinus committed
741 742 743
+++
*** Validated passwords are saved by auth-source backends which support this.

Michael Albinus's avatar
Michael Albinus committed
744 745 746 747
+++
*** The user option 'tramp-ignored-file-name-regexp' allows to disable
Tramp for some look-alike remote file names.

748 749 750 751
+++
*** For some connection methods, like "su" or "sudo", the host name in
ad-hoc multi-hop file names must match the previous hop.

752
** Register
753
---
754 755 756
*** The return value of method 'register-val-describe' includes the
names of buffers shown by the windows of a window configuration.

757
---
758 759 760
** The options.el library has been removed.
It was obsolete since Emacs 22.1, replaced by customize.

761 762 763 764
** The tls.el and starttls.el libraries are now marked obsolete.
Use of built-in libgnutls based functionality (described in the Emacs
GnuTLS manual) is recommended instead.

765 766 767 768 769
** Message

+++
*** Messages can now be systematically encrypted
when the PGP keyring contains a public key for every recipient.  To
770
achieve this, add 'message-sign-encrypt-if-all-keys-available' to
771 772
'message-send-hook'.

773 774 775 776 777
---
*** When replying a message that have addresses on the form
'"foo@bar.com" <foo@bar.com>', Message will elide the repeated "name"
from the address field in the response.

778
---
779
*** The default of 'message-forward-as-mime' has changed from t to nil
780 781 782
as it has been reported that many recipients can't read forwards that
are formatted as MIME digests.

783
+++
Michael Albinus's avatar
Michael Albinus committed
784
*** 'message-forward-included-headers' has changed its default to
785 786
exclude most headers when forwarding.

787 788 789 790
** EasyPG

---
*** 'epa-pinentry-mode' is renamed to 'epg-pinentry-mode'.
791 792
It now applies to epg functions as well as epa functions.

793 794 795 796 797 798
---
*** The alias functions 'epa--encode-coding-string',
'epa--decode-coding-string', and 'epa--select-safe-coding-system' have
been removed.  Use 'encode-coding-string', 'decode-coding-string', and
'select-safe-coding-system' instead.

799 800 801 802 803 804 805
** Rmail

+++
*** New user option 'rmail-output-reset-deleted-flag'.
If this option is non-nil, messages appended to an output file by the
'rmail-output' command have their Deleted flag reset.

806 807 808 809
*** The command 'rmail-summary-by-senders' with an empty argument
selects the messages to summarize with a regexp that matches the
sender of the current message.

810 811 812 813 814 815 816 817 818 819
** Threads

+++
*** New variable 'main-thread' holds Emacs's main thread.
This is handy in Lisp programs that run on a non-main thread and want
to signal the main thread, e.g., when they encounter an error.

+++
*** 'thread-join' returns the result of the finished thread now.

820 821 822 823
+++
*** 'thread-signal' does not propagate errors to the main thread.
Instead, error messages are just printed in the main thread.

824 825 826
---
*** 'thread-alive-p' is now obsolete, use 'thread-live-p' instead.

827
+++
828 829 830 831 832
*** New command 'list-threads' shows Lisp threads.
See the current list of live threads in a tabulated-list buffer which
automatically updates.  In the buffer, you can use 's q' or 's e' to
signal a thread with quit or error respectively, or get a snapshot
backtrace with 'b'.
833

834 835 836 837 838 839
---
** thingatpt.el supports a new "thing" called 'uuid'.
A symbol 'uuid' can be passed to thing-at-point and it returns the
UUID at point.


840 841 842 843
** Interactive automatic highlighting

+++
*** 'highlight-regexp' can now highlight subexpressions.
844 845
The now command accepts a prefix numeric argument to choose the
subexpression.
846

847

848
* New Modes and Packages in Emacs 27.1
849

Stefan Monnier's avatar
Stefan Monnier committed
850 851
** multifile.el lets one setup multifile operations like search&replace

852
+++
853 854 855
** Emacs can now visit files in archives as if they were directories.
This feature uses Tramp and works only on systems which support GVFS,
i.e. GNU/Linux, roughly spoken.  See the chapter "(tramp) Archive file
856 857
names" in the Tramp manual for full documentation of these facilities.

