GNU Emacs NEWS -- history of user-visible changes. 2006-05-31

Copyright (C) 2000-2023 Free Software Foundation, Inc.

See the end of the file for license conditions.

This file is about changes in Emacs version 21.



* Emacs 21.4 is a bug-fix release with no user-visible changes.



* Installation changes in Emacs 21.3

** Support for GNU/Linux on little-endian MIPS and on IBM S390 has

been added.



* Changes in Emacs 21.3

** The obsolete C mode (c-mode.el) has been removed to avoid problems

with Custom.

** UTF-16 coding systems are available, encoding the same characters

as mule-utf-8.

** There is a new language environment for UTF-8 (set up automatically

in UTF-8 locales).

** Translation tables are available between equivalent characters in

different Emacs charsets -- for instance `e with acute' coming from the

Latin-1 and Latin-2 charsets. User options 'unify-8859-on-encoding-mode'

and 'unify-8859-on-decoding-mode' respectively turn on translation

between ISO 8859 character sets ('unification') on encoding

(e.g. writing a file) and decoding (e.g. reading a file). Note that

'unify-8859-on-encoding-mode' is useful and safe, but

'unify-8859-on-decoding-mode' can cause text to change when you read

it and write it out again without edits, so it is not generally advisable.

By default 'unify-8859-on-encoding-mode' is turned on.

** In Emacs running on the X window system, the default value of

'selection-coding-system' is now 'compound-text-with-extensions'.

If you want the old behavior, set selection-coding-system to

compound-text, which may be significantly more efficient. Using

compound-text-with-extensions seems to be necessary only for decoding

text from applications under XFree86 4.2, whose behavior is actually

contrary to the compound text specification.



* Installation changes in Emacs 21.2

** Support for BSD/OS 5.0 has been added.

** Support for AIX 5.1 was added.



* Changes in Emacs 21.2

** Emacs now supports compound-text extended segments in X selections.

X applications can use `extended segments' to encode characters in

compound text that belong to character sets which are not part of the

list of approved standard encodings for X, e.g. Big5. To paste

selections with such characters into Emacs, use the new coding system

'compound-text-with-extensions' as the value of 'selection-coding-system'.

** The default values of 'tooltip-delay' and 'tooltip-hide-delay'

were changed.

** On terminals whose erase-char is ^H (Backspace), Emacs

now uses 'normal-erase-is-backspace-mode'.

** When the *scratch* buffer is recreated, its mode is set from

'initial-major-mode', which normally is 'lisp-interaction-mode',

instead of using 'default-major-mode'.

** The new option 'Info-scroll-prefer-subnodes' causes Info to behave

like the stand-alone Info reader (from the GNU Texinfo package) as far

as motion between nodes and their subnodes is concerned. If it is t

(the default), Emacs behaves as before when you type SPC in a menu: it

visits the subnode pointed to by the first menu entry. If this option

is nil, SPC scrolls to the end of the current node, and only then goes

to the first menu item, like the stand-alone reader does.

This change was already in Emacs 21.1, but wasn't advertised in the

NEWS.



* Lisp Changes in Emacs 21.2

** The meanings of 'scroll-up-aggressively' and 'scroll-down-aggressively'

have been interchanged, so that the former now controls scrolling up,

and the latter now controls scrolling down.

** The variable 'compilation-parse-errors-filename-function' can

be used to transform filenames found in compilation output.



* Installation Changes in Emacs 21.1

See the INSTALL file for information on installing extra libraries and

fonts to take advantage of the new graphical features and extra

charsets in this release.

** Support for GNU/Linux on IA64 machines has been added.

** Support for LynxOS has been added.

** There are new configure options associated with the support for

images and toolkit scrollbars. Use the --help option in 'configure'

to list them.

** You can build a 64-bit Emacs for SPARC/Solaris systems which

support 64-bit executables and also on Irix 6.5. This increases the

maximum buffer size. See etc/MACHINES for instructions. Changes to

build on other 64-bit systems should be straightforward modulo any

necessary changes to unexec.

** There is a new configure option '--disable-largefile' to omit

Unix-98-style support for large files if that is available.

** There is a new configure option '--without-xim' that instructs

Emacs to not use X Input Methods (XIM), if these are available.

** 'movemail' defaults to supporting POP. You can turn this off using

the --without-pop configure option, should that be necessary.

** This version can be built for the Macintosh, but does not implement

all of the new display features described below. The port currently

lacks unexec, asynchronous processes, and networking support. See the

"Emacs and the Mac OS" appendix in the Emacs manual, for the

description of aspects specific to the Mac.

** Note that the MS-Windows port does not yet implement various of the

new display features described below.



