NEWS

GNU Emacs NEWS -- history of user-visible changes.

Copyright (C) 2014-2016 Free Software Foundation, Inc.
See the end of the file for license conditions.

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

This file is about changes in Emacs version 25.

See file HISTORY for a list of GNU Emacs versions and release dates.
See files NEWS.24, NEWS.23, NEWS.22, NEWS.21, NEWS.20, NEWS.19, NEWS.18,
and NEWS.1-17 for changes in older Emacs versions.

You can narrow news to a specific version by calling 'view-emacs-news'
with a prefix argument or by typing C-u C-h C-n.

Temporary note:
+++ indicates that all necessary documentation updates 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,
otherwise leave it unmarked.


* Installation Changes in Emacs 25.1

+++
** Building Emacs now requires C99 or later.

+++
** Building Emacs now requires GNU make, version 3.81 or later.

+++
** New configure option --with-cairo.
This builds Emacs with Cairo drawing.  As a side effect, it provides
support for built-in printing, when Emacs was built with GTK+.
Cairo drawing is an experimental feature in Emacs, and subject to
change in future releases.

+++
** New configure option --with-modules.
This enables support for loading dynamic modules; see below.

---
** By default, Emacs no longer works on IRIX.  We expect that Emacs
users are not affected by this, as SGI stopped supporting IRIX in
December 2013.  If you are affected, please send a bug report.  You
should be able to work around the problem either by porting the Emacs
undumping code to GCC under IRIX, or by configuring --with-wide-int,
or by sticking with Emacs 24.4.

---
** The Emacs garbage collector assumes GC_MARK_STACK == GC_MAKE_GCPROS_NOOPS.
The GC_MAKE_GCPROS_NOOPS stack-marking variant has been the default
since Emacs 24.4, and the other variants were undocumented and were
obstacles to maintenance and development.  GC_MARK_STACK and its
related symbols have been removed from the C internals.

---
** 'configure' now prefers gnustep-config when configuring GNUstep.
If gnustep-config is not available, the old heuristics are used.

---
** 'configure' now prefers inotify to gfile for file notification,
unless gfile is explicitly requested via --with-file-notification='gfile'.

---
** 'configure' detects the kqueue file notification library on *BSD
and Mac OS X machines.

---
** The configure option '--with-pkg-config-prog' has been removed.
Use './configure PKG_CONFIG=/full/name/of/pkg-config' if you need to.

---
** The configure option '--with-mmdf' has been removed.
It was no longer useful, as it relied on libraries that are no longer
supported, and its presence led to confusion during configuration.
This affects only the 'movemail' utility; Emacs itself can still
process MMDF-format files as before.

+++
** The configure option '--enable-silent-rules' is now the default,
and silent rules are now quieter.  To get the old behavior where
'make' chatters a lot, configure with '--disable-silent-rules' or
build with 'make V=1'.

---
** The configure option '--with-gameuser' now allows you to specify a
group instead of a user if its argument is prefixed by ':' (a colon).
This will cause the game score files in ${localstatedir}/games/emacs
to be owned by that group, and the helper program for updating them to
be installed setgid.  The option now defaults to the 'games' group.

---
** The 'grep-changelog' script (and its manual page) are no longer included.
It has no particular connection to Emacs and has not changed in years,
so if you want to use it, you can always take a copy from an older Emacs.

---
** Emacs 25 comes with a new set of icons.
Various resolutions are available as etc/images/icons/hicolor/*/apps/emacs.png.
The old Emacs logo icons are available as 'emacs23.png' in the same location.

---
** New make target 'check-expensive' to run additional tests.
This includes all tests which run via "make check", plus additional
tests which take more time to perform.


* Startup Changes in Emacs 25.1

+++
** When Emacs is given a file as a command line argument and
'initial-buffer-choice' is non-nil, display both the file and
'initial-buffer-choice'.  When Emacs is given more than one file and
'initial-buffer-choice' is non-nil, show 'initial-buffer-choice'
and *Buffer List*.  This makes Emacs convenient to use from the
command line when 'initial-buffer-choice' is non-nil.

