NEWS 26.3 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 30 31 32 33
** 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.

34 35 36 37 38 39 40
** 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.

41 42 43
** 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
44 45 46 47 48
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.

49

50
* Startup Changes in Emacs 27.1
51

52 53 54 55 56 57 58 59 60 61
+++
** 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).

+++
62
** Installed packages are now activated *before* loading the init file.
63 64 65 66
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'
67 68 69 70 71 72 73
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.
74
- you can use the new 'package-quickstart' so activation of packages does not
75
  need to pay attention to 'package-load-list' or 'package-user-dir' any more.
76

77

78
* Changes in Emacs 27.1
79

80 81 82 83 84 85
---
** New variable 'xft-ignore-color-fonts'.
Default t means don't try to load color fonts when using Xft, as they
often cause crashes.  Set it to nil if you really need those fonts.
(Bug#30874)

86 87 88 89 90 91
---
** 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.

92 93 94 95 96 97
---
** 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.

98 99 100 101 102 103 104 105 106
+++
** 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
107 108 109
+++
** New function 'logcount' calculates an integer's Hamming weight.

110 111 112 113 114 115 116 117
+++
** 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.

118
+++
119
** 'libxml-parse-xml-region' and 'libxml-parse-html' region take
120 121
a parameter that's called DISCARD-COMMENTS, but it really only
discards the top-level comment.  Therefore this parameter is now
122
obsolete, and the new utility function 'xml-remove-comments' can be
123 124 125
used to remove comments before calling the libxml functions to parse
the data.

126 127 128 129 130
+++
** 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.

131 132 133 134 135 136 137
+++
** 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\}

138 139 140
---
** The German prefix and postfix input methods now support Capital sharp S.

141

142
* Editing Changes in Emacs 27.1
143

144 145 146 147 148
---
** 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).

149
+++
150 151 152 153
** 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
154 155
typographic quotes, like this, in text modes, and in comments in
non-text modes.
156

157 158 159 160 161
---
** 'write-abbrev-file' now includes special properties.
'write-abbrev-file' now writes special properties like ':case-fixed'
for abbrevs that have them.

162
+++
163 164
** The new functions and commands 'text-property-search-forward' and
'text-property-search-backward' have been added.  These provide an
165 166
interface that's more like functions like @code{search-forward}.

Juri Linkov's avatar
Juri Linkov committed
167 168
---
** More commands support noncontiguous rectangular regions, namely
Michael Albinus's avatar
Michael Albinus committed
169
'upcase-dwim', 'downcase-dwim', 'replace-string', 'replace-regexp'.
Juri Linkov's avatar
Juri Linkov committed
170

Michael Albinus's avatar
Michael Albinus committed
171

172
* Changes in Specialized Modes and Packages in Emacs 27.1
173

174 175 176 177 178
** Browse-url
*** The function 'browse-url-emacs' can now visit a URL in selected window.
It now treats the optional 2nd argument to mean that the URL should be
shown in the currently selected window.

179 180 181 182 183 184 185 186 187 188 189
** Package
*** New 'package-quickstart' feature
When 'package-quickstart' is non-nil, package.el precomputes a big autoloads
file so that activation of packages can be done much faster, which can speed up
your startup significantly.
It also causes 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'.

190 191
** Ecomplete
*** The ecomplete sorting has changed to a decay-based algorithm.
192
This can be controlled by the new 'ecomplete-sort-predicate' variable.
193 194 195 196

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

Paul Eggert's avatar
Paul Eggert committed
197
** Gnus
198 199 200 201 202

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

Paul Eggert's avatar
Paul Eggert committed
203 204 205
*** The function 'gnus-score-find-favorite-words' has been renamed
from 'gnus-score-find-favourite-words'.

206 207 208 209
---
*** Gmane has been removed as an nnir backend, since Gmane no longer
has a search engine.

210
+++
211
*** Splitting mail on common mailing list headers has been added.  See
212
the concept index in the Gnus manual for the 'match-list' entry.
213

214
+++
215
*** nil is no longer an allowed value for 'mm-text-html-renderer'.
216

217
+++
218 219
*** A new Gnus summary mode command, 'S A'
('gnus-summary-attach-article') can be used to attach the current
220 221 222
article(s) to a pre-existing Message buffer, or create a new Message
buffer with the article(s) attached.

223 224 225
** erc

---
226
*** 'erc-button-google-url' has been renamed 'erc-button-search-url'
227 228
and its value has been changed to Duck Duck Go.