* Changes in Emacs 21.1

** Emacs has a new redisplay engine.

The new redisplay handles characters of variable width and height.

Italic text can be used without redisplay problems. Fonts containing

oversized characters, i.e. characters larger than the logical height

of a font can be used. Images of various formats can be displayed in

the text.

** Emacs has a new face implementation.

The new faces no longer fundamentally use X font names to specify the

font. Instead, each face has several independent attributes--family,

height, width, weight and slant--that it may or may not specify.

These attributes can be merged from various faces, and then together

specify a font.

Faces are supported on terminals that can display color or fonts.

These terminal capabilities are auto-detected. Details can be found

under Lisp changes, below.

** Emacs can display faces on TTY frames.

Emacs automatically detects terminals that are able to display colors.

Faces with a weight greater than normal are displayed extra-bright, if

the terminal supports it. Faces with a weight less than normal and

italic faces are displayed dimmed, if the terminal supports it.

Underlined faces are displayed underlined if possible. Other face

attributes such as 'overline', 'strike-through', and 'box' are ignored

on terminals.

The command-line options `-fg COLOR', `-bg COLOR', and '-rv' are now

supported on character terminals.

Emacs automatically remaps all X-style color specifications to one of

the colors supported by the terminal. This means you could have the

same color customizations that work both on a windowed display and on

a TTY or when Emacs is invoked with the -nw option.

** New default font is Courier 12pt under X.

** Sound support

Emacs supports playing sound files on GNU/Linux and FreeBSD (Voxware

driver and native BSD driver, a.k.a. Luigi's driver). Currently

supported file formats are RIFF-WAVE (*.wav) and Sun Audio (*.au).

You must configure Emacs with the option '--with-sound=yes' to enable

sound support.

** Emacs now resizes mini-windows if appropriate.

If a message is longer than one line, or minibuffer contents are

longer than one line, Emacs can resize the minibuffer window unless it

is on a frame of its own. You can control resizing and the maximum

minibuffer window size by setting the following variables:

- User option: 'max-mini-window-height'

Maximum height for resizing mini-windows. If a float, it specifies a

fraction of the mini-window frame's height. If an integer, it

specifies a number of lines.

Default is 0.25.

- User option: 'resize-mini-windows'

How to resize mini-windows. If nil, don't resize. If t, always

resize to fit the size of the text. If 'grow-only', let mini-windows

grow only, until they become empty, at which point they are shrunk

again.

Default is 'grow-only'.

** LessTif support.

Emacs now runs with the LessTif toolkit (see

<https://lesstif.sourceforge.net>). You will need version 0.92.26, or later.

** LessTif/Motif file selection dialog.

When Emacs is configured to use LessTif or Motif, reading a file name

from a menu will pop up a file selection dialog if 'use-dialog-box' is

non-nil.

** File selection dialog on MS-Windows is supported.

When a file is visited by clicking File->Open, the MS-Windows version

now pops up a standard file selection dialog where you can select a

file to visit. File->Save As also pops up that dialog.

** Toolkit scroll bars.

Emacs now uses toolkit scroll bars if available. When configured for

LessTif/Motif, it will use that toolkit's scroll bar. Otherwise, when

configured for Lucid and Athena widgets, it will use the Xaw3d scroll

bar if Xaw3d is available. You can turn off the use of toolkit scroll

bars by specifying '--with-toolkit-scroll-bars=no' when configuring

Emacs.

When you encounter problems with the Xaw3d scroll bar, watch out how

Xaw3d is compiled on your system. If the Makefile generated from

Xaw3d's Imakefile contains a '-DNARROWPROTO' compiler option, and your

Emacs system configuration file `s/your-system.h' does not contain a

define for NARROWPROTO, you might consider adding it. Take

`s/freebsd.h' as an example.

Alternatively, if you don't have access to the Xaw3d source code, take

a look at your system's imake configuration file, for example in the

directory `/usr/X11R6/lib/X11/config' (paths are different on

different systems). You will find files `*.cf' there. If your

system's cf-file contains a line like `#define NeedWidePrototypes NO',

add a `#define NARROWPROTO' to your Emacs system configuration file.

The reason for this is that one Xaw3d function uses 'double' or

'float' function parameters depending on the setting of NARROWPROTO.

This is not a problem when Imakefiles are used because each system's

imake configuration file contains the necessary information. Since

Emacs doesn't use imake, this has do be done manually.

** Tool bar support.

Emacs supports a tool bar at the top of a frame under X. For details

of how to define a tool bar, see the page describing Lisp-level

changes. Tool-bar global minor mode controls whether or not it is

displayed and is on by default. The appearance of the bar is improved

if Emacs has been built with XPM image support. Otherwise monochrome

icons will be used.

