NEWS

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

Copyright (C) 2010-2014 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 24.

See files 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 24.5

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

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

** 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 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 '--enable-silent-rules' and the command
'make V=0' now do a better job of suppressing chatter.


* Startup Changes in Emacs 24.5


* Changes in Emacs 24.5

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

** New var `truncate-string-ellipsis' to choose how to indicate truncation.

---
** The default value of `history-length' has increased to 100.

+++
** 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 new functions `string-collate-lessp' and `string-collate-equalp'
preserve the collation order as defined by the system's locale(1)
environment.  For the time being this is implemented for modern POSIX
systems and for MS-Windows, for other systems they fall back to their
counterparts `string-lessp' and `string-equal'.

*** The ls-lisp package uses `string-collate-lessp' to sort file names.
If you want the old, locale-independent sorting, customize the new
option `ls-lisp-use-string-collate' to a nil value.

*** The MS-Windows specific variable `w32-collate-ignore-punctuation',
if set to a non-nil value, causes the above 2 functions to ignore
symbol and punctuation characters when collating strings.  This
emulates the behavior of modern Posix platforms when the locale's
codeset is "UTF-8" (as in "en_US.UTF-8").  This is needed because
MS-Windows doesn't support UTF-8 as codeset in its locales.


* Editing Changes in Emacs 24.5

** Emacs now supports "bracketed paste mode" when running on a terminal
that supports it.  This facility allows Emacs to understand pasted
chunks of text as strings to be inserted, instead of interpreting each
character in the pasted text as actual user input.  This results in a
paste experience similar to that under a window system, and significant
performance improvements when pasting large amounts of text.


* Changes in Specialized Modes and Packages in Emacs 24.5

** pcase
*** New UPatterns `quote' and `app'.
*** New UPatterns can be defined with `pcase-defmacro'.

** Lisp mode
*** Strings after `:documentation' are highlighted as docstrings.

** Rectangle editing
*** Rectangle Mark mode can have corners past EOL or in the middle of a TAB.
*** C-x C-x in rectangle-mark-mode now cycles through the four corners.
*** `string-rectangle' provides on-the-fly preview of the result.

+++
** Macro `pcase' now supports vector qpattern.

** New font-lock functions font-lock-ensure and font-lock-flush, which
should be used instead of font-lock-fontify-buffer when called from Elisp.

** Macro `minibuffer-with-setup-hook' takes (:append FUN) to mean
appending FUN to `minibuffer-setup-hook'.

** Calendar and diary

+++
*** New commands to insert diary entries with Chinese dates:
`diary-chinese-insert-anniversary-entry' `diary-chinese-insert-entry'
`diary-chinese-insert-monthly-entry', `diary-chinese-insert-yearly-entry'.

+++
*** Calendar can list and mark diary entries with Chinese dates.
See `diary-chinese-list-entries' and `diary-chinese-mark-entries'.

*** The mode line of the calendar buffer will not be modified if
`calendar-mode-line-format' is nil.

** New ERT function `ert-summarize-tests-batch-and-exit'.

---
** The Rmail commands d, C-d and u now handle repeat counts to delete or
undelete multiple messages.

** Rmail can now render HTML mail messages if your Emacs was built with
libxml2 or if you have the Lynx browser installed.  By default, Rmail
will display the HTML version of a mail message that has both HTML and
plain text parts, if display of HTML email is possible; customize the
`rmail-mime-prefer-html' option to `nil' if you don't want that.

** SES now supports local printer functions; see `ses-define-local-printer'.

** In sh-mode, you can now use `sh-shell' as a file-local variable to
specify the type of shell in use (bash, csh, etc).

** The URL package accepts now the protocols "ssh", "scp" and "rsync".
When `url-handler-mode' is enabled, file operations for these
protocols as well as for "telnet" and "ftp" are passed to Tramp.