229 230 231
** eww/shr

*** When opening external links in eww/shr (typically with the
232 233
'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
234 235
has been executed.

Paul Eggert's avatar
Paul Eggert committed
236 237 238 239 240 241
** Htmlfontify
*** The functions 'hfy-color', 'hfy-color-vals' and
'hfy-fallback-color-values' and the variables 'hfy-fallback-color-map'
and 'hfy-rgb-txt-color-map' have been renamed from names that used
'colour' instead of 'color'.

242 243 244 245 246 247 248 249
+++
** 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.

250 251 252 253
** Smtpmail
Authentication mechanisms can be added via external packages, by
defining new cl-defmethod of smtpmail-try-auth-method.

254 255 256 257 258
** Footnote-mode
*** Support Hebrew-style footnotes
*** Footnote text lines are now aligned.
Can be controlled via the new variable 'footnote-align-to-fn-text'.

259 260 261 262 263 264 265
** 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'.

266 267 268
---
*** CSS mode, SCSS mode, and Less CSS mode now have support for Imenu.

269 270 271 272 273 274 275
** SGML mode

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

276 277 278 279 280 281 282
** 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.

283 284
** Help

285 286 287 288 289 290 291
---
*** 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'.
292

293 294 295 296
---
*** The list of help commands produced by 'C-h C-h' ('help-for-help')
can now be searched via 'C-s'.

297 298 299 300 301
** Ibuffer

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

302 303
** Search and Replace

Juri Linkov's avatar
Juri Linkov committed
304 305
+++
*** New isearch bindings.
306

Juri Linkov's avatar
Juri Linkov committed
307
'C-M-w' in isearch changed from isearch-del-char to the new function
308 309
isearch-yank-symbol-or-char.  isearch-del-char is now bound to
'C-M-d'.
Juri Linkov's avatar
Juri Linkov committed
310

311
+++
312 313 314 315 316 317
*** '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
318 319 320 321
---
*** Isearch now remembers the regexp-based search mode for words/symbols
and case-sensitivity together with search strings in the search ring.

322 323 324 325
** Edebug

+++
*** The runtime behavior of Edebug's instrumentation can be changed
326 327
using the new variables 'edebug-behavior-alist',
'edebug-after-instrumentation-function' and
328
'edebug-new-definition-function'.  Edebug's behavior can be changed
329 330
globally or for individual definitions.

331 332
** Enhanced xterm support

Mark Oteiza's avatar
Mark Oteiza committed
333 334 335
*** New variable 'xterm-set-window-title' controls whether Emacs sets
the XTerm window title.  This feature is experimental and is disabled
by default.
336

337 338
** Gamegrid

339 340
** grep

341
+++
342 343
*** rgrep, lgrep and zrgrep now hide part of the command line
that contains a list of ignored directories and files.
344 345 346 347
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.
348

Paul Pogonyshev's avatar
Paul Pogonyshev committed
349 350 351 352 353 354
** ERT

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

355 356
---
*** Gamegrid now determines its default glyph size based on display
357
dimensions, instead of always using 16 pixels.  As a result, Tetris,
358 359
Snake and Pong are more playable on HiDPI displays.

360 361 362 363 364 365
** Filecache

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

366 367 368 369
** New macros 'thunk-let' and 'thunk-let*'.
These macros are analogue to 'let' and 'let*', but create bindings that
are evaluated lazily.

370 371
** next-error

372
+++
373
*** New customizable variable 'next-error-find-buffer-function'.
374 375 376 377 378 379 380 381 382
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'.
383 384 385

** nxml-mode

Eli Zaretskii's avatar
Eli Zaretskii committed
386 387
---
*** The default value of 'nxml-sexp-element-flag' is now t.
388 389 390 391
This means that pressing C-M-SPACE now selects the entire tree by
default, and not just the opening element.


392 393 394 395 396 397 398 399 400
** 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
401 402
---
*** The function 'eshell-uniquify-list' has been renamed from
Paul Eggert's avatar
Paul Eggert committed
403 404
'eshell-uniqify-list'.

405 406 407 408
*** 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.

Paul Eggert's avatar
Paul Eggert committed
409 410 411 412
** Pcomplete
*** The function 'pcomplete-uniquify-list' has been renamed from
'pcomplete-uniqify-list'.

Michael Albinus's avatar
Michael Albinus committed
413 414 415 416 417 418

** Auth-source

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

419 420 421 422 423 424
** Tramp

+++
*** New connection method "owncloud", which allows to access OwnCloud
or NextCloud hosted files and directories.

