NEWS

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

Copyright (C) 2017-2019 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 27.

See file HISTORY for a list of GNU Emacs versions and release dates.
See files NEWS.26, NEWS.25, ..., 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,


* Installation Changes in Emacs 27.1

** 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.
The new 'configure' option '--without-libgmp' uses mini-gmp even if a
suitable libgmp is available.

** Emacs can now use HarfBuzz as its shaping engine.
The new configure option '--with-harfbuzz' adds support for the
HarfBuzz text shaping engine.  It is on by default; use './configure
--without-harfbuzz' to build without it.  The HarfBuzz text shaping is
available via new font backend drivers 'xfthb' and 'ftcrhb' for Xft
and Cairo drawings, respectively, and via the 'harfbuzz' backend on
MS-Windows.  The Harfbuzz text shaping is preferred to the previously
supported ones, so the font backends that use older shaping engines
(FLT on GNU and Unix systems and Uniscribe on MS-Windows) are not
enabled by default; they can be enabled via the 'font-backend' frame
parameter or via X resources.

** 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.

** Emacs no longer defaults to using ImageMagick to display images,
due to security and stability concerns.  To override the default, use
'configure --with-imagemagick'.

** Several configure options now accept an option-argument 'ifavailable'.
For example, './configure --with-xpm=ifavailable' now configures Emacs
to attempt to use libxpm but to continue building even if libxpm is
absent.  The other affected options are '--with-gif', '--with-gnutls',
'--with-jpeg', '--with-png', and '--with-tiff'.

** 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.

** 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.

** 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
catch typos and supports '-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.

+++
** Emacs now uses a "portable dumper" instead of unexec.
This improves compatibility with memory allocation on modern systems,
and in particular better supports the Address Space Layout
Randomization (ASLR) feature, a security technique used by most modern
operating systems.

Portable dumping can be disabled at configure time via the configure
option '--with-dumping=unexec' (but we don't recommend that, unless
the portable dumping doesn't work on your system for some
reason---please report such systems to the Emacs developers as bugs).

When built with the portable dumping support (which is the default),
Emacs looks for the 'emacs.pdmp' file, generated during the build, in
its data directory at startup, and loads the dumped state from there.
The new command-line argument '--dump-file=FILE' allows to specify a
non-default '.pdmp' file to load the state from; see the node "Initial
Options" in the Emacs manual for more information.

+++
** The new configure option '--enable-checking=structs' attempts to
check that the portable dumper code has been updated to match the last
change to one of the data structures that it relies on.

+++
** The configure options '--enable-checking=conslist' and
'--enable-checking=xmallocoverrun' have been withdrawn.  The former
made Emacs irredeemably slow, and the latter made it crash.  Neither
option was useful with modern debugging tools such as AddressSanitizer.
(See etc/DEBUG for the details of using the modern replacements of the
removed configure options.)

+++
** The distribution tarball now has test cases; 'make check' runs them.
This is intended mostly to help developers.

---
** Emacs now requires GTK 2.24 and GTK 3.10 for the GTK 2 and GTK 3
builds respectively.


* Startup Changes in Emacs 27.1

+++
** 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).

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.

+++
** Installed packages are now activated *before* loading the init file.
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'
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.
- You can use the new 'package-quickstart' so activation of packages
  does not need to pay attention to 'package-load-list' or
  'package-user-dir' any more.

---
** 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.)

+++
** New option 'help-enable-completion-auto-load'.
This allows disabling the new feature introduced in Emacs 26.1 which
loads files during completion of 'C-h f' and 'C-h v' according to
'definition-prefixes'.


* Changes in Emacs 27.1

** emacsclient

+++
*** emacsclient now supports the 'EMACS_SOCKET_NAME' environment variable.
The behavior is identical to 'EMACS_SERVER_FILE', in that the
command-line value specified via '--socket-name' will override the
environment, and the natural default to 'TMPDIR', then "/tmp", continues
to apply.

+++
*** Emacs and emacsclient now default to "$XDG_RUNTIME_DIR/emacs"
as the directory for client/server sockets, if Emacs is running
under an X Window System desktop that sets the 'XDG_RUNTIME_DIR'
environment variable to indicate where session sockets should go.
To get the old, less-secure behavior, you can set the
'EMACS_SOCKET_NAME' environment variable to an appropriate value.

---
*** When run by root, emacsclient no longer connects to non-root sockets.
(Instead you can use Tramp methods to run root commands in a non-root Emacs.)

---
** Control of the threshold for using the 'distant-foreground' color.
The threshold for color distance below which the 'distant-foreground'
color of the face will be used instead of the foreground color can now
be controlled via the new variable 'face-near-same-color-threshold'.
The default value is 30000, as the previously hard-coded threshold.

