--- /dev/null
- Copyright (C) 2016-2017 Free Software Foundation, Inc.
+GNU Emacs NEWS -- history of user-visible changes.
+
++Copyright (C) 2016-2018 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 26.
+
+See file HISTORY for a list of GNU Emacs versions and release dates.
+See files NEWS.25, NEWS.24, ..., 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 have been done.
+ (This means all the relevant manuals in doc/ AND lisp doc-strings.)
+--- means doc strings are updated, and no change in the manuals is needed.
+When you add a new item, use the appropriate mark if you are sure it applies,
+
+\f
+* Installation Changes in Emacs 26.1
+
+---
+** By default libgnutls is now required when building Emacs.
+Use 'configure --with-gnutls=no' to build even when GnuTLS is missing.
+
+---
+** GnuTLS version 2.12.2 or later is now required, instead of merely
+version 2.6.6 or later.
+
++++
+** The new option 'configure --with-mailutils' causes Emacs to rely on
+GNU Mailutils to retrieve email. It is recommended, and is the
+default if GNU Mailutils is installed. When --with-mailutils is not
+in effect, the Emacs build procedure by default continues to build and
+install a limited 'movemail' substitute that retrieves POP3 email only
+via insecure channels. To avoid this problem, use either
+--with-mailutils or --without-pop when configuring; --without-pop
+is the default on platforms other than native MS-Windows.
+
+---
+** The new option 'configure --enable-gcc-warnings=warn-only' causes
+GCC to issue warnings without stopping the build. This behavior is
+now the default in developer builds. As before, use
+'--disable-gcc-warnings' to suppress GCC's warnings, and
+'--enable-gcc-warnings' to stop the build if GCC issues warnings.
+
+---
+** When GCC warnings are enabled, '--enable-check-lisp-object-type' is
+now enabled by default when configuring.
+
++++
+** The Emacs server now has socket-launching support. This allows
+socket based activation, where an external process like systemd can
+invoke the Emacs server process upon a socket connection event and
+hand the socket over to Emacs. Emacs uses this socket to service
+emacsclient commands. This new functionality can be disabled with the
+configure option '--disable-libsystemd'.
+
++++
+** A systemd user unit file is provided. Use it in the standard way:
+'systemctl --user enable emacs'.
+(If your Emacs is installed in a non-standard location, you may
+need to copy the emacs.service file to eg ~/.config/systemd/user/)
+
+---
+** New configure option '--disable-build-details' attempts to build an
+Emacs that is more likely to be reproducible; that is, if you build
+and install Emacs twice, the second Emacs is a copy of the first.
+Deterministic builds omit the build date from the output of the
+'emacs-version' and 'erc-cmd-SV' functions, and the leave the
+following variables nil: 'emacs-build-system', 'emacs-build-time',
+'erc-emacs-build-time'.
+
+---
+** Emacs can now be built with support for Little CMS.
+
+If the lcms2 library is installed, Emacs will enable features built on
+top of that library. The new configure option '--without-lcms2' can
+be used to build without lcms2 support even if it is installed. Emacs
+linked to Little CMS exposes color management functions in Lisp: the
+color metrics 'lcms-cie-de2000' and 'lcms-cam02-ucs', as well as
+functions for conversion to and from CIE CAM02 and CAM02-UCS.
+
+---
+** The configure option '--with-gameuser' now defaults to 'no',
+as this appears to be the most common configuration in practice.
+When it is 'no', the shared game directory and the auxiliary program
+update-game-score are no longer needed and are not installed.
+
+---
+** Emacs no longer works on IRIX. We expect that Emacs users are not
+affected by this, as SGI stopped supporting IRIX in December 2013.
+
+\f
+* Startup Changes in Emacs 26.1
+
++++
+** New option '--fg-daemon'. This is the same as '--daemon', except
+it runs in the foreground and does not fork. This is intended for
+modern init systems such as systemd, which manage many of the traditional
+aspects of daemon behavior themselves. '--bg-daemon' is now an alias
+for '--daemon'.
+
++++
+** New option '--module-assertions'.
+When given this option, Emacs will perform expensive correctness
+checks when dealing with dynamic modules. This is intended for module
+authors that wish to verify that their module conforms to the module
+requirements. The option makes Emacs abort if a module-related
+assertion triggers.
+
++++
+** Emacs now supports 24-bit colors on capable text terminals.
+Terminal is automatically initialized to use 24-bit colors if the
+required capabilities are found in terminfo. See the FAQ node
+"(efaq) Colors on a TTY" for more information.
+
++++
+** Emacs now obeys the X resource "scrollBar" at startup.
+The effect is similar to that of "toolBar" resource on the tool bar.
+
+\f
+* Changes in Emacs 26.1
+
++++
+** Option 'buffer-offer-save' can be set to new value, 'always'. When
+set to 'always', the command 'save-some-buffers' will always offer
+this buffer for saving.
+
+** Security vulnerability related to Enriched Text mode is removed.
+
++++
+*** Enriched Text mode does not evaluate Lisp in 'display' properties.
+This feature allows saving 'display' properties as part of text.
+Emacs 'display' properties support evaluation of arbitrary Lisp forms
+as part of processing the property for display, so displaying Enriched
+Text could be vulnerable to executing arbitrary malicious Lisp code
+included in the text (e.g., sent as part of an email message).
+Therefore, execution of arbitrary Lisp forms in 'display' properties
+decoded by Enriched Text mode is now disabled by default. Customize
+the new option 'enriched-allow-eval-in-display-props' to a non-nil
+value to allow Lisp evaluation in decoded 'display' properties.
+
+This vulnerability was introduced in Emacs 21.1. To work around that
+in Emacs versions before 25.3, append the following to your ~/.emacs
+init file:
+
+ (eval-after-load "enriched"
+ '(defun enriched-decode-display-prop (start end &optional param)
+ (list start end)))
+
++++
+** Functions in 'write-contents-functions' can fully short-circuit the
+'save-buffer' process. Previously, saving a buffer that was not
+visiting a file would always prompt for a file name. Now it only does
+so if 'write-contents-functions' is nil (or all its functions return
+nil).
+
+---
+** New variable 'executable-prefix-env' for inserting magic signatures.
+This variable affects the format of the interpreter magic number
+inserted by 'executable-set-magic'. If non-nil, the magic number now
+takes the form "#!/usr/bin/env interpreter", otherwise the value
+determined by 'executable-prefix', which is by default
+"#!/path/to/interpreter". By default, 'executable-prefix-env' is nil,
+so the default behavior is not changed.
+
++++
+** The variable 'emacs-version' no longer includes the build number.
+This is now stored separately in a new variable, 'emacs-build-number'.
+
++++
+** Emacs now provides a limited form of concurrency with Lisp threads.
+Concurrency in Emacs Lisp is "mostly cooperative", meaning that
+Emacs will only switch execution between threads at well-defined
+times: when Emacs waits for input, during blocking operations related
+to threads (such as mutex locking), or when the current thread
+explicitly yields. Global variables are shared among all threads, but
+a 'let' binding is thread-local. Each thread also has its own current
+buffer and its own match data.
+
+See the chapter "(elisp) Threads" in the ELisp manual for full
+documentation of these facilities.
+
++++
+** The new user variable 'electric-quote-chars' provides a list
+of curved quotes for 'electric-quote-mode', allowing user to choose
+the types of quotes to be used.
+
+---
+** The new user option 'electric-quote-context-sensitive' makes
+'electric-quote-mode' context sensitive. If it is non-nil, you can
+type an ASCII apostrophe to insert an opening or closing quote,
+depending on context. Emacs will replace the apostrophe by an opening
+quote character at the beginning of the buffer, the beginning of a
+line, after a whitespace character, and after an opening parenthesis;
+and it will replace the apostrophe by a closing quote character in all
+other cases.
+
+---
+** The new variable 'electric-quote-inhibit-functions' controls when
+to disable electric quoting based on context. Major modes can add
+functions to this list; Emacs will temporarily disable
+'electric-quote-mode' whenever any of the functions returns non-nil.
+This can be used by major modes that derive from 'text-mode' but allow
+inline code segments, such as 'markdown-mode'.
+
++++
+** The new user variable 'dired-omit-case-fold' allows the user to
+customize the case-sensitivity of dired-omit-mode. It defaults to
+the same sensitivity as that of the filesystem for the corresponding
+dired buffer.
+
++++
+** Emacs now uses double buffering to reduce flicker when editing and
+resizing graphical Emacs frames on the X Window System. This support
+requires the DOUBLE-BUFFER extension, which major X servers have
+supported for many years. If your system has this extension, but an
+Emacs built with double buffering misbehaves on some displays you use,
+you can disable the feature by adding
+
+ '(inhibit-double-buffering . t)
+
+to default-frame-alist. Or inject this parameter into the selected
+frame by evaluating this form:
+
+ (modify-frame-parameters nil '((inhibit-double-buffering . t)))
+
+---
+** The customization group 'wp', whose label was "text", is now
+deprecated. Use the new group 'text', which inherits from 'wp',
+instead.
+
++++
+** The new function 'call-shell-region' executes a command in an
+inferior shell with the buffer region as input.
+
++++
+** The new user option 'shell-command-dont-erase-buffer' controls
+if the output buffer is erased between shell commands; if non-nil,
+the output buffer is not erased; this variable also controls where
+to set the point in the output buffer: beginning of the output,
+end of the buffer or save the point.