To make the tool bar more useful, we need contributions of extra icons

for specific modes (with copyright assignments).

** Tooltips.

Tooltips are small X windows displaying a help string at the current

mouse position. The Lisp package 'tooltip' implements them. You can

turn them off via the user option 'tooltip-mode'.

Tooltips also provides support for GUD debugging. If activated,

variable values can be displayed in tooltips by pointing at them with

the mouse in source buffers. You can customize various aspects of the

tooltip display in the group 'tooltip'.

** Automatic Hscrolling

Horizontal scrolling now happens automatically if

'automatic-hscrolling' is set (the default). This setting can be

customized.

If a window is scrolled horizontally with 'set-window-hscroll', or

'scroll-left'/'scroll-right' (C-x <, C-x >), this serves as a lower bound

for automatic horizontal scrolling. Automatic scrolling will scroll

the text more to the left if necessary, but won't scroll the text more

to the right than the column set with set-window-hscroll etc.

** When using a windowing terminal, each Emacs window now has a cursor

of its own. By default, when a window is selected, the cursor is

solid; otherwise, it is hollow. The user-option

'cursor-in-non-selected-windows' controls how to display the

cursor in non-selected windows. If nil, no cursor is shown, if

non-nil a hollow box cursor is shown.

** Fringes to the left and right of windows are used to display

truncation marks, continuation marks, overlay arrows and alike. The

foreground, background, and stipple of these areas can be changed by

customizing face 'fringe'.

** The mode line under X is now drawn with shadows by default.

You can change its appearance by modifying the face 'mode-line'.

In particular, setting the `:box' attribute to nil turns off the 3D

appearance of the mode line. (The 3D appearance makes the mode line

occupy more space, and thus might cause the first or the last line of

the window to be partially obscured.)

The variable 'mode-line-inverse-video', which was used in older

versions of emacs to make the mode-line stand out, is now deprecated.

However, setting it to nil will cause the 'mode-line' face to be

ignored, and mode-lines to be drawn using the default text face.

** Mouse-sensitive mode line.

Different parts of the mode line have been made mouse-sensitive on all

systems which support the mouse. Moving the mouse to a

mouse-sensitive part in the mode line changes the appearance of the

mouse pointer to an arrow, and help about available mouse actions is

displayed either in the echo area, or in the tooltip window if you

have enabled one.

Currently, the following actions have been defined:

- Mouse-1 on the buffer name in the mode line goes to the next buffer.

- Mouse-3 on the buffer-name goes to the previous buffer.

- Mouse-2 on the read-only or modified status in the mode line (`%' or

`*') toggles the status.

- Mouse-3 on the major mode name displays a major mode menu.

- Mouse-3 on the mode name displays a minor-mode menu.

** Hourglass pointer

Emacs can optionally display an hourglass pointer under X. You can

turn the display on or off by customizing group 'cursor'.

** Blinking cursor

M-x blink-cursor-mode toggles a blinking cursor under X and on

terminals having terminal capabilities 'vi', 'vs', and 've'. Blinking

and related parameters like frequency and delay can be customized in

the group 'cursor'.

** New font-lock support mode 'jit-lock-mode'.

This support mode is roughly equivalent to 'lazy-lock' but is

generally faster. It supports stealth and deferred fontification.

See the documentation of the function 'jit-lock-mode' for more

details.

Font-lock uses jit-lock-mode as default support mode, so you don't

have to do anything to activate it.

** The default binding of the Delete key has changed.

The new user-option 'normal-erase-is-backspace' can be set to

determine the effect of the Delete and Backspace function keys.

On window systems, the default value of this option is chosen

according to the keyboard used. If the keyboard has both a Backspace

key and a Delete key, and both are mapped to their usual meanings, the

option's default value is set to t, so that Backspace can be used to

delete backward, and Delete can be used to delete forward. On

keyboards which either have only one key (usually labeled DEL), or two

keys DEL and BS which produce the same effect, the option's value is

set to nil, and these keys delete backward.

If not running under a window system, setting this option accomplishes

a similar effect by mapping C-h, which is usually generated by the

Backspace key, to DEL, and by mapping DEL to C-d via

'keyboard-translate'. The former functionality of C-h is available on

the F1 key. You should probably not use this setting on a text-only

terminal if you don't have both Backspace, Delete and F1 keys.

Programmatically, you can call function 'normal-erase-is-backspace-mode'

to toggle the behavior of the Delete and Backspace keys.

** The default for user-option 'next-line-add-newlines' has been

changed to nil, i.e. C-n will no longer add newlines at the end of a

buffer by default.