João Távora's avatar
João Távora committed
858 859 860 861 862 863 864 865 866
+++
** New library for writing JSONRPC applications (https://jsonrpc.org)
The 'jsonrpc' library enables writing Emacs Lisp applications that
rely on this protocol.  Since the protocol is designed to be
transport-agnostic, the library provides an API to implement new
transport strategies as well as a separate API to use them.  A
transport implementation for process-based communication, such as is
used by the Language Server Protocol (LSP), is readily available.

867 868 869 870
+++
** Backtrace mode improves viewing of Elisp backtraces.
Backtrace mode adds pretty printing, fontification and ellipsis
expansion to backtrace buffers produced by the Lisp debugger, Edebug
871
and ERT.  See the node "Backtraces" in the Elisp manual for
872 873
documentation of the new mode and its commands.

Glenn Morris's avatar
Glenn Morris committed
874 875 876

* Incompatible Lisp Changes in Emacs 27.1

877 878 879
** define-fringe-bitmap is always defined, even when Emacs is built
without any GUI support.

880 881 882 883 884 885 886 887 888 889 890 891 892 893 894
---
** Just loading a theme's file no longer activates the theme's settings.
Loading a theme with 'M-x load-theme' still activates the theme, as it
did before.  However, loading the theme's file with "M-x load-file",
or using 'require' or 'load' in a Lisp program, doesn't actually apply
the theme's settings until you either invoke 'M-x enable-theme' or
type 'M-x load-theme'.  (In a Lisp program, calling 'enable-theme' or
invoking 'load-theme' with NO-ENABLE argument omitted or nil has the
same effect of activating a theme whose file has been loaded.)  The
special case of the 'user' theme is an exception: it is frequently
used for ad-hoc customizations, so the settings of that theme are by
default applied immediately.

The variable 'custom--inhibit-theme-enable' controls this behavior;
its default value changed in Emacs 27.1.
895

896
** The 'repetitions' argument of 'benchmark-run' can now also be a variable.
897

Glenn Morris's avatar
Glenn Morris committed
898 899 900 901 902 903 904 905 906 907
** The FILENAME argument to 'file-name-base' is now mandatory and no
longer defaults to 'buffer-file-name'.

---
** The function 'eldoc-message' now accepts a single argument.
Programs that called it with multiple arguments before should pass
them through 'format' first.  Even that is discouraged: for ElDoc
support, you should set 'eldoc-documentation-function' instead of
calling 'eldoc-message' directly.

908 909 910 911
** Old-style backquotes now generate an error.
They have been generating warnings for a decade.  To interpret
old-style backquotes as new-style, bind the new variable
'force-new-style-backquotes' to t.
Glenn Morris's avatar
Glenn Morris committed
912 913 914 915 916 917 918

** Defining a Common Lisp structure using 'cl-defstruct' or
'cl-struct-define' whose name clashes with a builtin type (e.g.,
'integer' or 'hash-table') now signals an error.

** When formatting a floating-point number as an octal or hexadecimal
integer, Emacs now signals an error if the number is too large for the
919
implementation to format.
Glenn Morris's avatar
Glenn Morris committed
920