Michael Albinus's avatar
Michael Albinus committed
425 426 427
+++
*** Validated passwords are saved by auth-source backends which support this.

Michael Albinus's avatar
Michael Albinus committed
428 429 430 431
+++
*** The user option 'tramp-ignored-file-name-regexp' allows to disable
Tramp for some look-alike remote file names.

432 433 434 435
---
** The options.el library has been removed.
It was obsolete since Emacs 22.1, replaced by customize.

436

437 438 439 440 441
** Message

+++
*** Messages can now be systematically encrypted
when the PGP keyring contains a public key for every recipient.  To
442
achieve this, add 'message-sign-encrypt-if-all-keys-available' to
443 444
'message-send-hook'.

445 446 447 448 449
---
*** 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.

450
---
451
*** The default of 'message-forward-as-mime' has changed from t to nil
452 453 454
as it has been reported that many recipients can't read forwards that
are formatted as MIME digests.

455
+++
Michael Albinus's avatar
Michael Albinus committed
456
*** 'message-forward-included-headers' has changed its default to
457 458
exclude most headers when forwarding.

459 460 461 462
** EasyPG

---
*** 'epa-pinentry-mode' is renamed to 'epg-pinentry-mode'.
463 464
It now applies to epg functions as well as epa functions.

465 466 467 468 469 470
---
*** 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.

471
* New Modes and Packages in Emacs 27.1
472

473
+++
474 475 476
** 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
477 478
names" in the Tramp manual for full documentation of these facilities.

Glenn Morris's avatar
Glenn Morris committed
479 480 481

* Incompatible Lisp Changes in Emacs 27.1

482
** The 'repetitions' argument of 'benchmark-run' can now also be a variable.
Glenn Morris's avatar
Glenn Morris committed
483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504
** 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.

** Old-style backquotes now generate an error.  They have been
generating warnings for a decade.  To interpret old-style backquotes
as new-style, bind the new variable 'force-new-style-backquotes' to t.

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

** When formatting a floating-point number as an octal or hexadecimal
integer, Emacs now signals an error if the number is too large for the
implementation to format (Bug#30408).

505 506 507 508
+++
** The Lisp reader now signals an overflow for plain decimal integers
that do not end in '.' and are outside Emacs range.  Formerly the Lisp
reader silently converted them to floating-point numbers, and signaled
509 510 511 512
overflow only for integers with a radix that are outside machine range.
To get the old behavior, set the new, experimental variable
read-integer-overflow-as-float to t and please email
30408@debbugs.gnu.org if you need that.  (Bug#30408).
513

514
---
Glenn Morris's avatar
Glenn Morris committed
515
** Some functions and variables obsolete since Emacs 22 have been removed:
516 517 518 519 520 521
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
522 523 524 525 526 527
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,
528 529 530 531
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
532 533 534 535 536 537 538
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,
539 540 541
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,
542
tooltip-gud-toggle-dereference, unfocus-frame, unload-hook-features-list,
543 544 545
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
546 547 548 549 550 551 552
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.
553

554
** The function 'display-buffer-in-major-side-window' no longer exists.
555
It has been renamed as internal function 'window--make-major-side-window',
556
however applications should instead call 'display-buffer-in-side-window'
557
(passing the SIDE and SLOT parameters as elements of ALIST).  This approach
558 559 560
is backwards-compatible with versions of Emacs in which the old function
exists.  See the node "Displaying Buffers in Side Windows" in the ELisp
manual for more details.
561

562
* Lisp Changes in Emacs 27.1
Philipp Stephani's avatar
Philipp Stephani committed
563

564 565 566
+++
** New function assoc-delete-all.

567 568
+++
** New function 'string-distance' to calculate the Levenshtein distance
Chen Bin's avatar
Chen Bin committed
569 570
between two strings.

571 572 573
** '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.

574 575 576 577 578 579 580 581
** 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")
582 583 584 585 586

+++
** 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
587 588 589
titled "Allow `&rest' or `&optional' without following variable
(Bug#29165)" for a full listing of which arglists are accepted across
versions.
590

Michael Albinus's avatar
Michael Albinus committed
591 592 593
** 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.
594 595 596
The new variable 'comment-use-syntax-ppss' can be set to nil to recover the old
behavior if needed.