+++
** The function 'read-passwd' uses "*" as default character to hide passwords.

** Lexical binding is now used when evaluating interactive Elisp forms.
More specifically, lexical-binding is now used for 'M-:', '--eval', as
well as in the "*scratch*" and "*ielm*" buffers.

---
** 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.

---
** Show mode line 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.

+++
** 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.

+++
** New function 'logcount' calculates an integer's Hamming weight.

+++
** 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.

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

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

+++
** 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).

+++
** Native GnuTLS connections can now use client certificates.
Previously, this support was only available when using the external
'gnutls-cli' command.  Call 'open-network-stream' with
':client-certificate t' to trigger looking up of per-server
certificates via 'auth-source'.

+++
** 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.

+++
** 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\}

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

---
** New input methods 'hawaiian-postfix' and 'hawaiian-prefix'.

---
** New input methods for several variants of the Sami language.
The Sami input methods include: 'norwegian-sami-prefix',
'bergsland-hasselbrink-sami-prefix', 'southern-sami-prefix',
'ume-sami-prefix', 'northern-sami-prefix', 'inari-sami-prefix',
'skolt-sami-prefix', and 'kildin-sami-prefix'.

+++
** In Japanese environments that do not specify encodings and are not
based on MS-Windows, the default encoding is now utf-8 instead of
japanese-iso-8bit.

+++
** 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.

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

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

---
** 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.

+++
** New variable 'emacs-repository-branch'.
It reports the git branch from which Emacs was built.

+++
** New user option 'switch-to-buffer-obey-display-actions'.
When non-nil, 'switch-to-buffer' uses 'pop-to-buffer-same-window' that
respects display actions specified by 'display-buffer-alist' and
'display-buffer-overriding-action'.

** New 'flex' completion style
An implementation of popular "flx/fuzzy/scatter" completion which
matches strings where the pattern appears as a subsequence.  Put
simply, makes "foo" complete to both "barfoo" and "frodo".  Add 'flex'
to 'completion-styles' or 'completion-category-overrides' to use it.

** Connection-local variables

+++
*** Connection-local variables are applied by default like file-local
and directory-local variables.

+++
*** The macro 'with-connection-local-variables' has been renamed from
'with-connection-local-profiles'.  No argument PROFILES needed any longer.

---
** New variable 'next-error-verbose' controls when 'next-error' outputs
a message about the error locus.

---
** New variable 'grep-search-path' defines the directories searched for
grep hits (this used to be controlled by 'compilation-search-path').

---
** New variable 'emacs-lisp-compilation-search-path' defines the
directories searched for byte-compiler error messages (this used to
be controlled by 'compilation-search-path').

** Multicolor fonts such as "Noto Color Emoji" can be displayed on
Emacs configured with Cairo drawing and linked with cairo >= 1.16.0.

+++
** Emacs now optionally displays a fill column indicator.

This is similar to what 'fill-column-indicator' package provides, but
much faster and compatible with 'show-trailing-whitespace'.

Customize the buffer-local variables 'display-fill-column-indicator'
and 'display-fill-column-indicator-character' to activate the
indicator.

The indicator is not displayed at all in minibuffer windows and
in tooltips, as it is not useful there.

There are 2 new buffer local variables and 1 face to customize this
mode they are described in the manual "(emacs) Display".

+++
** 'progress-reporter-update' accepts a suffix string to display.



* Editing Changes in Emacs 27.1

+++
** New command 'make-empty-file'.

---
** 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).

+++
** 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
typographic quotes, “like this”, in text modes, and in comments in
non-text modes.

---
** 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.

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

+++
** '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.

+++
** The new functions and commands 'text-property-search-forward' and
'text-property-search-backward' have been added.  These provide an
interface that's more like functions like 'search-forward'.

---
** More commands support noncontiguous rectangular regions, namely
'upcase-dwim', 'downcase-dwim', 'replace-string', 'replace-regexp'.

+++
** 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.

---
** '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
the node "(emacs) Directory Variables" of the user manual.

+++
** Network connections using 'local' can now use IPv6.
'make-network-process' now uses the correct loopback address when
asked to use ':host 'local' and ':family 'ipv6'.

+++
** The new function 'replace-region-contents' replaces the current
region using a given replacement-function in a non-destructive manner
(in terms of 'replace-buffer-contents').

+++
** The command 'replace-buffer-contents' now has two optional
arguments mitigating performance issues when operating on huge
buffers.

+++
** The command 'delete-indentation' now operates on the active region.
If the region is active, the command joins all the lines in the
region.  When there's no active region, the command works on the
current and the previous or the next line, as before.