921
---
Glenn Morris's avatar
Glenn Morris committed
922
** Some functions and variables obsolete since Emacs 22 have been removed:
923 924 925 926 927 928
archive-mouse-extract, assoc-ignore-case, assoc-ignore-representation,
backward-text-line, blink-cursor, bookmark-exit-hooks,
comint-use-prompt-regexp-instead-of-fields, compilation-finish-function,
count-text-lines, cperl-vc-header-alist, custom-face-save-command,
cvs-display-full-path, cvs-fileinfo->full-path, delete-frame-hook,
derived-mode-class, describe-char-after, describe-project,
Michael Albinus's avatar
Michael Albinus committed
929 930 931 932 933 934
desktop-basefilename, desktop-buffer-handlers, desktop-buffer-misc-functions,
desktop-buffer-modes-to-save, desktop-enable, desktop-load-default,
dired-omit-files-p, disabled-command-hook, dungeon-mode-map,
electric-nroff-mode, electric-nroff-newline, electric-perl-terminator,
focus-frame, forward-text-line, generic-define-mswindows-modes,
generic-define-unix-modes, generic-font-lock-defaults, goto-address-at-mouse,
935 936 937 938
highlight-changes-colours, ibuffer-elide-long-columns, ibuffer-hooks,
ibuffer-mode-hooks, icalendar-convert-diary-to-ical,
icalendar-extract-ical-from-buffer, imenu-always-use-completion-buffer-p,
ipconfig-program, ipconfig-program-options, isearch-lazy-highlight-cleanup,
Michael Albinus's avatar
Michael Albinus committed
939 940 941 942 943 944 945
isearch-lazy-highlight-initial-delay, isearch-lazy-highlight-interval,
isearch-lazy-highlight-max-at-a-time, iswitchb-use-fonts,
latin1-char-displayable-p, mouse-wheel-click-button, mouse-wheel-down-button,
mouse-wheel-up-button, new-frame, pascal-outline, process-kill-without-query,
recentf-menu-append-commands-p, rmail-pop-password,
rmail-pop-password-required, savehist-load, set-default-font,
spam-list-of-processors, speedbar-add-ignored-path-regexp,
946 947 948
speedbar-buffers-line-path, speedbar-ignored-path-expressions,
speedbar-ignored-path-regexp, speedbar-line-path, speedbar-path-line,
timer-set-time-with-usecs, tooltip-gud-display, tooltip-gud-modes,
949
tooltip-gud-toggle-dereference, unfocus-frame, unload-hook-features-list,
950 951 952
update-autoloads-from-directories, vc-comment-ring, vc-comment-ring-index,
vc-comment-search-forward, vc-comment-search-reverse, vc-comment-to-change-log,
vc-diff-switches-list, vc-next-comment, vc-previous-comment, view-todo,
Michael Albinus's avatar
Michael Albinus committed
953 954 955 956 957 958 959
x-lost-selection-hooks, x-sent-selection-hooks.

---
** Further functions and variables obsolete since Emacs 24 have been removed:
default-directory-alist, dired-default-directory,
dired-default-directory-alist, dired-enable-local-variables,
dired-hack-local-variables, dired-local-variables-file, dired-omit-here-always.
960

961 962 963 964 965
** garbage collection no longer treats miscellaneous objects specially;
they are now allocated like any other pseudovector.  As a result, the
'garbage-collect' and 'memory-use-count' functions no longer return a
'misc' component, and the 'misc-objects-consed' variable has been
removed.
966

967

968
* Lisp Changes in Emacs 27.1
Philipp Stephani's avatar
Philipp Stephani committed
969

970 971
** lookup-key can take a list of keymaps as argument.

972 973 974
+++
** 'condition-case' now accepts 't' to match any error symbol.

975 976 977
+++
** New function 'proper-list-p'.
Given a proper list as argument, this predicate returns its length;
978 979
otherwise, it returns nil.  'format-proper-list-p' is now an obsolete
alias for the new function.
980

Tom Tromey's avatar
Tom Tromey committed
981
+++
982 983 984 985 986 987 988 989 990 991 992 993
** Emacs Lisp integers can now be of arbitrary size.
Emacs uses the GNU Multiple Precision (GMP) library to support
integers whose size is too large to support natively.  The integers
supported natively are known as "fixnums", while the larger ones are
"bignums".  The new predicates 'bignump' and 'fixnump' can be used to
distinguish between these two types of integers.