+When 'shell-command-dont-erase-buffer' is nil, the default value,
+the behavior of 'shell-command', 'shell-command-on-region' and
+'async-shell-command' is as usual.
+
++++
+** The new user option 'async-shell-command-display-buffer' controls
+whether the output buffer of an asynchronous command is shown
+immediately, or only when there is output.
+
++++
+** New user option 'mouse-select-region-move-to-beginning'.
+This option controls the position of point when double-clicking
+mouse-1 on the end of a parenthetical grouping or string-delimiter:
+the default value nil keeps point at the end of the region, setting it
+to non-nil moves point to the beginning of the region.
+
++++
+** New user option 'mouse-drag-and-drop-region'.
+This option allows to drag the entire region of text to another place
+or another buffer. Its behavior is customizable via the new options
+'mouse-drag-and-drop-region-cut-when-buffers-differ',
+'mouse-drag-and-drop-region-show-tooltip', and
+'mouse-drag-and-drop-region-show-cursor'.
+
++++
+** The new user option 'confirm-kill-processes' allows the user to
+skip a confirmation prompt for killing subprocesses when exiting
+Emacs. When set to t (the default), Emacs will prompt for
+confirmation before killing subprocesses on exit, which is the same
+behavior as before.
+
+---
+** 'find-library-name' will now fall back on looking at 'load-history'
+to try to locate libraries that have been loaded with an explicit path
+outside 'load-path'.
+
++++
+** Faces in 'minibuffer-prompt-properties' no longer overwrite properties
+in the text in functions like 'read-from-minibuffer', but instead are
+added to the end of the face list. This allows users to say things
+like '(read-from-minibuffer (propertize "Enter something: " 'face 'bold))'.
+
++++
+** The new variable 'extended-command-suggest-shorter' has been added
+to control whether to suggest shorter 'M-x' commands or not.
+
+---
+** icomplete now respects 'completion-ignored-extensions'.
+
++++
+** Non-breaking hyphens are now displayed with the 'nobreak-hyphen'
+face instead of the 'escape-glyph' face.
+
++++
+** Approximations to quotes are now displayed with the new 'homoglyph'
+face instead of the 'escape-glyph' face.
+
++++
+** New face 'header-line-highlight'.
+This face is the header-line analogue of 'mode-line-highlight'; it
+should be the preferred mouse-face for mouse-sensitive elements in the
+header line.
+
+---
+** 'C-x h' ('mark-whole-buffer') will now avoid marking the prompt
+part of minibuffers.
+
+---
+** 'fill-paragraph' no longer marks the buffer as changed unless it
+actually changed something.
+
+---
+** The locale language name 'ca' is now mapped to the language
+environment 'Catalan', which has been added.
+
+---
+** 'align-regexp' has a separate history for its interactive argument.
+'align-regexp' no longer shares its history with all other
+history-less functions that use 'read-string'.
+
++++
+** The networking code has been reworked so that it's more
+asynchronous than it was (when specifying :nowait t in
+'make-network-process'). How asynchronous it is varies based on the
+capabilities of the system, but on a typical GNU/Linux system the DNS
+resolution, the connection, and (for TLS streams) the TLS negotiation
+are all done without blocking the main Emacs thread. To get
+asynchronous TLS, the TLS boot parameters have to be passed in (see
+the manual for details).
+
+Certain process oriented functions (like 'process-datagram-address')
+will block until socket setup has been performed. The recommended way
+to deal with asynchronous sockets is to avoid interacting with them
+until they have changed status to "run". This is most easily done
+from a process sentinel.
+
+---
+** 'make-network-process' and 'open-network-stream' sometimes allowed
+:service to be an integer string (e.g., :service "993") and sometimes
+required an integer (e.g., :service 993). This difference has been
+eliminated, and integer strings work everywhere.
+
+---
+** It is possible to disable attempted recovery on fatal signals.
+Two new variables support disabling attempts to recover from stack
+overflow and to avoid automatic auto-save when Emacs is delivered a
+fatal signal. 'attempt-stack-overflow-recovery', if set to nil,
+will disable attempts to recover from C stack overflows; Emacs will
+then crash as with any other fatal signal.
+'attempt-orderly-shutdown-on-fatal-signal', if set to nil, will
+disable attempts to auto-save the session and shut down in an orderly
+fashion when Emacs receives a fatal signal; instead, Emacs will
+terminate immediately. Both variables are non-nil by default.
+These variables are for users who would like to avoid the small
+probability of data corruption due to techniques Emacs uses to recover
+in these situations.
+
++++
+** File local and directory local variables are now initialized each
+time the major mode is set, not just when the file is first visited.
+These local variables will thus not vanish on setting a major mode.
+
++++
+** A second dir-local file (.dir-locals-2.el) is now accepted.
+See the doc string of 'dir-locals-file' for more information.
+
++++
+** Connection-local variables can be used to specify local variables
+with a value depending on the connected remote server. For details,
+see the node "(elisp) Connection Local Variables" in the ELisp manual.
+
+---
+** International domain names (IDNA) are now encoded via the new
+puny.el library, so that one can visit Web sites with non-ASCII URLs.
+
++++
+** The new 'list-timers' command lists all active timers in a buffer,
+where you can cancel them with the 'c' command.
+
++++
+** 'switch-to-buffer-preserve-window-point' now defaults to t.
+Applications that call 'switch-to-buffer' and want to show the buffer at
+the position of its point should use 'pop-to-buffer-same-window' in lieu
+of 'switch-to-buffer'.
+
++++
+** The new variable 'debugger-stack-frame-as-list' allows displaying
+all call stack frames in a Lisp backtrace buffer as lists. Both
+debug.el and edebug.el have been updated to heed to this variable.
+
+---
+** Values in call stack frames are now displayed using 'cl-prin1'.
+The old behavior of using 'prin1' can be restored by customizing the
+new option 'debugger-print-function'.
+
++++
+** NUL bytes in text copied to the system clipboard are now replaced with "\0".
+
++++
+** The new variable 'x-ctrl-keysym' has been added to the existing
+roster of X keysyms. It can be used in combination with another
+variable of this kind to swap modifiers in Emacs.
+
+---
+** New input methods: 'cyrillic-tuvan', 'polish-prefix', 'uzbek-cyrillic'.
+
+---
+** The 'dutch' input method no longer attempts to support Turkish too.
+Also, it no longer converts 'IJ' and 'ij' to the compatibility
+characters U+0132 LATIN CAPITAL LIGATURE IJ and U+0133 LATIN SMALL
+LIGATURE IJ.
+
++++
+** File name quoting by adding the prefix "/:" is now possible for the
+local part of a remote file name. Thus, if you have a directory named
+"/~" on the remote host "foo", you can prevent it from being
+substituted by a home directory by writing it as "/foo:/:/~/file".
+
++++
+** The new variable 'maximum-scroll-margin' allows having effective
+settings of 'scroll-margin' up to half the window size, instead of
+always restricting the margin to a quarter of the window.
+
++++
+** Emacs can scroll horizontally using mouse, touchpad, and trackbar.
+You can enable this by customizing 'mwheel-tilt-scroll-p'. If you
+want to reverse the direction of the scroll, customize
+'mwheel-flip-direction'.
+
++++
+** The default GnuTLS priority string now includes %DUMBFW.
+This is to avoid bad behavior in some firewalls, which causes the
+connection to be closed by the remote host.
+
+** Emacsclient changes
+
++++
+*** Emacsclient has a new option '-u' / '--suppress-output'.
+This option suppresses display of return values from the server
+process.
+
++++
+*** Emacsclient has a new option '-T' / '--tramp'.
+This helps with using a local Emacs session as the server for a remote
+emacsclient. With appropriate setup, one can now set the EDITOR
+environment variable on a remote machine to emacsclient, and
+use the local Emacs to edit remote files via Tramp. See the node
+"(emacs) emacsclient Options" in the user manual for the details.
+
++++
+*** Emacsclient now accepts command-line options in ALTERNATE_EDITOR
+and '--alternate-editor'. For example, ALTERNATE_EDITOR="emacs -Q -nw".
+Arguments may be quoted "like this", so that for example an absolute
+path containing a space may be specified; quote escaping is not
+supported.
+
+---
+** New user option 'dig-program-options' and extended functionality
+for DNS-querying functions 'nslookup-host', 'dns-lookup-host',
+and 'run-dig'. Each function now accepts an optional name server
+argument interactively (with a prefix argument) and non-interactively.
+
++++
+** 'describe-key-briefly' now ignores mouse movement events.
+
++++
+** The new variable 'eval-expression-print-maximum-character' prevents
+large integers from being displayed as characters by 'M-:' and similar
+commands.
+
+---
+** Two new commands for finding the source code of Emacs Lisp
+libraries: 'find-library-other-window' and 'find-library-other-frame'.
+
++++
+** The new variable 'display-raw-bytes-as-hex' allows to change the
+display of raw bytes from octal to hex.
+
++++
+** You can now provide explicit field numbers in format specifiers.
+For example, '(format "%2$s %1$s %2$s" "X" "Y")' produces "Y X Y".
+
++++
+** Emacs now supports optional display of line numbers in the buffer.