+++
** The value of 'initial-scratch-message' is now treated as a doc string
and can contain escape sequences for command keys, quotes, and the like.

---
** The default height of GUI frames was enlarged.
This is so there's enough space in the initial window to display the
optional text about recovering crashes sessions, without losing the
splash image display.


* Changes in Emacs 25.1

+++
** Xwidgets: a new feature for embedding native widgets inside Emacs buffers.
If you have gtk3 and webkitgtk3 installed, and Emacs was built with
xwidget support, you can access the embedded webkit browser with 'M-x
xwidget-webkit-browse-url'.  This opens a new buffer with the embedded
browser.  The buffer will have a new mode, 'xwidget-webkit-mode'
(similar to 'image-mode'), which supports the webkit widget.

+++
*** New functions for xwidget-webkit mode 'xwidget-webkit-insert-string',
'xwidget-webkit-adjust-size-dispatch', 'xwidget-webkit-back',
'xwidget-webkit-browse-url', 'xwidget-webkit-reload',
'xwidget-webkit-current-url', 'xwidget-webkit-scroll-backward',
'xwidget-webkit-scroll-forward', 'xwidget-webkit-scroll-down',
'xwidget-webkit-scroll-up'.

+++
** Emacs can now load shared/dynamic libraries (modules).
A dynamic Emacs module is a shared library that provides additional
functionality for use in Emacs Lisp programs, just like a package
written in Emacs Lisp would.  The functions 'load', 'require',
'load-file', etc. were extended to load such modules, as they do with
Emacs Lisp packages.  The new variable 'module-file-suffix' holds the
system-dependent value of the file-name extension ('.so' on Posix
hosts) of the module files.

A module should export a C-callable function named
'emacs_module_init', which Emacs will call as part of the call to
'load' or 'require' which loads the module.  It should also export a
symbol named 'plugin_is_GPL_compatible' to indicate that its code is
released under the GPL or compatible license; Emacs will refuse to
load modules that don't export such a symbol.

If a module needs to call Emacs functions, it should do so through the
API defined and documented in the header file 'emacs-module.h'.  Note
that any module that provides Lisp-callable functions will have to use
Emacs functions such as 'fset' and 'funcall', in order to register its
functions with the Emacs Lisp interpreter.

Modules can create 'user-ptr' Lisp objects that embed pointers to C
structs defined by the module.  This is useful for keeping around
complex data structures created by a module, to be passed back to the
module's functions.  User-ptr objects can also have associated
"finalizers" -- functions to be run when the object is GC'ed; this is
useful for freeing any resources allocated for the underlying data
structure, such as memory, open file descriptors, etc.  A new
predicate 'user-ptrp' returns non-nil if its argument is a 'user-ptr'
object.

Loadable modules in Emacs are an experimental feature, and subject to
change in future releases.  For that reason, their support is disabled
by default, and must be enabled by using the '--with-modules' option
at configure time.

+++
** Network security (TLS/SSL certificate validity and the like) is
added via the new Network Security Manager (NSM) and controlled via
the 'network-security-level' variable.

+++
** C-h l now also lists the commands that were run.

+++
** x-select-enable-clipboard is renamed select-enable-clipboard
and x-select-enable-primary is renamed select-enable-primary.
Additionally they both now apply to all systems (OSX, GNUstep, Windows, you
name it), with the proviso that on some systems (e.g. Windows)
select-enable-primary is ineffective since the system doesn't
have the equivalent of a primary selection.

+++
** New option 'switch-to-buffer-in-dedicated-window' allows you to
customize how 'switch-to-buffer' proceeds interactively when the
selected window is strongly dedicated to its buffer.

+++
** The option 'even-window-heights' has been renamed to
'even-window-sizes' and now handles window widths as well.

+++
** terpri gets an optional arg ENSURE to conditionally output a newline.

+++
** 'insert-register' now leaves point after the inserted text
when called interactively.  A prefix argument toggles this behavior.