** Tramp

*** New connection method "nc", which allows to access dumb busyboxes.

** SQL mode

*** New user variable `sql-default-directory' enables remote
connections using Tramp.

*** New command `sql-send-line-and-next' sends the current line to the
interactive buffer and advances to the next line, skipping whitespace
and comments.

*** Add support for Vertica SQL.

** VC and related modes

*** New option `vc-annotate-background-mode' controls whether
the color range from `vc-annotate-color-map' is applied to the
background or to the foreground.

** Calculator: decimal display mode uses "," groups, so it's more
fitting for use in money calculations; factorial works with
non-integer inputs.

** HideIfDef mode now support full C/C++ expressions, argumented macro expansions
, interactive macro evaluation and automatic scanning of #defined symbols.

*** New custom variable `hide-ifdef-header-regexp' to define C/C++ header file
name patterns. Default case-insensitive .h, .hh, .hpp and .hxx.
*** New custom variable `hide-ifdef-expand-reinclusion-protection' to prevent
reinclusion protected header files from being fully hidden.
*** New custom variable `hide-ifdef-exclude-define-regexp' to define symbol
name patterns (e.x. all "FOR_DOXYGEN_ONLY_*") to be excluded.

** TeX mode

*** New custom variable `tex-print-file-extension' to help users who
use PDF instead of DVI.

** Obsolete packages

---
*** gulp.el

---
*** crisp.el, tpu-edt.el, ws-mode.el
These emulations of old editors are believed to be no longer relevant
 - contact emacs-devel@gnu.org if you disagree.

---
*** vi.el, vip.el (try M-x viper instead)


* New Modes and Packages in Emacs 24.5


* Incompatible Lisp Changes in Emacs 24.5

** window-configurations no longer record the buffers's marks.

** inhibit-modification-hooks now also inhibits lock-file checks, as well as
active region handling.

** deactivate-mark is now buffer-local.

** `cl-the' now asserts that its argument is of the given type.

+++
** Mouse click events on mode line or header line no longer include
any reference to a buffer position.  The 6th member of the mouse
position list returned for such events is now nil.



* Lisp Changes in Emacs 24.5

*** call-process-shell-command and process-file-shell-command
don't take "&rest args" any more.

** New function `funcall-interactively', which works like `funcall'
but makes `called-interactively-p' treat the function as (you guessed it)
called interactively.

** New function `function-put' to use instead of `put' for function properties.

+++
** New properties that can be specified with `declare':
*** (interactive-only INSTEAD), says to use INSTEAD for non-interactive use.
*** (pure VAL), if VAL is non-nil, indicates the function is pure.
*** (side-effect-free VAL), if VAL is non-nil, indicates the function does not
have side effects.

+++
** New macro `with-file-modes', for evaluating expressions with default file
permissions set to temporary values (e.g., for creating private files).

** You can access the slots of structures using `cl-struct-slot-value'.

** Functions `rmail-delete-forward' and `rmail-delete-backward' take an
optional repeat-count argument.

** Function `sort' can deal with vectors.

---
** New utilities in subr-x.el:
*** New macros `if-let' and `when-let' allow defining bindings and to
    execute code depending whether all values are true.
*** New macros `thread-first' and `thread-last' allow threading a form
    as the first or last argument of subsequent forms.


* Changes in Frames and Windows Code in Emacs 24.5

** Emacs can now draw horizontal scroll bars on some platforms that
provide toolkit scroll bars, namely Gtk, Lucid, Motif and Windows.
Horizontal scroll bars are turned off by default.
*** New function `horizontal-scroll-bars-available-p' telling whether
    horizontal scroll bars are available on the underlying system.
*** New mode `horizontal-scroll-bar-mode' to toggle horizontal scroll
    bars on all existing and future frames.
*** New frame parameters `horizontal-scroll-bars' and
    `scroll-bar-height' to set horizontal scroll bars and their height
    for individual frames and in `default-frame-alist'.
*** New function `frame-scroll-bar-height' to return the height of
    horizontal scroll bars on a specific frame.
*** `set-window-scroll-bars' now accepts five parameters where the last
    two specify height and type of the window's horizontal scroll bar.