+This is similar to what 'linum-mode' provides, but much faster and
+doesn't usurp the display margin for the line numbers. Customize the
+buffer-local variable 'display-line-numbers' to activate this optional
+display. Alternatively, you can use the 'display-line-numbers-mode'
+minor mode or the global 'global-display-line-numbers-mode'. When
+using these modes, customize 'display-line-numbers-type' with the same
+value as you would use with 'display-line-numbers'.
+
+Line numbers are not displayed at all in minibuffer windows and in
+tooltips, as they are not useful there.
+
+Lisp programs can disable line-number display for a particular screen
+line by putting the 'display-line-numbers-disable' text property or
+overlay property on the first character of that screen line. This is
+intended for add-on packages that need a finer control of the display.
+
+Lisp programs that need to know how much screen estate is used up for
+line-number display in a window can use the new function
+'line-number-display-width'.
+
+'linum-mode' and all similar packages are henceforth becoming obsolete.
+Users and developers are encouraged to switch to this new feature
+instead.
+
+---
+** The new user option 'arabic-shaper-ZWNJ-handling' controls how to
+handle ZWNJ in Arabic text rendering.
+
+\f
+* Editing Changes in Emacs 26.1
+
++++
+** New variable 'column-number-indicator-zero-based'.
+Traditionally, in Column Number mode, the displayed column number
+counts from zero starting at the left margin of the window. This
+behavior is now controlled by 'column-number-indicator-zero-based'.
+If you would prefer for the displayed column number to count from one,
+you may set this variable to nil. (Behind the scenes, there is now a
+new mode line construct, '%C', which operates exactly as '%c' does
+except that it counts from one.)
+
++++
+** New single-line horizontal scrolling mode.
+The 'auto-hscroll-mode' variable can now have a new special value,
+'current-line', which causes only the line where the cursor is
+displayed to be horizontally scrolled when lines are truncated on
+display and point moves outside the left or right window margin.
+
++++
+** New mode line constructs '%o' and '%q', and user option
+'mode-line-percent-position'. '%o' displays the "degree of travel" of
+the window through the buffer. Unlike the default '%p', this
+percentage approaches 100% as the window approaches the end of the
+buffer. '%q' displays the percentage offsets of both the start and
+the end of the window, e.g. "5-17%". The new option
+'mode-line-percent-position' makes it easier to switch between '%p',
+'%P', and these new constructs.
+
++++
+** Two new user options 'list-matching-lines-jump-to-current-line' and
+'list-matching-lines-current-line-face' to show the current line
+highlighted in *Occur* buffer.
+
++++
+** The 'occur' command can now operate on the region.
+
++++
+** New bindings for 'query-replace-map'.
+'undo', undo the last replacement; bound to 'u'.
+'undo-all', undo all replacements; bound to 'U'.
+
+---
+** 'delete-trailing-whitespace' deletes whitespace after form feed.
+In modes where form feed was treated as a whitespace character,
+'delete-trailing-whitespace' would keep lines containing it unchanged.
+It now deletes whitespace after the last form feed thus behaving the
+same as in modes where the character is not whitespace.
+
+---
+** Emacs no longer prompts about editing a changed file when the file's
+content is unchanged. Instead of only checking the modification time,
+Emacs now also checks the file's actual content before prompting the user.
+
+---
+** Various casing improvements.
+
+*** 'upcase', 'upcase-region' et al. convert title case characters
+(such as Dz) into their upper case form (such as DZ).
+
+*** 'capitalize', 'upcase-initials' et al. make use of title-case forms
+of initial characters (correctly producing for example Džungla instead
+of incorrect DŽungla).
+
+*** Characters which turn into multiple ones when cased are correctly handled.
+For example, fi ligature is converted to FI when upper cased.
+
+*** Greek small sigma is correctly handled when at the end of the word.
+Strings such as ΌΣΟΣ are now correctly converted to Όσος when
+capitalized instead of incorrect Όσοσ (compare lowercase sigma at the
+end of the word).
+
++++
+** Emacs can now auto-save buffers to visited files in a more robust
+manner via the new mode 'auto-save-visited-mode'. Unlike
+'auto-save-visited-file-name', this mode uses the normal saving
+procedure and therefore obeys saving hooks.
+'auto-save-visited-file-name' is now obsolete.
+
++++
+** New behavior of 'mark-defun'.
+Prefix argument selects that many (or that many more) defuns.
+Negative prefix arg flips the direction of selection. Also,
+'mark-defun' between defuns correctly selects N following defuns (or
+-N previous for negative arguments). Finally, comments preceding the
+defun are selected unless they are separated from the defun by a blank
+line.
+
+---
+** New command 'replace-buffer-contents'.
+This command replaces the contents of the accessible portion of the
+current buffer with the contents of the accessible portion of a
+different buffer while keeping point, mark, markers, and text
+properties as intact as possible.
+
++++
+** New commands 'apropos-local-variable' and 'apropos-local-value'.
+These are buffer-local versions of 'apropos-variable' and
+'apropos-value', respectively. They show buffer-local variables whose
+names and values, respectively, match a given pattern.
+
++++
+** More user control of reordering bidirectional text for display.
+The two new variables, 'bidi-paragraph-start-re' and
+'bidi-paragraph-separate-re', allow customization of what exactly are
+paragraphs, for the purposes of bidirectional display.
+
+---
+** 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).
+
+\f
+* Changes in Specialized Modes and Packages in Emacs 26.1
+
+---
+** Emacs 26.1 comes with Org v9.1.4.
+See the file ORG-NEWS for user-visible changes in Org.
+
+---
+** New function 'cl-generic-p'.
+
+** Dired
+
++++
+*** You can answer 'all' in 'dired-do-delete' to delete recursively all
+remaining directories without more prompts.
+
++++
+*** Dired supports wildcards in the directory part of the file names.
+
++++
+*** You can now use '`?`' in 'dired-do-shell-command'.
+It gets replaced by the current file name, like ' ? '.
+
++++
+*** A new option 'dired-always-read-filesystem' defaulting to nil.
+If non-nil, buffers visiting files are reverted before they are
+searched; for instance, in 'dired-mark-files-containing-regexp' a
+non-nil value of this option means the file is revisited in a
+temporary buffer; this temporary buffer is the actual buffer searched:
+the original buffer visiting the file is not modified.
+
+---
+*** Users can now customize mouse clicks in Dired in a more flexible way.
+The new command 'dired-mouse-find-file' can be bound to a mouse click
+and used to visit files/directories in Dired in the selected window.
+The new command 'dired-mouse-find-file-other-frame' similarly visits
+files/directories in another frame. You can write your own commands
+that invoke 'dired-mouse-find-file' with non-default optional
+arguments, to tailor the effects of mouse clicks on file names in
+Dired buffers.
+
++++
+*** In wdired, when editing files to contain slash characters,
+the resulting directories are automatically created. Whether to do
+this is controlled by the 'wdired-create-parent-directories' variable.
+
++++
+*** 'W' is now bound to 'browse-url-of-dired-file', and is useful for
+viewing HTML files and the like.
+
+---
+*** New variable 'dired-clean-confirm-killing-deleted-buffers'
+controls whether Dired asks to kill buffers visiting deleted files and
+directories. The default is t, so Dired asks for confirmation, to
+keep previous behavior.
+
+---
+** html2text is now marked obsolete.
+
+---
+** smerge-refine-regions can refine regions in separate buffers.
+
+---
+** Info menu and index completion uses substring completion by default.
+This can be customized via the 'info-menu' category in
+'completion-category-overrides'.
+
++++
+** The ancestor buffer is shown by default in 3-way merges.
+A new option 'ediff-show-ancestor' and a new toggle
+'ediff-toggle-show-ancestor'.
+
+---
+** TeX: Add luatex and xetex as alternatives to pdftex
+
+** Electric-Buffer-menu
+
++++
+*** Key 'U' is bound to 'Buffer-menu-unmark-all' and key 'M-DEL' is
+bound to 'Buffer-menu-unmark-all-buffers'.
+
++++
+** hideshow mode got four key bindings that are analogous to outline
+mode bindings: 'C-c @ C-a', 'C-c @ C-t', 'C-c @ C-d', and 'C-c @ C-e'.
+
+** bs
+
+---
+*** Two new commands 'bs-unmark-all', bound to 'U', and
+'bs-unmark-previous', bound to <backspace>.
+
+** Buffer-menu
+
++++
+*** Two new commands 'Buffer-menu-unmark-all', bound to 'U' and
+'Buffer-menu-unmark-all-buffers', bound to 'M-DEL'.
+
+---
+** Checkdoc
+
+*** 'checkdoc-arguments-in-order-flag' now defaults to nil.
+
+** Gnus
+
+---
+*** The ~/.newsrc file will now only be saved if the native select
+method is an NNTP select method.
+
++++
+*** A new command for sorting articles by readedness marks has been
+added: 'C-c C-s C-m C-m'.
+
++++
+*** In 'message-citation-line-format' the '%Z' format is now the time
+zone name instead of the numeric form. The '%z' format continues to
+be the numeric form. The new behavior is compatible with
+'format-time-string'.
+
+** Ibuffer
+
+---
+*** New command 'ibuffer-jump'.