+++
** The new variable 'term-file-aliases' replaces some files from lisp/term.
The function 'tty-run-terminal-initialization' consults this variable
when deciding what terminal-specific initialization code to run.

---
** New variable 'system-configuration-features', listing some of the
main features that Emacs was compiled with.  This is mainly intended
for use in Emacs bug reports.

+++
** A password is now hidden also when typed in batch mode.  Another
hiding character but the default '.' can be used by let-binding the
variable 'read-hide-char'.

+++
** The Emacs pseudo-random number generator can be securely seeded.
On system where Emacs can access the system entropy or some other
cryptographically secure random stream, it now uses that when 'random'
is called with its argument 't'.  This allows cryptographically strong
random values; in particular, the Emacs server now uses this facility
to produce its authentication key.

---
** New input methods: 'tamil-dvorak' and 'programmer-dvorak'.


* Editing Changes in Emacs 25.1

+++
** M-x suggests shorthands and ignores obsolete commands for completion.

** Changes in undo

+++
*** Successive single-char deletions are collapsed in the undo-log just like
successive char insertions.  Which commands invoke this behavior is
controlled by the new 'undo-auto-amalgamate' function.  See the node
"Undo" in the ELisp manual for more details.

+++
*** The heuristic used to insert 'undo-boundary' after each command
has changed, so that if a command causes changes in more than just the
current buffer, Emacs now calls 'undo-boundary' in every buffer
affected by the command.

+++
** New command 'comment-line' bound to 'C-x C-;'.

** New and improved facilities for inserting Unicode characters

---
*** Unicode names entered via C-x 8 RET now use substring completion by default.

+++
*** C-x 8 now has shorthands for several chars, such as U+2010
(HYPHEN), U+2011 (NON-BREAKING HYPHEN), and U+2012 (FIGURE DASH).  As
before, you can type C-x 8 C-h to list shorthands.

+++
*** New minor mode electric-quote-mode for using curved quotes as you
type.  See also the new variable 'text-quoting-style'.

---
** New minor mode global-eldoc-mode is enabled by default.

---
** Emacs now uses "bracketed paste mode" on text terminals that support it.
Bracketed paste mode causes text terminals to wrap pasted text in special
escape sequences that allow Emacs to tell the difference between text
you type and text you paste from other applications.  Emacs then
avoids interpreting each character in the pasted text as it does with
keyboard input, which results in a paste experience similar to that
under a window system, and significant performance improvements when
pasting large amounts of text.

Bracketed paste mode is disabled by default, so Emacs automatically
enables it at startup if the terminal supports it.

+++
** Emacs now supports the latest version of the UBA.
The Emacs implementation of the Unicode Bidirectional Algorithm (UBA)
was updated to support all the latest additions and changes introduced
in Unicode Standard versions 6.3, 7.0, and the latest Unicode 8.0.
This includes full support for directional isolates and the
Bidirectional Parentheses Algorithm (BPA) specified by these Unicode
standards.

+++
** You can access 'mouse-buffer-menu' (C-down-mouse-1) using C-f10.

+++
** New buffer-local 'electric-pair-local-mode'.

+++
** New variable 'fast-but-imprecise-scrolling' inhibits
fontification during full screen scrolling operations, giving less
hesitant operation during auto-repeat of C-v, M-v at the cost of
possible inaccuracies in the end position.

+++
** New documentation command 'describe-symbol'.
Works for functions, variables, faces, etc.  It is bound to 'C-h o' by
default.

+++
** New function 'custom-prompt-customize-unsaved-options' checks for
unsaved customizations and prompts user to customize (if found).  It
is intended for adding to 'kill-emacs-query-functions'.

+++
** The old 'C-x w' bindings in hi-lock-mode are officially deprecated
in favor of the global 'M-s h' bindings introduced in Emacs-23.1.
They'll disappear soon.