** The <home> and <end> keys now move to the beginning or end of the

current line, respectively. C-<home> and C-<end> move to the

beginning and end of the buffer.

** Emacs now checks for recursive loads of Lisp files. If the

recursion depth exceeds 'recursive-load-depth-limit', an error is

signaled.

** When an error is signaled during the loading of the user's init

file, Emacs now pops up the *Messages* buffer.

** Emacs now refuses to load compiled Lisp files which weren't

compiled with Emacs. Set 'load-dangerous-libraries' to t to change

this behavior.

The reason for this change is an incompatible change in XEmacs's byte

compiler. Files compiled with XEmacs can contain byte codes that let

Emacs dump core.

** Toggle buttons and radio buttons in menus.

When compiled with LessTif (or Motif) support, Emacs uses toolkit

widgets for radio and toggle buttons in menus. When configured for

Lucid, Emacs draws radio buttons and toggle buttons similar to Motif.

** The menu bar configuration has changed. The new configuration is

more CUA-compliant. The most significant change is that Options is

now a separate menu-bar item, with Mule and Customize as its submenus.

** Item Save Options on the Options menu allows saving options set

using that menu.

** Highlighting of trailing whitespace.

When 'show-trailing-whitespace' is non-nil, Emacs displays trailing

whitespace in the face 'trailing-whitespace'. Trailing whitespace is

defined as spaces or tabs at the end of a line. To avoid busy

highlighting when entering new text, trailing whitespace is not

displayed if point is at the end of the line containing the

whitespace.

** C-x 5 1 runs the new command 'delete-other-frames' which deletes

all frames except the selected one.

** The new user-option 'confirm-kill-emacs' can be customized to

let Emacs ask for confirmation before exiting.

** The header line in an Info buffer is now displayed as an emacs

header-line (which is like a mode-line, but at the top of the window),

so that it remains visible even when the buffer has been scrolled.

This behavior may be disabled by customizing the option

'Info-use-header-line'.

** Polish, Czech, German, and French translations of Emacs' reference card

have been added. They are named `pl-refcard.tex', `cs-refcard.tex',

`de-refcard.tex' and `fr-refcard.tex'. PostScript files are included.

** An `Emacs Survival Guide', etc/survival.tex, is available.

** A reference card for Dired has been added. Its name is

`dired-ref.tex'. A French translation is available in

`fr-drdref.tex'.

** C-down-mouse-3 is bound differently. Now if the menu bar is not

displayed it pops up a menu containing the items which would be on the

menu bar. If the menu bar is displayed, it pops up the major mode

menu or the Edit menu if there is no major mode menu.

** Variable 'load-path' is no longer customizable through Customize.

You can no longer use `M-x customize-variable' to customize 'load-path'

because it now contains a version-dependent component. You can still

use 'add-to-list' and 'setq' to customize this variable in your

`~/.emacs' init file or to modify it from any Lisp program in general.

** C-u C-x = provides detailed information about the character at

point in a pop-up window.

** Emacs can now support 'wheeled' mice (such as the MS IntelliMouse)

under XFree86. To enable this, use the 'mouse-wheel-mode' command, or

customize the variable 'mouse-wheel-mode'.

The variables 'mouse-wheel-follow-mouse' and 'mouse-wheel-scroll-amount'

determine where and by how much buffers are scrolled.

** Emacs' auto-save list files are now by default stored in a

sub-directory `.emacs.d/auto-save-list/' of the user's home directory.

(On MS-DOS, this subdirectory's name is `_emacs.d/auto-save.list/'.)

You can customize 'auto-save-list-file-prefix' to change this location.

** The function 'getenv' is now callable interactively.

** The new user-option 'even-window-heights' can be set to nil

to prevent 'display-buffer' from evening out window heights.

** The new command M-x delete-trailing-whitespace RET will delete the

trailing whitespace within the current restriction. You can also add

this function to 'write-file-hooks' or 'local-write-file-hooks'.

** When visiting a file with M-x find-file-literally, no newlines will

be added to the end of the buffer even if 'require-final-newline' is

non-nil.

** The new user-option 'find-file-suppress-same-file-warnings' can be

set to suppress warnings ``X and Y are the same file'' when visiting a

file that is already visited under a different name.

** The new user-option 'electric-help-shrink-window' can be set to

nil to prevent adjusting the help window size to the buffer size.

** New command M-x describe-character-set reads a character set name

and displays information about that.

** The new variable 'auto-mode-interpreter-regexp' contains a regular

expression matching interpreters, for file mode determination.