+
+---
+*** New filter commands 'ibuffer-filter-by-basename',
+'ibuffer-filter-by-file-extension', 'ibuffer-filter-by-directory',
+'ibuffer-filter-by-starred-name', 'ibuffer-filter-by-modified'
+and 'ibuffer-filter-by-visiting-file'; bound respectively
+to '/b', '/.', '//', '/*', '/i' and '/v'.
+
+---
+*** Two new commands 'ibuffer-filter-chosen-by-completion'
+and 'ibuffer-and-filter', the second bound to '/&'.
+
+---
+*** The commands 'ibuffer-pop-filter', 'ibuffer-pop-filter-group',
+'ibuffer-or-filter' and 'ibuffer-filter-disable' have the alternative
+bindings '/<up>', '/S-<up>', '/|' and '/DEL', respectively.
+
+---
+*** The data format specifying filters has been extended to allow
+explicit logical 'and', and a more flexible form for logical 'not'.
+See 'ibuffer-filtering-qualifiers' doc string for full details.
+
+---
+*** A new command 'ibuffer-copy-buffername-as-kill'; bound
+to 'B'.
+
+---
+*** New command 'ibuffer-change-marks'; bound to '* c'.
+
+---
+*** A new command 'ibuffer-mark-by-locked' to mark
+all locked buffers; bound to '% L'.
+
+---
+*** A new option 'ibuffer-locked-char' to indicate
+locked buffers; Ibuffer shows a new column displaying
+'ibuffer-locked-char' for locked buffers.
+
+---
+*** A new command 'ibuffer-unmark-all-marks' to unmark
+all buffers without asking confirmation; bound to
+'U'; 'ibuffer-do-replace-regexp' bound to 'r'.
+
+---
+*** A new command 'ibuffer-mark-by-content-regexp' to mark buffers
+whose content matches a regexp; bound to '% g'.
+
+---
+*** Two new options 'ibuffer-never-search-content-name' and
+'ibuffer-never-search-content-mode' used by
+'ibuffer-mark-by-content-regexp'.
+
+** Browse-URL
+
+---
+*** Support for opening links to man pages in Man or WoMan mode.
+
+** Comint
+
+---
+*** New user option 'comint-move-point-for-matching-input' to control
+where to place point after 'C-c M-r' and 'C-c M-s'.
+
++++
+*** New user option 'comint-terminfo-terminal'.
+This option allows control of the value of the TERM environment
+variable Emacs puts into the environment of the Comint mode and its
+derivatives, such as Shell mode and Compilation Shell minor-mode. The
+default is "dumb", for compatibility with previous behavior.
+
+** Compilation mode
+
+---
+*** Messages from CMake are now recognized.
+
++++
+*** The number of errors, warnings, and informational messages is now
+displayed in the mode line. These are updated as compilation
+proceeds.
+
+** Grep
+
+---
+*** Grep commands will now use GNU grep's '--null' option if
+available, which allows distinguishing the filename from contents if
+they contain colons. This can be controlled by the new custom option
+'grep-use-null-filename-separator'.
+
+---
+*** The grep/rgrep/lgrep functions will now ask about saving files
+before running. This is controlled by the 'grep-save-buffers'
+variable.
+
+** Edebug
+
+---
+*** Edebug can be prevented from pausing 1 second after reaching a
+breakpoint (e.g. with "f" and "o") by customizing the new option
+'edebug-sit-on-break'.
+
++++
+*** New customizable option 'edebug-max-depth'.
+This allows to enlarge the maximum recursion depth when instrumenting
+code.
+
+** Eshell
+
+---
+*** 'eshell-input-filter's value is now a named function
+'eshell-input-filter-default', and has a new custom option
+'eshell-input-filter-initial-space' to ignore adding commands prefixed
+with blank space to eshell history.
+
+** EUDC
+
+---
+*** Backward compatibility support for BBDB versions less than 3
+(i.e., BBDB 2.x) is deprecated and will likely be removed in the next
+major release of Emacs. Users of BBDB 2.x should plan to upgrade to
+BBDB 3.x.
+
+** eww
+
++++
+*** New 'M-RET' command for opening a link at point in a new eww buffer.
+
++++
+*** A new 's' command for switching to another eww buffer via the minibuffer.
+
+---
+*** The 'o' command ('shr-save-contents') has moved to 'O' to avoid collision
+with the 'o' command from 'image-map'.
+
++++
+*** A new command 'C' ('eww-toggle-colors') can be used to toggle
+whether to use the HTML-specified colors or not. The user can also
+customize the 'shr-use-colors' variable.
+
+---
+*** Images that are being loaded are now marked with gray
+"placeholder" images of the size specified by the HTML. They are then
+replaced by the real images asynchronously, which will also now
+respect width/height HTML specs (unless they specify widths/heights
+bigger than the current window).
+
+---
+*** The 'w' command on links is now 'shr-maybe-probe-and-copy-url'.
+'shr-copy-url' now only copies the url at point; users who wish to
+avoid accidentally accessing remote links may rebind 'w' and 'u' in
+'eww-link-keymap' to it.
+
+** Ido
+
+---
+*** The commands 'find-alternate-file-other-window',
+'dired-other-window', 'dired-other-frame', and
+'display-buffer-other-window' are now remapped to Ido equivalents if
+Ido mode is active.
+
+** Images
+
++++
+*** Images are automatically scaled before displaying based on the
+'image-scaling-factor' variable (if Emacs supports scaling the images
+in question).
+
++++
+*** It's now possible to specify aspect-ratio preserving combinations
+of :width/:max-height and :height/:max-width keywords. In either
+case, the "max" keywords win. (Previously some combinations would,
+depending on the aspect ratio of the image, just be ignored and in
+other instances this would lead to the aspect ratio not being
+preserved.)
+
++++
+*** Images inserted with 'insert-image' and related functions get a
+keymap put into the text properties (or overlays) that span the
+image. This keymap binds keystrokes for manipulating size and
+rotation, as well as saving the image to a file. These commands are
+also available in 'image-mode'.
+
++++
+*** A new library for creating and manipulating SVG images has been
+added. See the "(elisp) SVG Images" section in the ELisp reference
+manual for details.
+
++++
+*** New setf-able function to access and set image parameters is
+provided: 'image-property'.
+
+---
+*** New commands 'image-scroll-left' and 'image-scroll-right'
+for 'image-mode' that complement 'image-scroll-up' and
+'image-scroll-down': they have the same prefix arg behavior and stop
+at image boundaries.
+
+** Image-Dired
+
+---
+*** Now provides a minor mode 'image-dired-minor-mode' which replaces
+the function 'image-dired-setup-dired-keybindings'.
+
+---
+*** Thumbnail generation is now asynchronous.
+The number of concurrent processes is limited by the variable
+'image-dired-thumb-job-limit'.
+
+---
+*** 'image-dired-thumbnail-storage' has a new option 'standard-large'
+for generating 256x256 thumbnails according to the Thumbnail Managing
+Standard.
+
+---
+*** Inherits movement keys from 'image-mode' for viewing full images.
+This includes the usual char, line, and page movement commands.
+
+---
+*** All the -options types have been changed to argument lists
+instead of shell command strings. This change affects
+'image-dired-cmd-create-thumbnail-options',
+'image-dired-cmd-create-temp-image-options',
+'image-dired-cmd-rotate-thumbnail-options',
+'image-dired-cmd-rotate-original-options',
+'image-dired-cmd-write-exif-data-options',
+'image-dired-cmd-read-exif-data-options', and introduces
+'image-dired-cmd-pngnq-options', 'image-dired-cmd-pngcrush-options',
+'image-dired-cmd-create-standard-thumbnail-options'.
+
+---
+*** Recognizes more tools by default, including pngnq-s9 and OptiPNG.
+
+---
+*** 'find-file' and related commands now work on thumbnails and
+displayed images, providing a default argument of the original file name
+via an addition to 'file-name-at-point-functions'.
+
+---
+** The default 'Info-default-directory-list' no longer checks some obsolete
+directory suffixes (gnu, gnu/lib, gnu/lib/emacs, emacs, lib, lib/emacs)
+when searching for info directories.
+
++++
+** The commands that add ChangeLog entries now prefer a VCS root directory
+for the ChangeLog file, if none already exists. Customize
+'change-log-directory-files' to nil for the old behavior.
+
+---
+** Support for non-string values of 'time-stamp-format' has been removed.
+
+** Message
+
+---
+*** 'message-use-idna' now defaults to t (because Emacs comes with
+built-in IDNA support now).
+
+---
+*** When sending HTML messages with embedded images, and you have
+exiftool installed, and you rotate images with EXIF data (i.e.,
+JPEGs), the rotational information will be inserted into the outgoing
+image in the message. (The original image will not have its
+orientation affected.)
+
+---
+*** The 'message-valid-fqdn-regexp' variable has been removed, since
+there are now top-level domains added all the time. Message will no
+longer warn about sending emails to top-level domains it hasn't heard
+about.
+
+---
+*** 'message-beginning-of-line' (bound to 'C-a') understands folded headers.
+In 'visual-line-mode' it will look for the true beginning of a header
+while in non-'visual-line-mode' it will move the point to the indented
+header's value.
+
+** Package
+
++++
+*** The new variable 'package-gnupghome-dir' has been added to control
+where the GnuPG home directory (used for signature verification) is
+located and whether GnuPG's option '--homedir' is used or not.