* Changes in Specialized Modes and Packages in Emacs 25.1

** Checkdoc

+++
*** New command 'checkdoc-package-keywords' checks if the
current package keywords are recognized.  Set the new option
'checkdoc-package-keywords-flag' to non-nil to make
'checkdoc-current-buffer' call this function automatically.

+++
*** New function 'checkdoc-file' checks for style errors.
It's meant for use together with 'compile':
emacs -batch --eval "(checkdoc-file \"subr.el\")"

** Desktop

---
*** The desktop format version has been upgraded from 206 to 208.
Although Emacs 25.1 can read a version 206 desktop, earlier Emacsen
cannot read a version 208 desktop.  To upgrade your desktop file, you
must explicitly request the upgrade, by C-u M-x desktop-save.  You are
recommended to do this as soon as you have firmly upgraded to Emacs
25.1 (or later).  Should you ever need to downgrade your desktop file
to version 206, you can do this with C-u C-u M-x desktop-save.

+++
** New function 'bookmark-set-no-overwrite' bound to C-x r M.
It raises an error if a bookmark of that name already exists,
unlike 'bookmark-set' which silently updates an existing bookmark.

** Gnus

+++
*** New user options 'mm-html-inhibit-images' and 'mm-html-blocked-images'
now control how mm-* functions fetch and display images in an HTML
message.  Gnus still uses 'gnus-inhibit-images' and 'gnus-blocked-images'
for that purpose, i.e., binds mm-html- variables with those gnus-
variables, but other packages do not have to bind gnus- variables now.

---
*** 'mm-inline-text-html-with-images' has been removed.
Use 'mm-html-inhibit-images' instead.  Note that the value is opposite
in meaning.

** IMAP

---
*** 'imap-ssl-program' has been removed, and imap.el uses the internal
GnuTLS encryption functions if possible.

** JSON

---
*** 'json-pretty-print' and 'json-pretty-print-buffer' now maintain
the ordering of object keys by default.

---
*** New commands 'json-pretty-print-ordered' and
'json-pretty-print-buffer-ordered' pretty prints JSON objects with
object keys sorted alphabetically.

** Prettify Symbols mode

+++
*** Prettify Symbols mode supports custom composition predicates.  By
overriding the default 'prettify-symbols-compose-predicate', modes can
specify in which contexts a symbol may be displayed as some Unicode
character.  'prettify-symbols-default-compose-p' is the default which
is suitable for most programming languages such as C or Lisp (but not
(La)TeX).

+++
*** Symbols can be unprettified while point is inside them.
New variable 'prettify-symbols-unprettify-at-point' configures this.

** Enhanced xterm support

---
*** The new variable 'xterm-screen-extra-capabilities' for configuring xterm.
This variable tells Emacs which advanced capabilities are available in
the xterm terminal emulator used to display Emacs text-mode frames.
The default is to check each capability, and use it if available.
(This variable was introduced in Emacs 24.1, but was not announced in
its NEWS.)

---
*** Killing text now also sets the CLIPBOARD/PRIMARY selection
in the surrounding GUI (using the OSC-52 escape sequence).  This only works
if your xterm supports it and enables the 'allowWindowOps' options (disabled
by default at least in Debian, for security reasons).

Similarly, you can yank the CLIPBOARD/PRIMARY selection (using the OSC-52
escape sequence) if your xterm has the feature enabled but for that you
additionally need to add 'getSelection' to 'xterm-extra-capabilities'.

+++
*** 'xterm-mouse-mode' now supports mouse-tracking (if your xterm supports it).

---
** The way to turn on and off 'save-place' mode has changed.
It is no longer sufficient to load the saveplace library and set
'save-place' non-nil.  Instead, use the two new minor modes:
'save-place-mode' turns on saving last place in every file, and
'save-place-local-mode' does that only for the file in whose buffer it
is invoked.  The 'save-place' variable is now an obsolete alias for
'save-place-mode', which replaces it, and 'toggle-save-place' is an
obsolete alias for the new 'save-place-local-mode' command.