This regular expression is matched against the first line of a file to

determine the file's mode in 'set-auto-mode' when Emacs can't deduce a

mode from the file's name. If it matches, the file is assumed to be

interpreted by the interpreter matched by the second group of the

regular expression. The mode is then determined as the mode

associated with that interpreter in 'interpreter-mode-alist'.

** New function 'executable-make-buffer-file-executable-if-script-p' is

suitable as an 'after-save-hook' as an alternative to 'executable-chmod'.

** The most preferred coding-system is now used to save a buffer if

buffer-file-coding-system is 'undecided' and it is safe for the buffer

contents. (The most preferred is set by set-language-environment or

by M-x prefer-coding-system.) Thus if you visit an ASCII file and

insert a non-ASCII character from your current language environment,

the file will be saved silently with the appropriate coding.

Previously you would be prompted for a safe coding system.

** The many obsolete language `setup-...-environment' commands have

been removed -- use 'set-language-environment'.

** The new Custom option 'keyboard-coding-system' specifies a coding

system for keyboard input.

** New variable 'inhibit-iso-escape-detection' determines if Emacs'

coding system detection algorithm should pay attention to ISO2022's

escape sequences. If this variable is non-nil, the algorithm ignores

such escape sequences. The default value is nil, and it is

recommended not to change it except for the special case that you

always want to read any escape code verbatim. If you just want to

read a specific file without decoding escape codes, use C-x RET c

('universal-coding-system-argument'). For instance, C-x RET c latin-1

RET C-x C-f filename RET.

** Variable 'default-korean-keyboard' is initialized properly from the

environment variable `HANGUL_KEYBOARD_TYPE'.

** New command M-x list-charset-chars reads a character set name and

displays all characters in that character set.

** M-x set-terminal-coding-system (C-x RET t) now allows CCL-based

coding systems such as cpXXX and cyrillic-koi8.

** Emacs now attempts to determine the initial language environment

and preferred and locale coding systems systematically from the

LC_ALL, LC_CTYPE, and LANG environment variables during startup.

** New language environments 'Polish', 'Latin-8' and 'Latin-9'.

Latin-8 and Latin-9 correspond respectively to the ISO character sets

8859-14 (Celtic) and 8859-15 (updated Latin-1, with the Euro sign).

GNU Intlfonts doesn't support these yet but recent X releases have

8859-15. See etc/INSTALL for information on obtaining extra fonts.

There are new Leim input methods for Latin-8 and Latin-9 prefix (only)

and Polish 'slash'.

** New language environments 'Dutch' and 'Spanish'.

These new environments mainly select appropriate translations

of the tutorial.

** In Ethiopic language environment, special key bindings for

function keys are changed as follows. This is to conform to "Emacs

Lisp Coding Convention".

new command old-binding

--- ------- -----------

f3 'ethio-fidel-to-sera-buffer' f5

S-f3 'ethio-fidel-to-sera-region' f5

C-f3 'ethio-fidel-to-sera-mail-or-marker' f5

f4 'ethio-sera-to-fidel-buffer' unchanged

S-f4 'ethio-sera-to-fidel-region' unchanged

C-f4 'ethio-sera-to-fidel-mail-or-marker' unchanged

S-f5 'ethio-toggle-punctuation' f3

S-f6 'ethio-modify-vowel' f6

S-f7 'ethio-replace-space' f7

S-f8 'ethio-input-special-character' f8

S-f9 'ethio-replace-space' unchanged

C-f9 'ethio-toggle-space' f2

** There are new Leim input methods.

New input methods "turkish-postfix", "turkish-alt-postfix",

"greek-mizuochi", "TeX", and "greek-babel" are now part of the Leim

package.

** The rule of input method "slovak" is slightly changed. Now the

rules for translating "q" and "Q" to "`" (backquote) are deleted, thus

typing them inserts "q" and "Q" respectively. Rules for translating

"=q", "+q", "=Q", and "+Q" to "`" are also deleted. Now, to input

"`", you must type "=q".

** When your terminal can't display characters from some of the ISO

8859 character sets but can display Latin-1, you can display

more-or-less mnemonic sequences of ASCII/Latin-1 characters instead of

empty boxes (under a window system) or question marks (not under a

window system). Customize the option 'latin1-display' to turn this

on.

** M-; now calls 'comment-dwim' which tries to do something clever based

on the context. M-x kill-comment is now an alias to 'comment-kill',

defined in newcomment.el. You can choose different styles of region

commenting with the variable 'comment-style'.

** New user options 'display-time-mail-face' and

'display-time-use-mail-icon' control the appearance of mode-line mail

indicator used by the display-time package. On a suitable display the

indicator can be an icon and is mouse-sensitive.