* Changes in Specialized Modes and Packages in Emacs 27.1

** compile.el
---
*** In 'compilation-error-regexp-alist', 'line' (and 'end-line') can
be functions.

** cl-lib.el
+++
*** 'cl-defstruct' has a new ':noinline' argument to prevent inlining
its functions.

** doc-view.el
*** New commands 'doc-view-presentation' and 'doc-view-fit-window-to-page'.
*** Added support for password-protected PDF files

** Ido
*** New user option 'ido-big-directories' to mark directories whose
names match certain regular expressions as big.  Ido won't attempt to
list the contents of such directories when completing file names.

** Minibuffer

---
*** Minibuffer now uses 'minibuffer-message' to display error messages
at the end of the active minibuffer.

** map.el
*** Now also understands plists.
*** Now defined via generic functions that can be extended via 'cl-defmethod'.
*** Deprecate the 'map-put' macro in favor of a new 'map-put!' function.
*** 'map-contains-key' now returns a boolean rather than the key.
*** Deprecate the 'testfn' args of 'map-elt' and 'map-contains-key'.
*** New generic function 'map-insert'.

+++
** seq.el
New convenience functions 'seq-first' and 'seq-rest' give easy access
to respectively the first and all but the first elements of sequences.

The new predicate function 'seq-contains-p' should be used instead of
the now obsolete 'seq-contains'.

---
** 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.

** Windmove

*** 'windmove-create-window' when non-nil makes a new window on moving off
the edge of the frame.

*** Windmove supports directional window display and selection.
The new command 'windmove-display-default-keybindings' binds default
keys with provided modifiers (by default, Shift-Meta) to the commands
that display the next buffer in the window at the specified direction.
This is like 'windmove-default-keybindings' that binds keys to commands
that select the window in the specified direction, but additionally it
displays the buffer from the next command in that window.  For example,
'S-M-right C-h i' displays the "*Info*" buffer in the right window,
creating the window if necessary.  A special key can be customized to
display the buffer in the same window, for example, 'S-M-0 C-h e'
displays the "*Messages*" buffer in the same window.

*** Windmove also supports directional window deletion.
The new command 'windmove-delete-default-keybindings' binds default
keys with provided prefix (by default, 'C-x') and modifiers (by default,
'Shift') to the commands that delete the window in the specified
direction.  For example, 'C-x S-down' deletes the window below.
With a prefix arg 'C-u', also kills the buffer in that window.
With 'M-0', deletes the selected window and selects the window
that was in the specified direction.

*** New command 'windmove-swap-states-in-direction' binds default keys
to the commands that swap the states of the selected window with the
window in the specified direction.

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

** project.el

*** New commands 'project-search' and 'project-query-replace-regexp'.

*** New customizable variable 'project-read-file-name-function'.

** Etags

+++
*** 'next-file' is now an obsolete alias of 'tags-next-file'.

*** 'tags-loop-revert-buffers' is an obsolete alias of
'fileloop-revert-buffers'.

*** The 'tags-loop-continue' function along with the
'tags-loop-operate' and 'tags-loop-scan' variables are now obsolete;
use the new 'fileloop-initialize' and 'fileloop-continue' functions
instead.

** bibtex

---
*** New commands 'bibtex-next-entry' and 'bibtex-previous-entry'.
In 'bibtex-mode-map', 'forward-paragraph' and 'backward-paragraph' are
remapped to these, respectively.

** Dired

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

** Find-Dired

*** New customizable variable 'find-dired-refine-function'.
The default value is 'find-dired-sort-by-filename'.

** Change Logs and VC

*** 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.

*** New customizable variable 'vc-find-revision-no-save'.
With non-nil, 'vc-find-revision' doesn't write the created buffer to file.

*** 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.

*** 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.

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

---
*** 'vc-hg' now invokes 'smerge-mode' when visiting files.
Code that attempted to invoke 'smerge-mode' when visiting an Hg file
with conflicts existed in earlier versions of Emacs, but incorrectly
never detected a conflict due to invalid assumptions about cached
values.

+++
*** 'C-u C-x v D' ('vc-root-version-diff') prompts for two revisions
and compares their entire trees.

*** New user option 'vc-hg-revert-switches' specifies switches to pass
to Hg revert.

*** 'C-x v M D' ('vc-diff-mergebase') and 'C-x v M L' ('vc-log-mergebase')
print diffs and logs between the merge base (common ancestor) of two
given revisions.

** Diff mode
+++
*** Hunks are now automatically refined by font-lock.
To disable refinement, set the new user option 'diff-refine' to nil.
To get back the old behavior where hunks are refined as you navigate
through a diff, set 'diff-refine' to the symbol 'navigate'.

+++
*** 'diff-auto-refine-mode' is deprecated in favor of 'diff-refine'.
It is no longer enabled by default and binding it no longer has any
effect.