+
+---
+*** Deleting a package no longer respects 'delete-by-moving-to-trash'.
+
+** Tramp
+
++++
+*** The method part of remote file names is mandatory now.
+A valid remote file name starts with "/method:host:" or
+"/method:user@host:".
+
++++
+*** The new pseudo method "-" is a marker for the default method.
+"/-::" is the shortest remote file name then.
+
++++
+*** The command 'tramp-change-syntax' allows to choose an alternative
+remote file name syntax.
+
++++
+*** New connection method "sg", which supports editing files under a
+different group ID.
+
++++
+*** New connection method "doas" for OpenBSD hosts.
+
++++
+*** New connection method "gdrive", which allows to access Google
+Drive onsite repositories.
+
++++
+*** Gateway methods in Tramp have been removed.
+Instead, the Tramp manual documents how to configure ssh and PuTTY
+accordingly.
+
++++
+*** Setting the "ENV" environment variable in
+'tramp-remote-process-environment' enables reading of shell
+initialization files.
+
+---
+*** Tramp is able now to send SIGINT to remote asynchronous processes.
+
+---
+*** Variable 'tramp-completion-mode' is obsoleted.
+
+---
+** 'auto-revert-use-notify' is set back to t in 'global-auto-revert-mode'.
+
+** JS mode
+
+---
+*** JS mode now sets 'comment-multi-line' to t.
+
+---
+*** New variable 'js-indent-align-list-continuation', when set to nil,
+will not align continuations of bracketed lists, but will indent them
+by the fixed width 'js-indent-level'.
+
+** CSS mode
+
+---
+*** Support for completing attribute values, at-rules, bang-rules,
+HTML tags, classes and IDs using the 'completion-at-point' command.
+Completion candidates for HTML classes and IDs are retrieved from open
+HTML mode buffers.
+
+---
+*** CSS mode now binds 'C-h S' to a function that will show
+information about a CSS construct (an at-rule, property, pseudo-class,
+pseudo-element, with the default being guessed from context). By
+default the information is looked up on the Mozilla Developer Network,
+but this can be customized using 'css-lookup-url-format'.
+
+---
+*** CSS colors are fontified using the color they represent as the
+background. For instance, #ff0000 would be fontified with a red
+background.
+
++++
+** Emacs now supports character name escape sequences in character and
+string literals. The syntax variants '\N{character name}' and
+'\N{U+code}' are supported.
+
++++
+** Prog mode has some support for multi-mode indentation.
+This allows better indentation support in modes that support multiple
+programming languages in the same buffer, like literate programming
+environments or ANTLR programs with embedded Python code.
+
+A major mode can provide indentation context for a sub-mode. To
+support this, modes should use 'prog-first-column' instead of a
+literal zero and avoid calling 'widen' in their indentation functions.
+See the node "(elisp) Mode-Specific Indent" in the ELisp manual for
+more details.
+
+** ERC
+
+---
+*** New variable 'erc-default-port-tls' used to connect to TLS IRC
+servers.
+
+** URL
+
++++
+*** The new function 'url-cookie-delete-cookie' can be used to
+programmatically delete all cookies, or cookies from a specific
+domain.
+
++++
+*** 'url-retrieve-synchronously' now takes an optional timeout parameter.
+
+---
+*** The URL package now supports HTTPS over proxies supporting CONNECT.
+
++++
+*** 'url-user-agent' now defaults to 'default', and the User-Agent
+string is computed dynamically based on 'url-privacy-level'.
+
+** VC and related modes
+
++++
+*** 'vc-dir-mode' now binds 'vc-log-outgoing' to 'O'; and has various
+branch-related commands on a keymap bound to 'B'.
+
++++
+*** 'vc-region-history' is now bound to 'C-x v h', replacing the older
+'vc-insert-headers' binding.
+
+** CC mode
+
+---
+*** Opening a .h file will turn C or C++ mode depending on language used.
+This is done with the help of the 'c-or-c++-mode' function, which
+analyzes buffer contents to infer whether it's a C or C++ source file.
+
+---
+** New option 'cpp-message-min-time-interval' to allow user control
+of progress messages in cpp.el.
+
+---
+** New DNS mode command 'dns-mode-ipv6-to-nibbles' to convert IPv6 addresses
+to a format suitable for reverse lookup zone files.
+
+** Ispell
+
++++
+*** Enchant is now supported as a spell-checker.
+
+Enchant is a meta-spell-checker that uses providers such as Hunspell
+to do the actual checking. With it, users can use spell-checkers not
+directly supported by Emacs, such as Voikko, Hspell and AppleSpell,
+more easily share personal word-lists with other programs, and
+configure different spelling-checkers for different languages.
+(Version 2.1.0 or later of Enchant is required.)
+
+** Flymake
+
++++
+*** Flymake has been completely redesigned
+
+Flymake now annotates arbitrary buffer regions, not just lines. It
+supports arbitrary diagnostic types, not just errors and warnings (see
+variable 'flymake-diagnostic-types-alist').
+
+It also supports multiple simultaneous backends, meaning that you can
+check your buffer from different perspectives (see variable
+'flymake-diagnostic-functions'). Backends for Emacs Lisp mode are
+provided.
+
+The old Flymake behavior is preserved in the so-called "legacy
+backend", which has been updated to benefit from the new UI features.
+
+** Term
+
+---
+*** `term-char-mode' now makes its buffer read-only.
+
+The buffer is made read-only to prevent changes from being made by
+anything other than the process filter; and movements of point away
+from the process mark are counter-acted so that the cursor is in the
+correct position after each command. This is needed to avoid states
+which are inconsistent with the state of the terminal understood by
+the inferior process.
+
+New user options `term-char-mode-buffer-read-only' and
+`term-char-mode-point-at-process-mark' control these behaviors, and
+are non-nil by default. Customize these options to nil if you want
+the previous behavior.
+
+** Xref
+
++++
+*** When an *xref* buffer is needed, 'TAB' quits and jumps to an xref.
+
+A new command 'xref-quit-and-goto-xref', bound to 'TAB' in *xref*
+buffers, quits the window before jumping to the destination. In many
+situations, the intended window configuration is restored, just as if
+the *xref* buffer hadn't been necessary in the first place.
+
+\f
+* New Modes and Packages in Emacs 26.1
+
+---
+** New Elisp data-structure library 'radix-tree'.
+
+---
+** New library 'xdg' with utilities for some XDG standards and specs.
+
+** HTML
+
++++
+*** A new submode of 'html-mode', 'mhtml-mode', is now the default
+mode for *.html files. This mode handles indentation,
+fontification, and commenting for embedded JavaScript and CSS.
+
+---
+** New mode 'conf-toml-mode' is a sub-mode of 'conf-mode', specialized
+for editing TOML files.
+
+---
+** New mode 'conf-desktop-mode' is a sub-mode of 'conf-unix-mode',
+specialized for editing freedesktop.org desktop entries.
+
+---
+** New minor mode 'pixel-scroll-mode' provides smooth pixel-level scrolling.
+
+---
+** New major mode 'less-css-mode' (a minor variant of 'css-mode') for
+editing Less files.
+
+\f
+* Incompatible Lisp Changes in Emacs 26.1
+
+---
+** 'password-data' is now a hash-table so that 'password-read' can use
+any object for the 'key' argument.
+
++++
+** Command 'dired-mark-extension' now automatically prepends a '.' to the
+extension when not present. The new command 'dired-mark-suffix' behaves
+similarly but it doesn't prepend a '.'.
+
++++
+** Certain cond/pcase/cl-case forms are now compiled using a faster jump
+table implementation. This uses a new bytecode op 'switch', which
+isn't compatible with previous Emacs versions. This functionality can
+be disabled by setting 'byte-compile-cond-use-jump-table' to nil.
+
++++
+** If 'comment-auto-fill-only-comments' is non-nil, 'auto-fill-function'
+is now called only if either no comment syntax is defined for the
+current buffer or the self-insertion takes place within a comment.
+
+---
+** The alist 'ucs-names' is now a hash table.
+
+---
+** 'if-let' and 'when-let' are subsumed by 'if-let*' and 'when-let*'.
+The incumbent 'if-let' and 'when-let' are now marked obsolete.
+'if-let*' and 'when-let*' do not accept the single tuple special case.
+New macro 'and-let*' is an implementation of the Scheme SRFI-2 syntax
+of the same name. 'if-let*' and 'when-let*' now accept the same
+binding syntax as 'and-let*'.
+
+---
+** 'C-up', 'C-down', 'C-left' and 'C-right' are now defined in term
+mode to send the same escape sequences that xterm does. This makes
+things like 'forward-word' in readline work.
+
+---
+** Customizable variable 'query-replace-from-to-separator'
+now doesn't propertize the string value of the separator.
+Instead, text properties are added by 'query-replace-read-from'.
+Additionally, the new nil value restores pre-24.5 behavior
+of not providing replacement pairs via the history.
+
+---
+** Some obsolete functions, variables, and faces have been removed:
+
+*** 'make-variable-frame-local'. Variables cannot be frame-local any more.
+
+*** From subr.el: 'window-dot', 'set-window-dot', 'read-input',
+'show-buffer', 'eval-current-buffer', 'string-to-int'.
+
+*** 'icomplete-prospects-length'.
+
+*** All the default-FOO variables that hold the default value of the
+FOO variable. Use 'default-value' and 'setq-default' to access and
+change FOO, respectively. The exhaustive list of removed variables is:
+'default-mode-line-format', 'default-header-line-format',
+'default-line-spacing', 'default-abbrev-mode', 'default-ctl-arrow',
+'default-truncate-lines', 'default-left-margin', 'default-tab-width',
+'default-case-fold-search', 'default-left-margin-width',
+'default-right-margin-width', 'default-left-fringe-width',
+'default-right-fringe-width', 'default-fringes-outside-margins',
+'default-scroll-bar-width', 'default-vertical-scroll-bar',
+'default-indicate-empty-lines', 'default-indicate-buffer-boundaries',
+'default-fringe-indicator-alist', 'default-fringe-cursor-alist',
+'default-scroll-up-aggressively', 'default-scroll-down-aggressively',
+'default-fill-column', 'default-cursor-type',
+'default-cursor-in-non-selected-windows',
+'default-buffer-file-coding-system', 'default-major-mode', and
+'default-enable-multibyte-characters'.
+
+*** Many variables obsoleted in 22.1 referring to face symbols.
+
++++
+** The variable 'text-quoting-style' is now a customizable option. It
+controls whether to and how to translate ASCII quotes in messages and
+help output. Its possible values and their semantics remain unchanged
+from Emacs 25. In particular, when this variable's value is 'grave',
+all quotes in formats are output as-is.
+
+---
+** Functions like 'check-declare-file' and 'check-declare-directory'
+now generate less chatter and more-compact diagnostics. The auxiliary
+function 'check-declare-errmsg' has been removed.
+
++++
+** The regular expression character class '[:blank:]' now matches
+Unicode horizontal whitespace as defined in the Unicode Technical
+Standard #18. If you only want to match space and tab, use '[ \t]'
+instead.
+
++++
+** 'min' and 'max' no longer round their results.
+Formerly, they returned a floating-point value if any argument was
+floating-point, which was sometimes numerically incorrect. For
+example, on a 64-bit host (max 1e16 10000000000000001) now returns its
+second argument instead of its first.
+
++++
+** The variable 'old-style-backquotes' has been made internal and
+renamed to 'lread--old-style-backquotes'. No user code should use
+this variable.
+
+---
+** To avoid confusion caused by "smart quotes", the reader no longer
+accepts Lisp symbols which begin with the following quotation
+characters: ‘’‛“”‟〞＂＇, unless they are escaped with backslash.
+
++++
+** 'default-file-name-coding-system' now defaults to a coding system
+that does not process CRLF. For example, it defaults to 'utf-8-unix'
+instead of to 'utf-8'. Before this change, Emacs would sometimes
+mishandle file names containing these control characters.
+
++++
+** 'file-attributes', 'file-symlink-p' and 'make-symbolic-link' no
+longer quietly mutate the target of a local symbolic link, so that
+Emacs can access and copy them reliably regardless of their contents.
+The following changes are involved.
+
+---
+*** 'file-attributes' and 'file-symlink-p' no longer prepend "/:" to
+symbolic links whose targets begin with "/" and contain ":". For
+example, if a symbolic link "x" has a target "/y:z:", '(file-symlink-p
+"x")' now returns "/y:z:" rather than "/:/y:z:".
+
+---
+*** 'make-symbolic-link' no longer looks for file name handlers of
+target when creating a symbolic link. For example,
+'(make-symbolic-link "/y:z:" "x")' now creates a symbolic link to
+"/y:z:" instead of failing.
+
++++
+*** 'make-symbolic-link' removes the remote part of a link target if
+target and newname have the same remote part. For example,
+'(make-symbolic-link "/x:y:a" "/x:y:b")' creates a link with the
+literal string "a"; and '(make-symbolic-link "/x:y:a" "/x:z:b")'
+creates a link with the literal string "/x:y:a" instead of failing.
+
++++
+*** 'make-symbolic-link' now expands a link target with leading "~"
+only when the optional third arg is an integer, as when invoked
+interactively. For example, '(make-symbolic-link "~y" "x")' now
+creates a link with target the literal string "~y"; to get the old
+behavior, use '(make-symbolic-link (expand-file-name "~y") "x")'. To
+avoid this expansion in interactive use, you can now prefix the link
+target with "/:". For example, '(make-symbolic-link "/:~y" "x" 1)'
+now creates a link to literal "~y".
+
++++
+** 'file-truename' returns a quoted file name if the target of a
+symbolic link has remote file name syntax.
+
++++
+** Module functions are now implemented slightly differently; in
+particular, the function 'internal--module-call' has been removed.
+Code that depends on undocumented internals of the module system might
+break.
+
+---
+** The argument LOCKNAME of 'write-region' is propagated to file name
+handlers now.
+
+---
+** When built against recent versions of GTK+, Emacs always uses
+gtk_window_move for moving frames and ignores the value of the
+variable 'x-gtk-use-window-move'. The variable is now obsolete.
+
++++
+** Several functions that create or rename files now treat their
+destination argument specially only when it is a directory name, i.e.,
+when it ends in '/' on GNU and other POSIX-like systems. When the
+destination argument D of one of these functions is an existing
+directory and the intent is to act on an entry in that directory, D
+should now be a directory name. For example, (rename-file "e" "f/")
+renames to 'f/e'. Although this formerly happened sometimes even when
+D was not a directory name, as in (rename-file "e" "f") where 'f'
+happened to be a directory, the old behavior often contradicted the
+documentation and had inherent races that led to security holes. A
+call like (rename-file C D) that used the old, undocumented behavior
+can be written as (rename-file C (file-name-as-directory D)), a
+formulation portable to both older and newer versions of Emacs.
+Affected functions include 'add-name-to-file', 'copy-directory',
+'copy-file', 'format-write-file', 'gnus-copy-file',
+'make-symbolic-link', 'rename-file', 'thumbs-rename-images', and
+'write-file'.
+
+---
+** The list returned by 'overlays-at' is now in decreasing priority order.
+The documentation of this function always said the order should be
+that of decreasing priority, if the 2nd argument of the function is
+non-nil, but the code returned the list in the increasing order of
+priority instead. Now the code does what the documentation says it
+should do.
+
++++
+** 'format' now avoids allocating a new string in more cases.
+'format' was previously documented to return a newly-allocated string,
+but this documentation was not correct, as (eq x (format x)) returned
+t when x was the empty string. 'format' is no longer documented to
+return a newly-allocated string, and the implementation now takes
+advantage of the doc change to avoid making copies of strings in
+common cases like (format "foo") and (format "%s" "foo").
+
+---
+** The function 'eldoc-message' now accepts a single argument.
+Programs that called it with multiple arguments before should pass
+them through 'format' first. Even that is discouraged: for ElDoc
+support, you should set 'eldoc-documentation-function' instead of
+calling 'eldoc-message' directly.
+
+---
+** Using '&rest' or '&optional' incorrectly is now an error.
+For example giving '&optional' without a following variable, or
+passing '&optional' multiple times:
+
+ (defun foo (&optional &rest x))
+ (defun bar (&optional &optional x))
+
+Previously, Emacs would just ignore the extra keyword, or give
+incorrect results in certain cases.
+
+---
+** The pinentry.el library has been removed.
+That package (and the corresponding change in GnuPG and pinentry)
+was intended to provide a way to input passphrase through Emacs with
+GnuPG 2.0. However, the change to support that was only implemented
+in GnuPG >= 2.1 and didn't get backported to GnuPG 2.0. And with
+GnuPG 2.1 and later, pinentry.el is not needed at all. So the
+library was useless, and we removed it. GnuPG 2.0 is no longer
+supported by the upstream project.
+
+To adapt to the change, you may need to set 'epa-pinentry-mode' to the
+symbol 'loopback'.
+
++Note that previously, it was said that passphrase input through
++minibuffer would be much less secure than other graphical pinentry
++programs. However, these days the difference is insignificant: the
++'read-password' function sufficiently protects input from leakage to
++message logs. Emacs still doesn't use secure memory to protect
++passphrases, but it was also removed from other pinentry programs as
++the attack is unrealistic on modern computer systems which don't
++utilize swap memory usually.
++
+\f
+* Lisp Changes in Emacs 26.1
+
++++
+** The function 'assoc' now takes an optional third argument TESTFN.
+This argument, when non-nil, is used for comparison instead of
+'equal'.
+
++++
+** New optional argument TESTFN in 'alist-get', 'map-elt' and 'map-put'.
+If non-nil, the argument specifies a function to use for comparison,
+instead of, respectively, 'assq' and 'eql'.
+
++++
+** New function 'seq-set-equal-p' to check if SEQUENCE1 and SEQUENCE2
+contain the same elements, regardless of the order.
+
++++
+** The new function 'mapbacktrace' applies a function to all frames of
+the current stack trace.
+
++++
+** The new function 'file-name-case-insensitive-p' tests whether a
+given file is on a case-insensitive filesystem.
+
++++
+** Several accessors for the value returned by 'file-attributes'
+have been added. They are: 'file-attribute-type',
+'file-attribute-link-number', 'file-attribute-user-id',
+'file-attribute-group-id', 'file-attribute-access-time',
+'file-attribute-modification-time',
+'file-attribute-status-change-time', 'file-attribute-size',
+'file-attribute-modes', 'file-attribute-inode-number',
+'file-attribute-device-number' and 'file-attribute-collect'.
+
++++
+** The new function 'buffer-hash' computes a fast, non-consing hash of
+a buffer's contents.
+
++++
+** 'interrupt-process' now consults the list 'interrupt-process-functions',
+to determine which function has to be called in order to deliver the
+SIGINT signal. This allows Tramp to send the SIGINT signal to remote
+asynchronous processes. The hitherto existing implementation has been
+moved to 'internal-default-interrupt-process'.
+
++++
+** The new function 'read-multiple-choice' prompts for multiple-choice
+questions, with a handy way to display help texts.
+
+---
+** 'comment-indent-function' values may now return a cons to specify a
+range of indentation.
+
++++
+** New optional argument TEXT in 'make-temp-file'.
+
+---
+** New function 'define-symbol-prop'.
+
++++
+** New function 'secure-hash-algorithms' to list the algorithms that
+'secure-hash' supports.
+See the node "(elisp) Checksum/Hash" in the ELisp manual for details.
+
++++
+** Emacs now exposes the GnuTLS cryptographic API with the functions
+'gnutls-macs' and 'gnutls-hash-mac'; 'gnutls-digests' and
+'gnutls-hash-digest'; 'gnutls-ciphers' and 'gnutls-symmetric-encrypt'
+and 'gnutls-symmetric-decrypt'.
+See the node "(elisp) GnuTLS Cryptography" in the ELisp manual for details.
+
++++
+** The function 'gnutls-available-p' now returns a list of capabilities
+supported by the GnuTLS library used by Emacs.
+
++++
+** Emacs now supports records for user-defined types, via the new
+functions 'make-record', 'record', and 'recordp'. Records are now
+used internally to represent cl-defstruct and defclass instances, for
+example.
+
+If your program defines new record types, you should use
+package-naming conventions for naming those types. This is so any
+potential conflicts with other types are avoided.
+
++++
+** 'save-some-buffers' now uses 'save-some-buffers-default-predicate'
+to decide which buffers to ask about, if the PRED argument is nil.
+The default value of 'save-some-buffers-default-predicate' is nil,
+which means ask about all file-visiting buffers.
+
+---
+** string-(to|as|make)-(uni|multi)byte are now declared obsolete.
+
++++
+** New variable 'while-no-input-ignore-events' which allow
+setting which special events 'while-no-input' should ignore.
+It is a list of symbols.
+
+---
+** New function 'undo-amalgamate-change-group' to get rid of
+undo-boundaries between two states.
+
+---
+** New var 'definition-prefixes' is a hash table mapping prefixes to
+the files where corresponding definitions can be found. This can be
+used to fetch definitions that are not yet loaded, for example for
+'C-h f'.
+
+---
+** New var 'syntax-ppss-table' to control the syntax-table used in
+'syntax-ppss'.
+
++++
+** 'define-derived-mode' can now specify an :after-hook form, which
+gets evaluated after the new mode's hook has run. This can be used to
+incorporate configuration changes made in the mode hook into the
+mode's setup.
+
+---
+** Autoload files can be generated without timestamps,
+by setting 'autoload-timestamps' to nil.
+FIXME As an experiment, nil is the current default.
+If no insurmountable problems before next release, it can stay that way.
+
+---
+** 'gnutls-boot' now takes a parameter ':complete-negotiation' that
+says that negotiation should complete even on non-blocking sockets.
+
+---
+** There is now a new variable 'flyspell-sort-corrections-function'
+that allows changing the way corrections are sorted.
+
+---
+** The new command 'fortune-message' has been added, which displays
+fortunes in the echo area.
+
++++
+** New function 'func-arity' returns information about the argument list
+of an arbitrary function. This generalizes 'subr-arity' for functions
+that are not built-in primitives. We recommend using this new
+function instead of 'subr-arity'.
+
+---
+** New function 'region-bounds' can be used in the interactive spec
+to provide region boundaries (for rectangular regions more than one)
+to an interactively callable function as a single argument instead of
+two separate arguments 'region-beginning' and 'region-end'.
+
++++
+** 'parse-partial-sexp' state has a new element. Element 10 is
+non-nil when the last character scanned might be the first character
+of a two character construct, i.e., a comment delimiter or escaped
+character. Its value is the syntax of that last character.
+
++++
+** 'parse-partial-sexp's state, element 9, has now been confirmed as
+permanent and documented, and may be used by Lisp programs. Its value
+is a list of currently open parenthesis positions, starting with the
+outermost parenthesis.
+
+---
+** 'read-color' will now display the color names using the color itself
+as the background color.
+
+---
+** The function 'redirect-debugging-output' now works on platforms
+other than GNU/Linux.
+
++++
+** The new function 'string-version-lessp' compares strings by
+interpreting consecutive runs of numerical characters as numbers, and
+compares their numerical values. According to this predicate,
+"foo2.png" is smaller than "foo12.png".
+
+---
+** Numeric comparisons and 'logb' no longer return incorrect answers
+due to internal rounding errors. For example, '(< most-positive-fixnum
+(+ 1.0 most-positive-fixnum))' now correctly returns t on 64-bit hosts.
+
+---
+** The functions 'ffloor', 'fceiling', 'ftruncate' and 'fround' now
+accept only floating-point arguments, as per their documentation.
+Formerly, they quietly accepted integer arguments and sometimes
+returned nonsensical answers, e.g., '(< N (ffloor N))' could return t.
+
+---
+** On hosts like GNU/Linux x86-64 where a 'long double' fraction
+contains at least EMACS_INT_WIDTH - 3 bits, 'format' no longer returns
+incorrect answers due to internal rounding errors when formatting
+Emacs integers with '%e', '%f', or '%g' conversions. For example, on
+these hosts '(eql N (string-to-number (format "%.0f" N)))' now returns
+t for all Emacs integers N.
+
+---
+** Calls that accept floating-point integers (for use on hosts with
+limited integer range) now signal an error if arguments are not
+integral. For example '(decode-char 'ascii 0.5)' now signals an error.
+
++++
+** The new function 'char-from-name' converts a Unicode name string
+to the corresponding character code.
+
++++
+** New functions 'sxhash-eq' and 'sxhash-eql' return hash codes of a
+Lisp object suitable for use with 'eq' and 'eql' correspondingly. If
+two objects are 'eq' ('eql'), then the result of 'sxhash-eq'
+('sxhash-eql') on them will be the same.
+
++++
+** Function 'sxhash' has been renamed to 'sxhash-equal' for
+consistency with the new functions. For compatibility, 'sxhash'
+remains as an alias to 'sxhash-equal'.
+
++++
+** 'make-hash-table' now defaults to a rehash threshold of 0.8125
+instead of 0.8, to avoid rounding glitches.
+
++++
+** New function 'add-variable-watcher' can be used to call a function
+when a symbol's value is changed. This is used to implement the new
+debugger command 'debug-on-variable-change'.
+
++++
+** Time conversion functions that accept a time zone rule argument now
+allow it to be OFFSET or a list (OFFSET ABBR), where the integer
+OFFSET is a count of seconds east of Universal Time, and the string
+ABBR is a time zone abbreviation. The affected functions are
+'current-time-string', 'current-time-zone', 'decode-time',
+'format-time-string', and 'set-time-zone-rule'.
+
++++
+** 'format-time-string' now formats '%q' to the calendar quarter.
+
++++
+** New built-in function 'mapcan'.
+It avoids unnecessary consing (and garbage collection).
+
++++
+** 'car' and 'cdr' compositions 'cXXXr' and 'cXXXXr' are now part of Elisp.
+
++++
+** 'gensym' is now part of Elisp.
+
+---
+** Low-level list functions like 'length' and 'member' now do a better
+job of signaling list cycles instead of looping indefinitely.
+
++++
+** The new functions 'make-nearby-temp-file' and 'temporary-file-directory'
+can be used for creation of temporary files on remote or mounted directories.
+
++++
+** On GNU platforms when operating on a local file, 'file-attributes'
+no longer suffers from a race when called while another process is
+altering the filesystem. On non-GNU platforms 'file-attributes'
+attempts to detect the race, and returns nil if it does so.
+
++++
+** The new function 'file-local-name' can be used to specify arguments
+of remote processes.
+
++++
+** The new functions 'file-name-quote', 'file-name-unquote' and
+'file-name-quoted-p' can be used to quote / unquote file names with
+the prefix "/:".
+
++++
+** The new error 'file-missing', a subcategory of 'file-error', is now
+signaled instead of 'file-error' if a file operation acts on a file
+that does not exist.
+
++++
+** The function 'delete-directory' no longer signals an error when
+operating recursively and when some other process deletes the directory
+or its files before 'delete-directory' gets to them.
+
++++
+** New error type 'user-search-failed' like 'search-failed' but
+avoids debugger like 'user-error'.
+
++++
+** The function 'line-number-at-pos' now takes a second optional
+argument 'absolute'. If this parameter is nil, the default, this
+function keeps on returning the line number taking potential narrowing
+into account. If this parameter is non-nil, the function ignores
+narrowing and returns the absolute line number.
+
+---
+** The function 'color-distance' now takes a second optional argument
+'metric'. When non-nil, it should be a function of two arguments that
+accepts two colors and returns a number.
+
+** Changes in Frame and Window Handling
+
++++
+*** Resizing a frame no longer runs 'window-configuration-change-hook'.
+'window-size-change-functions' should be used instead.
+
++++
+*** The new function 'frame-size-changed-p' can tell whether a frame has
+been resized since the last time 'window-size-change-functions' has been
+run.
+
++++
+*** The function 'frame-geometry' now also returns the width of a
+frame's outer border.
+
++++
+*** New frame parameters and changed semantics for older ones:
+
++++
+**** 'z-group' positions a frame above or below all others.
+
++++
+**** 'min-width' and 'min-height' specify the absolute minimum size of a
+frame.
+
++++
+**** 'parent-frame' makes a frame the child frame of another Emacs
+frame. The section "(elisp) Child Frames" in the ELisp manual
+describes the intrinsics of that relationship.
+
++++
+**** 'delete-before' triggers deletion of one frame before that of
+another.
+
++++
+**** 'mouse-wheel-frame' specifies another frame whose windows shall be
+scrolled instead.
+
++++
+**** 'no-other-frame' has 'next-frame' and 'previous-frame' skip this
+frame.
+
++++
+**** 'skip-taskbar' removes a frame's icon from the taskbar and has
+'Alt-<TAB>' skip this frame.
+
++++
+**** 'no-focus-on-map' avoids that a frame gets input focus when mapped.
+
++++
+**** 'no-accept-focus' means that a frame does not want to get input
+focus via the mouse.
+
++++
+**** 'undecorated' removes the window manager decorations from a frame.
+
++++
+**** 'override-redirect' tells the window manager to disregard this
+frame.
+
++++
+**** 'width' and 'height' allow to specify pixel values and ratios now.
+
++++
+**** 'left' and 'top' allow to specify ratios now.
+
++++
+**** 'keep-ratio' preserves size and position of child frames when their
+parent frame is resized.
+
++++
+**** 'no-special-glyphs' suppresses display of truncation and
+continuation glyphs in a frame.
+
++++
+**** 'auto-hide-function' and 'minibuffer-exit' handle auto hiding of
+frames and exiting from minibuffer individually.
+
++++
+**** 'fit-frame-to-buffer-margins' and 'fit-frame-to-buffer-sizes'
+handle fitting a frame to its buffer individually.
+
++++
+**** 'drag-internal-border', 'drag-with-header-line',
+'drag-with-mode-line', 'snap-width', 'top-visible' and 'bottom-visible'
+allow to drag and resize frames with the mouse.
+
++++
+**** 'minibuffer' is now set to the default minibuffer window when
+initially specified as nil and is not reset to nil when initially
+specifying a minibuffer window.
+
+*** The new function 'frame-list-z-order' returns a list of all frames
+in Z (stacking) order.
+
++++
+*** The function 'x-focus-frame' optionally tries to not activate its
+frame.
+
++++
+*** The variable 'focus-follows-mouse' has a third meaningful value
+'auto-raise' to indicate that the window manager automatically raises a
+frame when the mouse pointer enters it.
+
++++
+*** The new function 'frame-restack' puts a frame above or below
+another on the display.
+
++++
+*** The new face 'internal-border' specifies the background of a frame's
+internal border.
+
++++
+*** The NORECORD argument of 'select-window' now has a meaningful value
+'mark-for-redisplay' which is like any other non-nil value but marks
+WINDOW for redisplay.
+
++++
+*** Support for side windows is now official. The display action
+function 'display-buffer-in-side-window' will display its buffer in a
+side window. Functions for toggling all side windows on a frame,
+changing and reversing the layout of side windows and returning the
+main (major non-side) window of a frame are provided. For details
+consult the section "(elisp) Side Windows" in the ELisp manual.
+
++++
+*** Support for atomic windows - rectangular compositions of windows
+treated by 'split-window', 'delete-window' and 'delete-other-windows'
+like a single live window - is now official. For details consult the
+section "(elisp) Atomic Windows" in the ELisp manual.
+
++++
+*** New 'display-buffer' alist entry 'window-parameters' allows to
+assign window parameters to the window used for displaying the buffer.
+
++++
+*** New function 'display-buffer-reuse-mode-window' is an action function
+suitable for use in 'display-buffer-alist'. For example, to avoid
+creating a new window when opening man pages when there's already one,
+use
+
+(add-to-list 'display-buffer-alist
+ '("\\`\\*Man .*\\*\\'" .
+ (display-buffer-reuse-mode-window
+ (inhibit-same-window . nil)
+ (mode . Man-mode))))
+
++++
+*** New window parameter 'no-delete-other-windows' prevents that
+its window gets deleted by 'delete-other-windows'.
+
++++
+*** New window parameters 'mode-line-format' and 'header-line-format'
+allow to override the buffer-local formats for this window.
+
++++
+*** New command 'window-swap-states' swaps the states of two live
+windows.
+
++++
+*** New functions 'window-pixel-width-before-size-change' and
+'window-pixel-height-before-size-change' support detecting which
+window changed size when 'window-size-change-functions' are run.
+
++++
+*** The new function 'window-lines-pixel-dimensions' returns the pixel
+dimensions of a window's text lines.
+
++++
+*** The new function 'window-largest-empty-rectangle' returns the
+dimensions of the largest rectangular area not occupying any text in a
+window's body.
+
++++
+*** The semantics of 'mouse-autoselect-window' has changed slightly.
+For details see the section "(elisp) Mouse Window Auto-selection" in
+the ELisp manual.
+
+---
+*** 'select-frame-by-name' now may return a frame on another display
+if it does not find a suitable one on the current display.
+
+---
+** 'tcl-auto-fill-mode' is now declared obsolete. Its functionality
+can be replicated simply by setting 'comment-auto-fill-only-comments'.
+
+** New pcase pattern 'rx' to match against an rx-style regular expression.
+For details, see the doc string of 'rx--pcase-macroexpander'.
+
+---
+** New functions to set region from secondary selection and vice versa.
+The new functions 'secondary-selection-to-region' and
+'secondary-selection-from-region' let you set the beginning and the
+end of the region from those of the secondary selection and vice
+versa.
+
+** New function 'lgstring-remove-glyph' can be used to modify a
+gstring returned by the underlying layout engine (e.g. m17n-flt,
+uniscribe).
+
+\f
+* Changes in Emacs 26.1 on Non-Free Operating Systems
+
++++
+** Intercepting hotkeys on Windows 7 and later now works better.
+The new keyboard hooking code properly grabs system hotkeys such as
+'Win-*' and 'Alt-TAB', in a way that Emacs can get at them before the
+system. This makes the 'w32-register-hot-key' functionality work
+again on all versions of MS-Windows starting with Windows 7. On
+Windows NT and later you can now register any hotkey combination. (On
+Windows 9X, the previous limitations, spelled out in the Emacs manual,
+still apply.)
+
+---
+** 'convert-standard-filename' no longer mirrors slashes on MS-Windows.
+Previously, on MS-Windows this function converted slash characters in
+file names into backslashes. It no longer does that. If your Lisp
+program used 'convert-standard-filename' to prepare file names to be
+passed to subprocesses (which is not the recommended usage of that
+function), you will now have to mirror slashes in your application
+code. One possible way is this:
+
+ (let ((start 0))
+ (while (string-match "/" file-name start)
+ (aset file-name (match-beginning 0) ?\\)
+ (setq start (match-end 0))))
+
+---
+** GUI sessions on MS-Windows now treat SIGINT like Posix platforms do.
+The effect of delivering a Ctrl-C (SIGINT) signal to a GUI Emacs on
+MS-Windows is now the same as on Posix platforms -- Emacs saves the
+session and exits. In particular, this will happen if you start
+emacs.exe from the Windows shell, then type Ctrl-C into that shell's
+window.
+
+---
+** 'signal-process' supports SIGTRAP on Windows XP and later.
+The 'kill' emulation on Windows now maps SIGTRAP to a call to the
+'DebugBreakProcess' API. This causes the receiving process to break
+execution and return control to the debugger. If no debugger is
+attached to the receiving process, the call is typically ignored.
+This is in contrast to the default action on POSIX Systems, where it
+causes the receiving process to terminate with a core dump if no
+debugger has been attached to it.
+
+---
+** 'set-mouse-position' and 'set-mouse-absolute-pixel-position' work
+on macOS.
+
+---
+** Emacs can now be run as a GUI application from the command line on
+macOS.
+
++++
+** 'ns-appearance' and 'ns-transparent-titlebar' change the appearance
+of frame decorations on macOS 10.9+.
+
+---
+** 'ns-use-thin-smoothing' enables thin font smoothing on macOS 10.8+.
+
+---
+** 'process-attributes' on Darwin systems now returns more information.
+
+---
+** Mousewheel and trackpad scrolling on macOS 10.7+ now behaves more
+like the macOS default. The new variables 'ns-mwheel-line-height',
+'ns-use-mwheel-acceleration' and 'ns-use-mwheel-momentum' can be used
+to customize the behavior.
+
+\f
+----------------------------------------------------------------------
+This file is part of GNU Emacs.
+
+GNU Emacs is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
+
+\f
+Local variables:
+coding: utf-8
+mode: outline
+paragraph-separate: "[ \f]*$"
+end:
projects / emacs.git / commitdiff