** On window-systems, additional space can be put between text lines

on the display using several methods

- By setting frame parameter 'line-spacing' to PIXELS. PIXELS must be

a positive integer, and specifies that PIXELS number of pixels should

be put below text lines on the affected frame or frames.

- By setting X resource 'lineSpacing', class 'LineSpacing'. This is

equivalent to specifying the frame parameter.

- By specifying '--line-spacing=N' or `-lsp N' on the command line.

- By setting buffer-local variable 'line-spacing'. The meaning is

the same, but applies to the a particular buffer only.

** The new command 'clone-indirect-buffer' can be used to create

an indirect buffer that is a twin copy of the current buffer. The

command 'clone-indirect-buffer-other-window', bound to C-x 4 c,

does the same but displays the indirect buffer in another window.

** New user options 'backup-directory-alist' and

'make-backup-file-name-function' control the placement of backups,

typically in a single directory or in an invisible sub-directory.

** New commands 'iso-iso2sgml' and 'iso-sgml2iso' convert between Latin-1

characters and the corresponding SGML (HTML) entities.

** New X resources recognized

*** The X resource 'synchronous', class 'Synchronous', specifies

whether Emacs should run in synchronous mode. Synchronous mode

is useful for debugging X problems.

Example:

emacs.synchronous: true

*** The X resource `visualClass, class 'VisualClass', specifies the

visual Emacs should use. The resource's value should be a string of

the form 'CLASS-DEPTH', where CLASS is the name of the visual class,

and DEPTH is the requested color depth as a decimal number. Valid

visual class names are

TrueColor

PseudoColor

DirectColor

StaticColor

GrayScale

StaticGray

Visual class names specified as X resource are case-insensitive, i.e.

'pseudocolor', 'Pseudocolor' and 'PseudoColor' all have the same

meaning.

The program 'xdpyinfo' can be used to list the visual classes

supported on your display, and which depths they have. If

'visualClass' is not specified, Emacs uses the display's default

visual.

Example:

emacs.visualClass: TrueColor-8

*** The X resource 'privateColormap', class 'PrivateColormap',

specifies that Emacs should use a private colormap if it is using the

default visual, and that visual is of class PseudoColor. Recognized

resource values are 'true' or 'on'.

Example:

emacs.privateColormap: true

** Faces and frame parameters.

There are four new faces 'scroll-bar', 'border', 'cursor' and 'mouse'.

Setting the frame parameters 'scroll-bar-foreground' and

'scroll-bar-background' sets foreground and background color of face

'scroll-bar' and vice versa. Setting frame parameter 'border-color'

sets the background color of face 'border' and vice versa. Likewise

for frame parameters 'cursor-color' and face 'cursor', and frame

parameter 'mouse-color' and face 'mouse'.

Changing frame parameter 'font' sets font-related attributes of the

'default' face and vice versa. Setting frame parameters

'foreground-color' or 'background-color' sets the colors of the

'default' face and vice versa.

** New face 'menu'.

The face 'menu' can be used to change colors and font of Emacs' menus.

** New frame parameter 'screen-gamma' for gamma correction.

The new frame parameter 'screen-gamma' specifies gamma-correction for

colors. Its value may be nil, the default, in which case no gamma

correction occurs, or a number > 0, usually a float, that specifies

the screen gamma of a frame's display.

PC monitors usually have a screen gamma of 2.2. smaller values result

in darker colors. You might want to try a screen gamma of 1.5 for LCD

color displays. The viewing gamma Emacs uses is 0.4545. (1/2.2).

The X resource name of this parameter is 'screenGamma', class

'ScreenGamma'.

** Tabs and variable-width text.

Tabs are now displayed with stretch properties; the width of a tab is

defined as a multiple of the normal character width of a frame, and is

independent of the fonts used in the text where the tab appears.

Thus, tabs can be used to line up text in different fonts.

** Enhancements of the Lucid menu bar

*** The Lucid menu bar now supports the resource "margin".

emacs.pane.menubar.margin: 5

The default margin is 4 which makes the menu bar appear like the

LessTif/Motif one.

*** Arrows that indicate sub-menus are now drawn with shadows, as in

LessTif and Motif.

** A block cursor can be drawn as wide as the glyph under it under X.

As an example: if a block cursor is over a tab character, it will be

drawn as wide as that tab on the display. To do this, set

'x-stretch-cursor' to a non-nil value.

** Empty display lines at the end of a buffer may be marked with a

bitmap (this is similar to the tilde displayed by vi and Less).

This behavior is activated by setting the buffer-local variable

'indicate-empty-lines' to a non-nil value. The default value of this

variable is found in 'default-indicate-empty-lines'.