** ERC

+++
*** ERC can now hide message types by network or channel.
'erc-hide-list' will hide all messages of the specified type, while
'erc-network-hide-list' and 'erc-channel-hide-list' will only hide the
specified message types for the respective specified targets.

---
*** Reconnection is now asynchronous.

---
*** Nick completion is now case-insensitive again after inadvertently
being made case-sensitive in Emacs 24.2.

** MPC

---
*** New commands, key binds, and menu items.

**** '<' and '>' for navigating previous and next tracks in playlist

**** New play/pause command 'mpc-toggle-play' bound to 's'

**** 'g' bound to new command 'mpc-seek-current' will navigate current
     track.

**** New commands 'mpc-toggle-{consume,repeat,single,shuffle}' for
     toggling playback modes.

---
*** Now supports connecting to a UNIX domain socket.

---
*** Looks at more image file names to use as album art.
Case-insensitively tries for .folder.png (freedesktop) and folder.jpg
(XP) in addition to cover.jpg.

---
*** Searches in more locations for MPD configuration files.
MPD supports the XDG base directory specification since version 0.17.6.

** Midnight-mode

---
*** 'midnight-mode' is now a proper minor mode.

---
*** clean-buffer-*-regexps can now specify buffers via predicate functions.

** package.el

+++
*** New "external" package status.
An external package is any installed package that's not built-in and
not from 'package-user-dir', which usually means it's from an entry in
'package-directory-list'.  They are treated much like built-in
packages, in that they cannot be deleted through the package menu and
are not considered for upgrades.

The effect is that a user can manually place a specific version of a
package inside 'package-directory-list' and the package menu will
always respect that.

+++
*** If a package is available on multiple archives and one has higher
priority (as per 'package-archive-priorities') only that one is
listed.  This can be configured with 'package-menu-hide-low-priority'.

+++
*** 'package-menu-toggle-hiding' now toggles the hiding of packages.
This includes the above-mentioned low-priority packages, as well as
available packages whose version is lower than the currently installed
version (which were previously impossible to display).
This allows users to downgrade a package if a lower version is
available.

---
*** When filtering the package menu, keywords starting with "arc:" or
"status:" represent package archive or status, respectively, instead
of actual keywords.

---
*** Most functions which involve downloading information now take an
ASYNC argument.  If it is non-nil, package.el performs the download(s)
asynchronously.

---
*** New variable 'package-menu-async' controls whether the
package-menu uses asynchronous downloads.

---
*** 'package-install-from-buffer' and 'package-install-file' work on directories.
This follows the same rules as installing from a .tar file, except the
-pkg file is optional.

---
*** Packages which are dependencies of other packages cannot be deleted.
The FORCE argument to 'package-delete' overrides this.

---
*** New custom variable 'package-selected-packages' tracks packages
which were installed by the user (as opposed to installed as
dependencies).  This variable can also be manually customized.

---
*** New command 'package-install-selected-packages' installs all
packages from 'package-selected-packages' which are currently missing.

---
*** 'package-install' function now takes a DONT-SELECT argument.  If
this function is called interactively or if DONT-SELECT is nil, add the
package being installed to 'package-selected-packages'.

---
*** New command 'package-autoremove' removes all packages which were
installed strictly as dependencies but are no longer needed.

+++
** Shell

When you invoke 'shell' interactively, the *shell* buffer will now
display in a new window.  However, you can customize this behavior via
the 'display-buffer-alist' variable.  For example, to get
the old behavior -- *shell* buffer displays in current window -- use
(add-to-list 'display-buffer-alist
     '("^\\*shell\\*$" . (display-buffer-same-window))).

** EIEIO
+++
*** The ':protection' slot option is not obeyed any more.
+++
*** The 'newname' argument to constructors is optional&deprecated.
If you need your objects to be named, do it by inheriting from 'eieio-named'.
+++
*** The <class>-list-p and <class>-child-p functions are declared obsolete.
+++
*** The <class> variables are declared obsolete.
+++
*** The <initarg> variables are declared obsolete.
+++
*** defgeneric and defmethod are declared obsolete.
Use the equivalent facilities from cl-generic.el instead.
+++
*** 'constructor' is now an obsolete alias for 'make-instance'.
--- 'pcase' accepts a new UPattern 'eieio'.