All the arithmetic, comparison, and logical (a.k.a. "bitwise")
operations where bignums make sense now support both fixnums and
bignums.  However, note that unlike fixnums, bignums will not compare
equal with 'eq', you must use 'eql' instead.  (Numerical comparison
with '=' works on both, of course.)
Tom Tromey's avatar
Tom Tromey committed
994

995 996 997 998 999
Since large bignums consume a lot of memory, Emacs limits the size of
the largest bignum a Lisp program is allowed to create.  The
nonnegative value of the new variable 'integer-width' specifies the
maximum number of bits allowed in a bignum.  Emacs signals an integer
overflow error if this limit is exceeded.
1000

1001 1002 1003 1004 1005 1006 1007 1008
Several primitive functions formerly returned floats or lists of
integers to represent integers that did not fit into fixnums.  These
functions now simply return integers instead.  Affected functions
include functions like encode-char that compute code-points, functions
like file-attributes that compute file sizes and other attributes,
functions like process-id that compute process IDs, and functions like
user-uid and group-gid that compute user and group IDs.

1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023
+++
** Although the default timestamp format is still (HI LO US PS),
it is planned to change in a future Emacs version, to exploit bignums.
The documentation has been updated to mention that the timestamp
format may change and that programs should use functions like
format-time-string, decode-time, and encode-time rather than probing
the innards of a timestamp directly, or creating a timestamp by hand.

+++
** encode-time supports a new API (encode-time TIME &optional FORM).
This can convert decoded times and Lisp time values to Lisp timestamps
of various forms, including a new timestamp form (TICKS . HZ), where
TICKS is an integer and HZ is a positive integer denoting a clock
frequency.  The old encode-time API is still supported.

1024 1025 1026 1027 1028 1029
+++
** 'time-add', 'time-subtract', and 'time-less-p' now accept
infinities and NaNs too, and propagate them or return nil like
floating-point operators do.

+++
1030
** New function 'time-equal-p' compares time values for equality.
1031

1032
** define-minor-mode automatically documents the meaning of ARG.
1033

1034
+++
Eli Zaretskii's avatar
Eli Zaretskii committed
1035 1036 1037 1038
** The function 'recenter' now accepts an additional optional argument.
By default, calling 'recenter' will not redraw the frame even if
'recenter-redisplay' is non-nil.  Call 'recenter' with the new second
argument non-nil to force redisplay per 'recenter-redisplay's value.
1039

1040 1041 1042 1043
+++
** New functions 'major-mode-suspend' and 'major-mode-restore'.
Use them when switching temporarily to another major mode, e.g. for
'hexl-mode', or to switch between 'c-mode' and 'image-mode' in XPM.
1044

1045
+++
Eli Zaretskii's avatar
Eli Zaretskii committed
1046 1047 1048
** New macro 'dolist-with-progress-reporter'.
This works like 'dolist', but reports progress similar to
'dotimes-with-progress-reporter'.
1049

1050
+++
1051 1052 1053
** New hook 'after-delete-frame-functions'.
This works like 'delete-frame-functions', but runs after the frame to
be deleted has been made dead and removed from the frame list.
1054

1055 1056 1057 1058 1059
---
** The function 'provided-mode-derived-p' was extended to support aliases.
The function now returns non-nil when the argument MODE is derived
from any alias of any of MODES.

1060
+++
1061 1062 1063 1064
** New frame focus state inspection interface.
The hooks 'focus-in-hook' and 'focus-out-hook' are now obsolete.
Instead, attach to 'after-focus-change-function' using 'add-function'
and inspect the focus state of each frame using 'frame-focus-state'.
1065

1066
+++
1067 1068 1069
** Emacs now requests and recognizes focus-change notifications from TTYs.
On terminal emulators that support the feature, Emacs can now support
'focus-in-hook' and 'focus-out-hook' for TTY frames.
1070

1071
+++
1072 1073 1074
** Window-specific face remapping.
Face specifications (of the kind used in 'face-remapping-alist')
now support filters, allowing faces to vary between different windows
1075 1076
displaying the same buffer.  See the Info node "Face Remapping" of the
Emacs Lisp Reference manual for more detail.
1077

1078 1079 1080 1081 1082
+++
** Special handling of buffer-local 'window-size-change-functions'.
A buffer-local value of this hook is now run only if at least one
window showing the buffer has changed its size.