** There is a new "aggressive" scrolling method.

When scrolling up because point is above the window start, if the

value of the buffer-local variable 'scroll-up-aggressively' is a

number, Emacs chooses a new window start so that point ends up that

fraction of the window's height from the top of the window.

When scrolling down because point is below the window end, if the

value of the buffer-local variable 'scroll-down-aggressively' is a

number, Emacs chooses a new window start so that point ends up that

fraction of the window's height from the bottom of the window.

** You can now easily create new *Info* buffers using either

M-x clone-buffer, C-u m <entry> RET or C-u g <entry> RET.

M-x clone-buffer can also be used on *Help* and several other special

buffers.

** The command 'Info-search' now uses a search history.

** Listing buffers with M-x list-buffers (C-x C-b) now shows

abbreviated file names. Abbreviations can be customized by changing

'directory-abbrev-alist'.

** A new variable, 'backup-by-copying-when-privileged-mismatch', gives

the highest file uid for which 'backup-by-copying-when-mismatch' will be

forced on. The assumption is that uids less than or equal to this

value are special uids (root, bin, daemon, etc.--not real system

users) and that files owned by these users should not change ownership,

even if your system policy allows users other than root to edit them.

The default is 200; set the variable to nil to disable the feature.

** The rectangle commands now avoid inserting undesirable spaces,

notably at the end of lines.

All these functions have been rewritten to avoid inserting unwanted

spaces, and an optional prefix now allows them to behave the old way.

** The function 'replace-rectangle' is an alias for 'string-rectangle'.

** The new command M-x string-insert-rectangle is like 'string-rectangle',

but inserts text instead of replacing it.

** The new command M-x query-replace-regexp-eval acts like

query-replace-regexp, but takes a Lisp expression which is evaluated

after each match to get the replacement text.

** M-x query-replace recognizes a new command 'e' (or 'E') that lets

you edit the replacement string.

** The new command 'mail-abbrev-complete-alias', bound to 'M-TAB'

(if you load the library 'mailabbrev'), lets you complete mail aliases

in the text, analogous to 'lisp-complete-symbol'.

** The variable 'echo-keystrokes' may now have a floating point value.

** If your init file is compiled (.emacs.elc), 'user-init-file' is set

to the source name (.emacs.el), if that exists, after loading it.

** The help string specified for a menu-item whose definition contains

the property `:help HELP' is now displayed under X, on MS-Windows, and

MS-DOS, either in the echo area or with tooltips. Many standard menus

displayed by Emacs now have help strings.

--

** New user option 'read-mail-command' specifies a command to use to

read mail from the menu etc.

** The environment variable 'EMACSLOCKDIR' is no longer used on MS-Windows.

This environment variable was used when creating lock files. Emacs on

MS-Windows does not use this variable anymore. This change was made

before Emacs 21.1, but wasn't documented until now.

** Highlighting of mouse-sensitive regions is now supported in the

MS-DOS version of Emacs.

** The new command 'msdos-set-mouse-buttons' forces the MS-DOS version

of Emacs to behave as if the mouse had a specified number of buttons.

This comes handy with mice that don't report their number of buttons

correctly. One example is the wheeled mice, which report 3 buttons,

but clicks on the middle button are not passed to the MS-DOS version

of Emacs.

** Customize changes

*** Customize now supports comments about customized items. Use the

'State' menu to add comments, or give a prefix argument to

M-x customize-set-variable or M-x customize-set-value. Note that

customization comments will cause the customizations to fail in

earlier versions of Emacs.

*** The new option 'custom-buffer-done-function' says whether to kill

Custom buffers when you've done with them or just bury them (the

default).

*** If Emacs was invoked with the '-q' or '--no-init-file' options, it

does not allow you to save customizations in your `~/.emacs' init

file. This is because saving customizations from such a session would

wipe out all the other customizations you might have on your init

file.

** If Emacs was invoked with the '-q' or '--no-init-file' options, it

does not save disabled and enabled commands for future sessions, to

avoid overwriting existing customizations of this kind that are

already in your init file.

** New features in evaluation commands

*** The commands to evaluate Lisp expressions, such as C-M-x in Lisp

modes, C-j in Lisp Interaction mode, and M-:, now bind the variables

'print-level', 'print-length', and 'debug-on-error' based on the new

customizable variables 'eval-expression-print-level',

'eval-expression-print-length', and 'eval-expression-debug-on-error'.

The default values for the first two of these variables are 12 and 4

respectively, which means that 'eval-expression' now prints at most

the first 12 members of a list and at most 4 nesting levels deep (if

the list is longer or deeper than that, an ellipsis `...' is

printed).

<RET> or <mouse-2> on the printed text toggles between an abbreviated

printed representation and an unabbreviated one.