+++
*** Better syntax highlighting of Diff hunks.
Fragments of source in Diff hunks are now by default highlighted
according to the appropriate major mode.  Customize the new option
'diff-font-lock-syntax' to nil to disable this.

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

+++
*** Prefix arg of 'diff-goto-source' means jump to the old revision
of the file under version control if point is on an old changed line,
or to the new revision of the file otherwise.

** Texinfo

+++
*** New function for inserting '@pxref', '@xref', or '@ref' commands.
The function 'texinfo-insert-dwim-@ref', bound to 'C-c C-c r' by
default, inserts one of three types of references based on the text
surrounding point, namely '@pxref' near a parenthesis, '@xref' at the
start of a sentence or at '(point-min)', else '@ref'.

** 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.

** Comint

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

+++
*** '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.

** SQL

*** SQL Indent Minor Mode
SQL Mode now supports the ELPA 'sql-indent' package for assisting
sophisticated SQL indenting rules.  Note, however, that 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.
The 'sql-indent' package from ELPA must be installed to get the
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 you have existing customizations to these variables,
you should make sure that the new default entry is included.

*** Connection Wallet
Database passwords can now by stored in NETRC or JSON data files that
may optionally be encrypted. When establishing an interactive session
with the database via 'sql-connect' or a product specific function,
like 'sql-mysql' or 'my-postgres', the password wallet will be
searched for the password. The 'sql-product', 'sql-server',
'sql-database', and the 'sql-username' will be used to identify the
appropriate authorization. This eliminates the discouraged practice of
embedding database passwords in your Emacs initialization.

See the 'auth-source' module for complete documentation on the file
formats.  By default, the wallet file is expected to be in the
'user-emacs-directory', named 'sql-wallet' or '.sql-wallet', with
'.json' (JSON) or no (NETRC) suffix.  Both file formats can optionally
be encrypted with GPG by adding an additional '.gpg' suffix.

** Term

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

** Flymake

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

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

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

+++
*** 'flymake-start-syntax-check-on-newline' is now obsolete,
use 'post-self-insert-hook' to check on newline.

** Ruby

*** The Rubocop Flymake diagnostic function will only run Lint cops if
it can't find the config file.

*** Rubocop is called with 'bundle exec' if Gemfile mentions it.

*** New command 'ruby-find-library-file' bound to 'C-c C-f'.

** Package

*** Change of 'package-check-signature' for packages with multiple sigs
In previous Emacsen, 't' checked that all signatures are valid.
Now 't' only checks that at least one signature is valid and the new 'all'
value needs to be used if you want to enforce that all signatures
are valid.  This only affects packages with multiple signatures.

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

*** 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'.

** 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.

** 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.

+++
*** Changing 'xref-marker-ring-length' works after 'xref.el' is loaded.
Previously, setting 'xref-marker-ring-length' would only take effect
if set before 'xref.el' was loaded.

---
*** 'xref-find-definitions' now sets the mark at the buffer position
where it was invoked.

---
*** New xref faces 'xref-file-header', 'xref-line-number', 'xref-match'.

*** New variable 'xref-show-definitions-function'.
It encapsulates the logic pertinent to showing the result of
'xref-find-definitions'.  The user can change it to customize its
behavior and the display of results.

*** Search results show the buffer even for one hit.
The search-type Xref commands (e.g. 'xref-find-references' or
'project-find-regexp') now show the results buffer even when there is
only one hit.  This can be altered by changing
'xref-show-xrefs-function'.

*** Xref buffers support refreshing the search results.
A new command 'xref-revert-buffer' is bound to 'g'.

** Ecomplete

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

*** 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'.

** Gnus

---
*** Gnus now maps imaps to 993 only on old MS-Windows versions.
The nnimap backend used to do this unconditionally to work around
problems on old versions of MS-Windows.  This is now done only for
Windows XP and older.

+++
*** 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.

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

*** The function 'gnus-score-find-favorite-words' has been renamed
from 'gnus-score-find-favourite-words'.

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

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

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

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

---
*** New option 'nnir-notmuch-filter-group-names-function'.
This option controls whether and how to use Gnus search groups as
'path:' search terms to 'notmuch'.

** erc

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

** EUDC

*** XEmacs support has been removed.

** eww/shr

+++
*** The 'eww' command can now create a new EWW buffer.
Invoking the command with a prefix argument will cause it to create a
new EWW buffer for the URL instead of reusing the default one.

+++
*** The 'd' ('eww-download') command now falls back to current page's URL.
If this command is invoked with no URL at point, it now downloads the
current page instead of signaling an error.

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

+++
*** 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.

---
*** 'shr-tag-ol' now respects the ordered list 'start' attribute.

** 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'.

+++
** 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.

** Smtpmail

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

** Footnote mode

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

** 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'.

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