** ido

+++
*** New command 'ido-bury-buffer-at-head' bound to C-S-b
Bury the buffer at the head of 'ido-matches', analogous to how C-k
kills the buffer at head.

---
*** A prefix argument to 'ido-restrict-to-matches' will reverse its
meaning, and the list is restricted to those elements that do not
match the current input.

** Minibuffer

+++
*** You can use <UP> and <DOWN> arrow keys to move through history by lines.
The new commands 'next-line-or-history-element' and
'previous-line-or-history-element', bound to <UP> and <DOWN> in the
minibuffer, allow by-line movement through minibuffer history,
similarly to an ordinary buffer.  Only when point moves over
the bottom/top of the minibuffer it goes to the next/previous history
element.  'M-p' and 'M-n' still move directly to previous/next history
item as before.

** Search and Replace

+++
*** 'isearch' and 'query-replace' can now perform character folding in matches.
This is analogous to case folding, but instead of disregarding case
variants, it disregards wider classes of distinctions between similar
characters.  (Case folding is a special case of character folding.)
This means many characters in the search string will match entire
groups of characters instead of just themselves.

For instance, the ASCII double quote character " will match all
variants of double quotes, and the letter 'a' will match all of its
accented cousins, even those composed of multiple characters, as well
as many other symbols like U+249C (PARENTHESIZED LATIN SMALL LETTER
A).

Character folding is enabled by customizing 'search-default-mode' to
the value 'character-fold-to-regexp'.  You can also toggle character
folding in the middle of a search by typing 'M-s ''.

'query-replace' honors character folding if the new variable
'replace-character-fold' is customized to a non-nil value.

+++
*** New user option 'search-default-mode'.
This option specifies the default mode for Isearch.  The default
value, nil specifies that Isearch does literal searches (however,
'case-fold-search' and 'isearch-lax-whitespace' may still be applied,
as in previous Emacs versions).

+++
*** New function 'character-fold-to-regexp' can be used
by searching commands to produce a regexp matching anything that
character-folds into STRING.

+++
*** The new M-s M-w key binding uses eww to search the web for the
text in the region.  The search engine to use for this is specified by
the customizable variable 'eww-search-prefix'.

+++
*** Query-replace history is enhanced.
When query-replace reads the FROM string from the minibuffer, typing
'M-p' will now show previous replacements as "FROM SEP TO", where FROM
and TO are the original text and its replacement, and SEP is an arrow
string defined by the new variable 'query-replace-from-to-separator'.
To select a prior replacement, type 'M-p' until the desired
replacement appears in the minibuffer, and then exit the minibuffer by
typing RET.

** Calc
+++
*** If 'quick-calc' is called with a prefix argument, insert the
result of the calculation into the current buffer.

+++
** In Edebug, you can now set the initial mode with C-x C-a C-m.  With
this you can tell Edebug not to stop at the start of the first
instrumented function.

** ElDoc

+++
*** New minor mode 'global-eldoc-mode'
It is turned on by default, and affects '*scratch*' and other buffers
whose major mode supports Emacs Lisp.

---
*** 'eldoc-documentation-function' now defaults to 'ignore'

---
*** 'describe-char-eldoc' displays information about character at point,
and can be used as a default value of 'eldoc-documentation-function'.  It is
useful when, for example, one needs to distinguish various spaces - e.g.,
U+00A0 (NO-BREAK SPACE), U+2002 (EN SPACE), and U+2009 (THIN SPACE) - while
using mono-spaced font.

** eww

---
*** HTML can now be rendered using variable-width fonts.

+++
*** A new command 'F' ('eww-toggle-fonts') can be used to toggle
whether to use variable-pitch fonts or not.  The user can also
customize the 'shr-use-fonts' variable.

+++
*** A new command 'R' ('eww-readable') will try do identify the main