1083
+++
1084
** The function assoc-delete-all now takes an optional predicate argument.
1085

1086 1087
+++
** New function 'string-distance' to calculate the Levenshtein distance
Chen Bin's avatar
Chen Bin committed
1088 1089
between two strings.

1090 1091 1092
** 'print-quoted' now defaults to t, so if you want to see
(quote x) instead of 'x you will have to bind it to nil where applicable.

1093 1094 1095 1096 1097 1098 1099 1100 1101
+++
** Numbers formatted via %o or %x may now be formatted as signed integers.
This avoids problems in calls like (read (format "#x%x" -1)), and is
more compatible with bignums, a planned feature.  To get this
behavior, set the experimental variable binary-as-unsigned to nil,
and if the new behavior breaks your code please email
32252@debbugs.gnu.org.  Because %o and %x can now format signed
integers, they now support the + and space flags.

1102 1103 1104 1105 1106 1107 1108 1109
** To avoid confusion caused by "smart quotes", the reader signals an
error when reading Lisp symbols which begin with one of the following
quotation characters: ‘’‛“”‟〞"'.  A symbol beginning with such a
character can be written by escaping the quotation character with a
backslash.  For example:

    (read "smart") => (invalid-read-syntax "strange quote" "")
    (read "\\smart") == (intern "smart")
1110 1111 1112 1113 1114

+++
** Omitting variables after '&optional' and '&rest' is now allowed.
For example (defun foo (&optional)) is no longer an error.  This is
sometimes convenient when writing macros.  See the ChangeLog entry
1115
titled "Allow '&rest' or '&optional' without following variable
1116 1117
(Bug#29165)" for a full listing of which arglists are accepted across
versions.
1118

Michael Albinus's avatar
Michael Albinus committed
1119 1120 1121
** Internal parsing commands now use 'syntax-ppss' and disregard
'open-paren-in-column-0-is-defun-start'.  This affects mostly things like
'forward-comment', 'scan-sexps', and 'forward-sexp' when parsing backward.
1122 1123 1124
The new variable 'comment-use-syntax-ppss' can be set to nil to recover the old
behavior if needed.

1125
** The 'server-name' and 'server-socket-dir' variables are set when a
1126
socket has been passed to Emacs.
1127

1128
---
1129
** The 'file-system-info' function is now available on all platforms.
1130
instead of just Microsoft platforms.  This fixes a 'get-free-disk-space'
1131
bug on OS X 10.8 and later.
1132

Paul Eggert's avatar
Paul Eggert committed
1133 1134 1135
+++
** 'memory-limit' now returns a better estimate of memory consumption.

1136
+++
Michael Albinus's avatar
Michael Albinus committed
1137
** New macro 'combine-change-calls' arranges to call the change hooks
1138 1139 1140 1141 1142
('before-change-functions' and 'after-change-functions') just once
each around a sequence of lisp forms, given a region.  This is
useful when a function makes a possibly large number of repetitive
changes and the change hooks are time consuming.

1143 1144 1145 1146
---
** The function 'get-free-disk-space' returns now a non-nil value for
remote systems, which support this check.

1147 1148 1149 1150
+++
** 'eql', 'make-hash-table', etc. now treat NaNs consistently.
Formerly, some of these functions ignored signs and significands of
NaNs.  Now, all these functions treat NaN signs and significands as
1151 1152
significant.  For example, (eql 0.0e+NaN -0.0e+NaN) now returns nil
because the two NaNs have different signs; formerly it returned t.
1153 1154 1155
Also, Emacs now reads and prints NaN significands; e.g., if X is a
NaN, (format "%s" X) now returns "0.0e+NaN", "1.0e+NaN", etc.,
depending on X's significand.
1156

1157 1158 1159 1160 1161
+++
** The function 'make-string' accepts an additional optional argument.
If the optional third argument is non-nil, 'make-string' will produce
a multibyte string even if its second argument is an ASCII character.

1162
** (format "%d" X) no longer mishandles a floating-point number X that
1163
does not fit in a machine integer.
1164

Paul Eggert's avatar
Paul Eggert committed
1165 1166 1167 1168 1169 1170