** The height of a frame's menu and tool bar are no more counted in the
frame's text height.  This means that the text height stands only for
the height of the frame's root window plus that of the echo area (if
present).  This was already the behavior for frames with external tool
and menu bars (like in the Gtk builds) but has now been extended to all
builds.

** Frames now do not necessarily preserve the number of columns or lines
they display when setting default font, menu bar, fringe width, or
scroll bars.  In particular, maximized and fullscreen frames are
conceptually never resized if such settings change.  For fullheight and
fullwidth frames, the behavior may depend on the toolkit used.
*** New option `frame-inhibit-implied-resize' if non-nil, means that
   setting default font, menu bar, fringe width, or scroll bars of a
   specific frame does not resize that frame in order to preserve the
   number of columns or lines it displays.

* Changes in Emacs 24.5 on Non-Free Operating Systems

---
** Building Emacs for MS-Windows requires at least Windows XP
or Windows Server 2003.  The built binaries still run on all versions
of Windows starting with Windows 9X.


* Installation Changes in Emacs 24.4

** Emacs can now be compiled with ACL (access control list) support.
This happens by default if a suitable support library is found at
build time, like libacl on GNU/Linux.  To prevent this, use the
configure option `--disable-acl'.  See below for the features this provides.

** Emacs can now be compiled with file notification support.
This happens by default if a suitable system library is found at
build time.  To prevent this, use the configure option
`--without-file-notification'.  See below for file-notify features.
This feature is not available for the Nextstep port.

** Emacs can now be compiled with zlib support.
This happens by default if zlib is present, which it normally is.
To prevent this, use the configure option `--without-zlib'.
This provides the function `zlib-decompress-region'; see below for details.

** The configure option `--without-compress-info' has been generalized,
and renamed to `--without-compress-install'.  It now prevents compression
of _any_ files during installation.

** The configure option `--with-crt-dir' has been removed.
It is no longer needed, as the crt*.o files are no longer linked specially.

** Directories passed to configure option `--enable-locallisppath' are
no longer created during installation.

** Emacs for Nextstep (Mac OS X, GNUstep) can be built with ImageMagick support.
This requires pkg-config to be available at build time.


* Startup Changes in Emacs 24.4

** When initializing `load-path', an empty element in the EMACSLOADPATH
environment variable (either leading, e.g., ":/foo"; trailing, e.g.,
"/foo:"; or embedded, e.g., "/foo::/bar") is replaced with the default
load-path (the one that would have been used if EMACSLOADPATH was unset).
This makes it easier to _extend_ the load-path via EMACSLOADPATH
(previously, EMACSLOADPATH had to specify the complete load-path,
including the defaults).  (In older versions of Emacs, an empty element
was replaced by ".", so use an explicit "." now if that is what you want.)

** The -L option, which normally prepends its argument to load-path,
will instead append, if the argument begins with `:' (or `;' on MS Windows;
i.e., `path-separator').

** If you use either site-load.el or site-init.el to customize the dumped
Emacs executable, any changes to `load-path' that these files make
will no longer be present after dumping.  To affect a permanent change
to `load-path', use the `--enable-locallisppath' option of `configure'.

** The user option `initial-buffer-choice' can now specify a function
to set up the initial buffer.


* Changes in Emacs 24.4

** Support for ACLs (access control lists).
This requires a suitable support library to be found at build time.
On GNU/Linux, the POSIX ACL interface is used via libacl.
On MS-Windows, the NT Security APIs are used to emulate the POSIX interface.
ACLs are extended file attributes, used e.g. for finer-grained permissions.

*** Emacs preserves the ACL entries of files when backing up.

*** New functions `file-acl' and `set-file-acl' get and set file ACLs.

** Support for menus on text-mode terminals.
If the terminal supports a mouse, clicking on the menu bar, or on
sensitive portions of the mode line or header line, will drop down the
menu defined at that position.  Likewise, clicking C-mouse-1, C-mouse-2, or
C-mouse-3 on the text area will pop up the menus defined for those locations.

If the text terminal does not support a mouse, you can activate the
first menu-bar menu by typing F10, which invokes `menu-bar-open'.

If you want the previous behavior, where F10 invoked `tmm-menubar',
customize the option `tty-menu-open-use-tmm' to a non-nil value.
(Typing M-` always invokes `tmm-menubar', even if `tty-menu-open-use-tmm'
is nil.)

** New option `load-prefer-newer' affects how the `load' function chooses
the file to load.  If this is non-nil, then when both .el and .elc
versions of a file exist, and the caller did not explicitly specify
which one to load, then the newer file is loaded.  The default, nil,
means to always load the .elc file.

** Multi-monitor support

*** New functions `display-monitor-attributes-list' and
`frame-monitor-attributes' can be used to obtain information about
each physical monitor on multi-monitor setups.

*** The functions `display-pixel-width' and `display-pixel-height' now
behave consistently among the platforms: they return the pixel width
or height for all physical monitors associated with the given display
as if they were on X.  To get information for each physical
monitor, use the new functions above.  Similar notes also apply to
`x-display-pixel-width', `x-display-pixel-height', `display-mm-width',
`display-mm-height', `x-display-mm-width', and `x-display-mm-height'.

** New function `zlib-decompress-region', which decompresses gzip- and
zlib-format compressed data using built-in zlib support (if available).

** The *Messages* buffer is created in `messages-buffer-mode',
a new major mode, with read-only status.  Any code that might create
the *Messages* buffer should call the function `messages-buffer' to do
so and set up the mode.

** The cursor stops blinking after 10 blinks (by default) on X and Nextstep.
You can change the default by customizing `blink-cursor-blinks'.

** In keymaps where SPC scrolls forward, S-SPC now scrolls backward.
This affects View mode, etc.

** The default value of `make-backup-file-name-function' is no longer nil.
Instead it defaults to a function that does what the nil value used to.

** Help

*** The command `apropos-variable' is renamed to `apropos-user-option'.
`apropos-user-option' shows all user options, while `apropos-variable'
shows all variables.  When called with a universal prefix argument,
the two commands swap their behaviors.  When `apropos-do-all' is
non-nil, they output the same results.

*** The key `?' now describes prefix bindings, like `C-h'.

*** The command `describe-function' has been extended for EIEIO.
Running it on constructors will show a full description of the
generated class.  For generic functions, it will show all
implementations together with links to the source.  The old commands
`describe-class', `describe-constructor' and `describe-generic' were
removed.

*** The function `quail-help' is no longer an interactive command.
Use `C-h C-\' (`describe-input-method') instead.

** Frame and window handling

*** New commands `toggle-frame-fullscreen' and `toggle-frame-maximized',
bound to <f11> and M-<f10>, respectively.

*** New hooks `focus-in-hook', `focus-out-hook'.
These are normal hooks run when an Emacs frame gains or loses input focus.

*** The function `window-in-direction' now takes additional arguments
for specifying a reference point, wrapping the selection around frame
borders, and specifying ways to select the minibuffer window.

*** Emacs can now change frame sizes in units of pixels, rather than
text rows or columns.  When maximizing a frame or making it fullscreen,
remaining extra pixels are no longer given to the minibuffer, the rightmost
fringe, or other unusable space, but are distributed among the text
areas of the frame's windows.  If the new option `frame-resize-pixelwise'
is non-nil, all frame size changes happen pixelwise and set the
corresponding size hints for the window manager.

*** Emacs can now change window sizes in units of pixels.
Mouse-dragging a mode line or window divider now changes the size of
adjacent windows pixelwise.  If the new option `window-resize-pixelwise'
is non-nil, functions like `balance-windows-area' and `fit-window-to-buffer'
resize windows pixelwise.  Most functions for changing or accessing
window sizes now have an additional argument that allows changes to apply,
or values to be returned, in pixels instead of lines/columns.

*** The functions `window-body-height' and `window-body-width' now never
count partially visible lines or columns if called with a nil PIXELWISE
argument.

*** Emacs can now draw dividers between adjacent windows.  To put
dividers between side-by-side/vertically stacked windows customize the
frame parameters `right-divider-width' and `bottom-divider-width' to
some positive integer.  You can drag dividers with the mouse (they show
a corresponding cursor when the mouse hovers over them).  You can change
the appearance of dividers by customizing the faces `window-divider',
`window-divider-first-pixel', and `window-divider-last-pixel'.  The last
two are useful to provide a 3D effect, or to better distinguish dividers
from surrounding display objects.

*** New functions to return the pixel sizes of window components, namely
`window-scroll-bar-width', `window-mode-line-height',
`window-header-line-height', `window-right-divider-width', and
`window-bottom-divider-width'.

*** The new function `window-text-pixel-size' returns the size of the
text of a window's buffer in pixels.  This allows functions like
`fit-frame-to-buffer' and `fit-window-to-buffer' to accurately fit a
window to its buffer as it will be displayed.

*** `fit-window-to-buffer' can now resize windows in both dimensions.
This behavior is controlled by the new option
`fit-window-to-buffer-horizontally'.  The new option
`fit-frame-to-buffer' allows you to fit the window's frame to its buffer.

*** `fit-frame-to-buffer' now fits frames in both dimensions.  The new
options `fit-frame-to-buffer-margins' and `fit-frame-to-buffer-sizes'
control the size of the frame and its position on screen.

*** Temp Buffer Resize Mode can now adjust the height and width of
windows and frames.  The new option `temp-buffer-max-width' allows you to
control the width of temporary buffer windows.  Moreover, if the new
option `fit-frame-to-buffer' is non-nil and the buffer appears in the
root window of a frame, Temp Buffer Resize Mode will try to adjust the
width and/or height of the frame.

*** `split-window' is now a non-interactive function, not a command.
As a command, it was a special case of `C-x 2' (`split-window-below'),
and as such superfluous.  After being reimplemented in Lisp, its
interactive form was mistakenly retained.

*** The functions `window-size' and `window-total-size' now have an
optional argument to return a rounded size value.

*** `window-state-put' now allows you to put a window state into internal
windows too.

*** New option `scroll-bar-adjust-thumb-portion'.
Available only on X, this option allows you to control over-scrolling
using the scroll bar (i.e., dragging the thumb down even when the end
of the buffer is visible).

*** New display actions functions for `display-buffer':

**** `display-buffer-at-bottom' chooses or creates a window at the
bottom of the selected frame.

**** `display-buffer-no-window' to not display the buffer in a window.

*** New display action alist entry `allow-no-window' to indicate the
caller of `display-buffer' is ready to handle the case of not displaying
the buffer in a window.

*** `display-buffer-in-previous-window' is now a member of
`display-buffer-fallback-action'.

** Lisp evaluation

*** `eval-defun' on an already defined defcustom calls the :set function,
if there is one.

*** The commands `eval-expression' (`M-:'), `eval-last-sexp' (`C-x C-e'),
and `eval-print-last-sexp' (`C-j' in Lisp Interaction mode) can take a
zero prefix argument.  This disables truncation of lists in the output,
equivalent to setting `(eval-expression-)print-length' and
`(eval-expression-)print-level' to nil.  Additionally, it causes integers
to be printed in other formats (octal, hexadecimal, and character).

*** New hook `eval-expression-minibuffer-setup-hook' run by
`eval-expression' on entering the minibuffer.

** `cache-long-line-scans' is now non-nil, and renamed to `cache-long-scans',
because it affects caching of paragraph scanning results as well.
There is no reason to set this to nil except for debugging purposes.

** `emacs-bzr-version' has been renamed to `emacs-repository-version',
and works for git too, if you fetch the repository notes.

** The default value of `comment-use-global-state' is now t,
and this variable has been marked obsolete.

** `write-region-inhibit-fsync' now defaults to t in batch mode.

** The option `set-mark-default-inactive' has been deleted.
This unfinished feature was introduced by accident in Emacs 23.1;
simply disabling Transient Mark mode does the same thing.


* Editing Changes in Emacs 24.4

** Indentation

*** `electric-indent-mode' is now enabled by default.
Typing RET reindents the current line and indents the new line.
`C-j' inserts a newline but does not indent.  In some programming modes,
additional characters are electric (eg `{').

*** New buffer-local `electric-indent-local-mode'.

*** The behavior of `C-x TAB' (`indent-rigidly') has changed.
When invoked without a prefix argument, it now activates a transient
mode in which typing <left>, <right>, <S-left>, and <S-right> adjusts
the text indentation in the region.  Typing any other key resumes
normal editing behavior.

*** `tab-stop-list' is now implicitly extended to infinity by repeating
the last step.  Its default value is changed to nil, which means a tab
stop every `tab-width' columns.

** Uniquify is enabled by default, with `post-forward-angle-brackets' style.
In other words, if you visit two files that have the same base name,
then rather than creating buffers basename and basename<2>,
Emacs uses basename<dirA> and basename<dirB>.  To change this,
customize `uniquify-buffer-name-style'.  Set it to nil for the old behavior.

** New command `C-x SPC' (`rectangle-mark-mode') makes a rectangular region.
Most commands are still unaware of it, but kill/yank do work on the rectangle.

** New option `visual-order-cursor-movement'.
If this is non-nil, cursor motion with arrow keys will follow the
visual order of characters on the screen: <left> always moves to the
left, <right> always moves to the right, disregarding the surrounding
bidirectional context.

** New command `delete-duplicate-lines'.
This searches the region for identical lines, and removes all but one
copy of each repeated line.  The lines need not be sorted.

** New command `cycle-spacing' acts like a smarter `just-one-space'.
When called in succession, it cycles between spacing conventions:
one space, no spaces, original spacing.

** `blink-matching-paren' now only highlights the matching open-paren
by default, instead of moving the cursor.  Set this variable to `jump' to
restore the old behavior.

** The new function `fill-single-char-nobreak-p' can stop fill from breaking
a line after a one-letter word, which is an error in some typographical
conventions.  To use it, add it to the `fill-nobreak-predicate' hook.

** Registers

*** All interactive commands that read a register (`copy-to-register', etc.)
now display a temporary window after `register-preview-delay' seconds
that summarizes existing registers.  To disable this, set that option to nil.
Interactive commands that read registers and want to make use of this
should use `register-read-with-preview' to read register names.

*** New command `frameset-to-register' bound to `C-x r f', replacing
`frame-configuration-to-register'.  It offers similar functionality,
plus enhancements like the ability to restore deleted frames.
(`frame-configuration-to-register' still exists, but no longer has a
key binding.)

*** New command `C-x C-k x' (`kmacro-to-register') stores keyboard
macros in registers.


* Changes in Specialized Modes and Packages in Emacs 24.4

** Backtrace and debugger

*** New Lisp debugger command `v' (`debugger-toggle-locals') toggles the
display of local variables of the current stack frame.

*** The Lisp debugger's `e' command (`debugger-eval-expression') now includes
the lexical environment when evaluating the code in the context at point
(and so allows you to access lexical variables).

*** New minor mode `jit-lock-debug-mode' helps you debug code run via JIT Lock.

** Battery information can now be retrieved from BSD's `apm' utility.

** In the Buffer Menu, `M-s a C-o' shows matches for a regexp in marked buffers.

** Calc

*** Calc by default now uses the Gregorian calendar for all dates, and
uses January 1, 1 AD as its day number 1.  Previously Calc used the
Julian calendar for dates before September 14, 1752, and it used
December 31, 1 BC as its day number 1; the new scheme is more
consistent with Calendar's calendrical system and day numbering.

*** The new option `calc-gregorian-switch' lets you configure if
(and when) Calc switches from the Julian to the Gregorian calendar.

*** Support for ISO 8601 dates.

** Calendar and Diary

*** New faces `calendar-weekday-header', `calendar-weekend-header',
and `calendar-month-header'.

*** New option `calendar-day-header-array'.

*** New variable `diary-from-outlook-function', used by the command
`diary-from-outlook'.

*** The variable `calendar-font-lock-keywords' is obsolete.

** CEDET

*** EDE

**** The cpp-root project now supports executing a compile command.
It can be set through the new :compile-command slot or the
buffer-local variable `compile-command'.

**** Better selection of include directories for the 'linux' project.
Include directories now support out-of-tree build directories and
target architecture auto-detection.

*** Semantic

**** Improved detection of used namespaces in current scope in C++.

**** Parsing of default values for variables and function arguments in C/C++.
They are also displayed by the summarize feature in the mode line.

**** Improved parsing of function pointers in C/C++.
This also includes parsing of function pointers as function arguments.

**** Parsing of C/C++ preprocessor macros that open new scope.
For example, this enables parsing of macros that open new namespaces.

**** Support for 'this' pointer in inline member functions in C++.

** CFEngine mode

*** Support for completion, ElDoc, and Flycheck has been added.

*** The current CFEngine syntax is parsed from "cf-promises -s json".
There is a fallback syntax available if you don't have cf-promises or
if your version doesn't support that option.  See option `cfengine-cf-promises'.

** cl-lib

*** New macro `cl-tagbody'.
This executes statements while allowing for control transfer to labels.

*** letf is now just an alias for cl-letf.

** CUA mode

*** CUA mode now uses `delete-selection-mode' and `shift-select-mode'.
Hence, you can now enable it independently from those modes, and from
`transient-mark-mode'.

*** `cua-highlight-region-shift-only' is now obsolete.
You can disable `transient-mark-mode' to get the same result.

*** CUA's rectangles can now be used without CUA by calling the command
`cua-rectangle-mark-mode'.

** Delete Selection mode can now be used without Transient Mark mode.

** Desktop

*** `desktop-save-mode' by default now auto-saves an existing desktop file
after `desktop-auto-save-timeout'.  To disable this, customize that option
to nil (or zero).

*** Desktop now saves and restores the frame/window configuration.
To disable this, set `desktop-restore-frames' to nil.
See also related options `desktop-restore-reuses-frames',
`desktop-restore-in-current-display', and `desktop-restore-forces-onscreen'.

** New Dired minor mode `dired-hide-details-mode' toggles whether details,
such as file ownership or permissions, are visible in Dired buffers.
See the new options `dired-hide-details-hide-symlink-targets' and
`dired-hide-details-hide-information-lines' for customizing what to hide.

** You can enable ElDoc inside the `eval-expression' minibuffer with:
  (add-hook 'eval-expression-minibuffer-setup-hook 'eldoc-mode)
The results display in the mode line.

** Electric Pair mode

*** New option `electric-pair-preserve-balance', enabled by default.
If non-nil, pairing/skipping only kicks in when that help the balance
of parentheses and quotes; i.e., the buffer should end up at least as
balanced as before.

You can further control this behavior by adjusting the predicates
stored in `electric-pair-inhibit-predicate' and `electric-pair-skip-self'.

*** New option `electric-pair-delete-adjacent-pairs', enabled by default.
In `electric-pair-mode', the commands `backward-delete-char' and
`backward-delete-char-untabify' are now bound to electric variants
that delete the closer when invoked between adjacent pairs.

*** New option `electric-pair-open-newline-between-pairs', enabled by default.
In `electric-pair-mode', inserting a newline between adjacent pairs
opens an extra newline after point, which is indented if
`electric-indent-mode' is also set.

*** New option `electric-pair-skip-whitespace', enabled by default.
This controls if skipping over closing delimiters should jump over any
whitespace slack.  Setting it to `chomp' makes it delete this
whitespace.  See also the variable `electric-pair-skip-whitespace-chars'.

*** New variables control the pairing in strings and comments.
You can customize `electric-pair-text-pairs' and
`electric-pair-text-syntax-table' to tweak pairing behavior inside
strings and comments.

** New EPA option `epa-mail-aliases'.
You can set this to a list of email address aliases that `epa-mail-encrypt'
should use to find keys.

** New ERC option `erc-accidental-paste-threshold-seconds'.
If set to a number, this can be used to avoid accidentally pasting large
amounts of data into the ERC input.

** New ERT macro `skip-unless' allows skipping ERT tests.

** Eshell

*** `eshell' now supports visual subcommands and options.
Eshell has been able to handle "visual" commands (interactive,
non-line oriented commands such as top that require display
capabilities not provided by eshell) by running them in an Emacs
terminal emulator.  See `eshell-visual-commands'.

This feature has been extended to subcommands and options that make a
usually line-oriented command a visual command.  Typical examples are
"git log" and "git <command> --help", which display their output in a
pager by default.  See `eshell-visual-subcommands' and `eshell-visual-options'.

*** New Eshell-Tramp module.
External su and sudo commands are now the default; the internal,
Tramp-using variants can still be used by enabling the eshell-tramp module.

** New F90 mode option `f90-smart-end-names'.

** New option `gnutls-verify-error', if non-nil, means that Emacs
should reject SSL/TLS certificates that GnuTLS determines as invalid.
(This option defaults to nil at present, but this is expected to change
in a future release.)

** Hi-Lock

*** New global command `M-s h .' (`highlight-symbol-at-point') highlights
the symbol near point.

*** New option `hi-lock-auto-select-face'.  When non-nil, hi-lock commands
will cycle through faces in `hi-lock-face-defaults' without prompting.

** Icomplete is now more similar to Ido.

*** Icomplete by default now applies to all forms of minibuffer completion.
The variable `icomplete-with-completion-tables' (now a user option)
controls this.  To restore the old behavior, set it back to
'(internal-complete-buffer).

*** You can navigate through and select completions using the keys
from `icomplete-minibuffer-map'.

*** The string that separates potential completions is now a customizable
option (`icomplete-separator').  The default is " | " rather than ",".

*** New face `icomplete-first-match'; and new options
`icomplete-hide-common-prefix' and `icomplete-show-matches-on-no-input'.

*** The option `icomplete-show-key-bindings' has been removed.

** Ido

*** An Ido user manual is now included.

*** The option `ido-use-virtual-buffers' can now take the value `auto'.
This means to use virtual buffers if the current ido input does not match
an existing buffer.

*** The variable `ido-decorations' can optionally have two new elements,
which are the brackets to use around the sole remaining completion.

** Image mode

*** New commands `n' (`image-next-file') and `p' (`image-previous-file')
visit the next image file and the previous image file in the same
directory, respectively.

*** New commands to show specific frames of multi-frame images.
`f' (`image-next-frame') and `b' (`image-previous-frame') visit the
next or previous frame.  `F' (`image-goto-frame') shows a specific frame.

*** New commands to speed up, slow down, or reverse animation.
`a +' (`image-increase-speed') and `a -' (`image-decrease-speed') to
speed up and slow down the animation.  `a r' (`image-reverse-speed')
to reverse it and `a 0' (`image-reset-speed') to reset it.

*** The command `image-mode-fit-frame' deletes other windows.
When toggling, it restores the frame's previous window configuration.
It also has an optional frame argument, which can be used by Lisp
callers to fit the image to a frame other than the selected frame.