The default value of eval-expression-debug-on-error is t, so any error

during evaluation produces a backtrace.

*** The function 'eval-defun' (C-M-x) now loads Edebug and instruments

code when called with a prefix argument.

** CC mode changes.

Note: This release contains changes that might not be compatible with

current user setups (although it's believed that these

incompatibilities will only show in very uncommon circumstances).

However, since the impact is uncertain, these changes may be rolled

back depending on user feedback. Therefore there's no forward

compatibility guarantee wrt the new features introduced in this

release.

*** The hardcoded switch to "java" style in Java mode is gone.

CC Mode used to automatically set the style to "java" when Java mode

is entered. This has now been removed since it caused too much

confusion.

However, to keep backward compatibility to a certain extent, the

default value for c-default-style now specifies the "java" style for

java-mode, but "gnu" for all other modes (as before). So you won't

notice the change if you haven't touched that variable.

*** New cleanups, space-before-funcall and compact-empty-funcall.

Two new cleanups have been added to c-cleanup-list:

space-before-funcall causes a space to be inserted before the opening

parenthesis of a function call, which gives the style "foo (bar)".

compact-empty-funcall causes any space before a function call opening

parenthesis to be removed if there are no arguments to the function.

It's typically useful together with space-before-funcall to get the

style "foo (bar)" and "foo()".

*** Some keywords now automatically trigger reindentation.

Keywords like "else", "while", "catch" and "finally" have been made

"electric" to make them reindent automatically when they continue an

earlier statement. An example:

for (i = 0; i < 17; i++)

if (a[i])

res += a[i]->offset;

else

Here, the "else" should be indented like the preceding "if", since it

continues that statement. CC Mode will automatically reindent it after

the "else" has been typed in full, since it's not until then it's

possible to decide whether it's a new statement or a continuation of

the preceding "if".

CC Mode uses Abbrev mode to achieve this, which is therefore turned on

by default.

*** M-a and M-e now moves by sentence in multiline strings.

Previously these two keys only moved by sentence in comments, which

meant that sentence movement didn't work in strings containing

documentation or other natural language text.

The reason it's only activated in multiline strings (i.e. strings that

contain a newline, even when escaped by a '\') is to avoid stopping in

the short strings that often reside inside statements. Multiline

strings almost always contain text in a natural language, as opposed

to other strings that typically contain format specifications,

commands, etc. Also, it's not that bothersome that M-a and M-e misses

sentences in single line strings, since they're short anyway.

*** Support for autodoc comments in Pike mode.

Autodoc comments for Pike are used to extract documentation from the

source, like Javadoc in Java. Pike mode now recognize this markup in

comment prefixes and paragraph starts.

*** The comment prefix regexps on c-comment-prefix may be mode specific.

When c-comment-prefix is an association list, it specifies the comment

line prefix on a per-mode basis, like c-default-style does. This

change came about to support the special autodoc comment prefix in

Pike mode only.

*** Better handling of syntactic errors.

The recovery after unbalanced parens earlier in the buffer has been

improved; CC Mode now reports them by dinging and giving a message

stating the offending line, but still recovers and indent the

following lines in a sane way (most of the time). An "else" with no

matching "if" is handled similarly. If an error is discovered while

indenting a region, the whole region is still indented and the error

is reported afterwards.

*** Lineup functions may now return absolute columns.

A lineup function can give an absolute column to indent the line to by

returning a vector with the desired column as the first element.

*** More robust and warning-free byte compilation.

Although this is strictly not a user visible change (well, depending

on the view of a user), it's still worth mentioning that CC Mode now

can be compiled in the standard ways without causing trouble. Some

code have also been moved between the subpackages to enhance the

modularity somewhat. Thanks to Martin Buchholz for doing the

groundwork.

*** c-style-variables-are-local-p now defaults to t.

This is an incompatible change that has been made to make the behavior

of the style system wrt global variable settings less confusing for

non-advanced users. If you know what this variable does you might

want to set it to nil in your .emacs, otherwise you probably don't

have to bother.

Defaulting c-style-variables-are-local-p to t avoids the confusing

situation that occurs when a user sets some style variables globally

and edits both a Java and a non-Java file in the same Emacs session.

If the style variables aren't buffer local in this case, loading of

the second file will cause the default style (either "gnu" or "java"

by default) to override the global settings made by the user.

*** New initialization procedure for the style system.

When the initial style for a buffer is determined by CC Mode (from the

variable c-default-style), the global values of style variables now

take precedence over the values specified by the chosen style. This

is different than the old behavior: previously, the style-specific

settings would override the global settings. This change makes it

possible to do simple configuration in the intuitive way with

Customize or with setq lines in one's .emacs file.