597
** The 'server-name' and 'server-socket-dir' variables are set when a
Michael Albinus's avatar
Michael Albinus committed
598
socket has been passed to Emacs (Bug#24218).
599

600
---
601
** The 'file-system-info' function is now available on all platforms.
602
instead of just Microsoft platforms.  This fixes a 'get-free-disk-space'
603 604
bug on OS X 10.8 and later (Bug#28639).

605
+++
Michael Albinus's avatar
Michael Albinus committed
606
** New macro 'combine-change-calls' arranges to call the change hooks
607 608 609 610 611
('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.

612 613 614 615
---
** The function 'get-free-disk-space' returns now a non-nil value for
remote systems, which support this check.

616 617 618 619 620
+++
** 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.

621 622 623
** (format "%d" X) no longer mishandles a floating-point number X that
does not fit in a machine integer (Bug#30408).

624 625 626 627
** New JSON parsing and serialization functions 'json-serialize',
'json-insert', 'json-parse-string', and 'json-parse-buffer'.  These
are implemented in C using the Jansson library.

628 629
** Mailcap

630
---
631
*** The new function 'mailcap-file-name-to-mime-type' has been added.
632 633 634
It's a simple convenience function for looking up MIME types based on
file name extensions.

635 636 637 638 639 640 641
*** The default way the list of possible external viewers for MIME
types is sorted and chosen has changed.  Earlier, the most specific
viewer was chosen, even if there was a general override in ~/.mailcap.
For instance, if /etc/mailcap has an entry for image/gif, that one
will be chosen even if you have an entry for image/* in your
~/.mailcap file.  But with the new method, entries from ~/.mailcap
overrides all system and Emacs-provided defaults.  To get the old
642
method back, set 'mailcap-prefer-mailcap-viewers' to nil.
643 644 645 646 647 648 649 650


** URL

*** The file: handler no longer looks for index.html in directories if
you ask it for a file:///dir URL.  Since this is a low-level library,
such decisions (if they are to be made at all) are left to
higher-level functions.
651 652


653 654 655
** image-mode

*** image-mode started using ImageMagick by default for all images
656
some years back.  It now respects 'imagemagick-types-inhibit' as a way
657 658 659
to disable that.


660
+++
661 662 663
** The new function 'read-answer' accepts either long or short answers
depending on the new customizable variable 'read-answer-short'.

664 665 666 667
** The function 'load' now behaves correctly when loading modules.
Specifically, it puts the module name into 'load-history', prints
loading messages if requested, and protects against recursive loads.

668 669 670 671 672
+++
** The function 'read-variable' now uses its own history list.
The history of variable names read by 'read-variable' is recorded in
the new variable 'custom-variable-history'.

673 674 675 676 677 678 679
---
** The function 'string-to-unibyte' is no longer declared obsolete.
We have found that there are legitimate use cases for this function,
where there's no better alternative.  We believe that the incorrect
uses of this function all but disappeared by now, so we are
un-obsoleting it.

680

681
* Changes in Emacs 27.1 on Non-Free Operating Systems
682

683 684 685 686
---
** Battery status is now supported in all Cygwin builds.
Previously it was supported only in the Cygwin-w32 build.

687 688 689
** Emacs now handles key combinations involving the macOS "command"
and "option" modifier keys more correctly.

690 691 692
** The special handling of 'frame-title-format' on NS where setting it
to 't' would enable the macOS proxy icon has been replaced with a
separate variable, 'ns-use-proxy-icon'.  'frame-title-format' will now
693 694
work as on other platforms.

695 696 697 698 699 700 701
---
** New primitive 'w32-read-registry'.
This primitive lets Lisp programs access the MS-Windows Registry by
retrieving values stored under a given key.  It is intended to be used
for supporting features such as XDG-like location of important files
and directories.

702

Dave Love's avatar
#  
Dave Love committed
703
----------------------------------------------------------------------
704
This file is part of GNU Emacs.
Dave Love's avatar
#  
Dave Love committed
705

706
GNU Emacs is free software: you can redistribute it and/or modify
707
it under the terms of the GNU General Public License as published by
708 709
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
710 711 712 713 714

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
Dave Love's avatar
#  
Dave Love committed
715

716
You should have received a copy of the GNU General Public License
717
along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
Dave Love's avatar
#  
Dave Love committed
718

719

Dave Love's avatar
#  
Dave Love committed
720
Local variables:
721
coding: utf-8
Dave Love's avatar
#  
Dave Love committed
722 723 724
mode: outline
paragraph-separate: "[ 	]*$"
end: