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

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This file is about changes in Emacs version 30.

See file HISTORY for a list of GNU Emacs versions and release dates.
See files NEWS.29, NEWS.28, ..., 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 relevant manuals in doc/ have been updated.
--- means no change in the manuals is needed.
When you add a new item, use the appropriate mark if you are sure it
applies, and please also update docstrings as needed.

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* Installation Changes in Emacs 30.1

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* Startup Changes in Emacs 30.1

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* Changes in Emacs 30.1

** X selection requests are now handled much faster and asynchronously.
This means it should be less necessary to disable the likes of
'select-active-regions' when Emacs is running over a slow network
connection.

** Emacs now updates invisible frames that are made visible by a compositor.
If an invisible or an iconified frame is shown to the user by the
compositing manager, Emacs will now redisplay such a frame even though
'frame-visible-p' returns nil or 'icon' for it.  This can happen, for
example, as part of preview for iconified frames.

+++
** 'write-region-inhibit-fsync' now defaults to t in interactive mode,
as it has in batch mode since Emacs 24.

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* Editing Changes in Emacs 30.1

** New helper variable 'transpose-sexps-function'.
Emacs now can set this variable to customize the behavior of the
'transpose-sexps' function.

** New function 'treesit-transpose-sexps'.
treesit.el now unconditionally sets 'transpose-sexps-function' for all
Tree-sitter modes.  This functionality utilizes the new
'transpose-sexps-function'.

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* Changes in Specialized Modes and Packages in Emacs 30.1
---
** Variable order and truncation can now be configured in 'gdb-many-windows'.
The new user option 'gdb-locals-table-row-config' allows users to
configure the order and max length of various properties in the local
variables buffer when using 'gdb-many-windows'.

By default, this user option is set to write the properties in the order:
name, type and value, where the name and type are truncated to 20
characters, and the value is truncated according to the value of
'gdb-locals-value-limit'.

If you want to get back the old behavior, set the user option to the value

    (setopt gdb-locals-table-row-config
            `((type . 0) (name . 0) (value . ,gdb-locals-value-limit)))

** VC

---
*** New user option 'vc-git-shortlog-switches'.
This is a string or a list of strings that specifies the Git log
switches for shortlogs, such as the one produced by 'C-x v L'.
'vc-git-log-switches' is no longer used for shortlogs.

** Buffer Selection

---
*** New user option 'bs-default-action-list'.
You can now configure how to display the "*buffer-selection*" buffer
using this new option.  (Or set 'display-buffer-alist' directly.)

** Eshell

+++
*** New splice operator for Eshell dollar expansions.
Dollar expansions in Eshell now let you splice the elements of the
expansion in-place using '$@expr'.  This makes it easier to fill lists
of arguments into a command, such as when defining aliases.  For more
information, see the "(eshell) Dollars Expansion" node in the Eshell
manual.

+++
*** 'eshell-read-aliases-list' is now an interactive command.
After manually editing 'eshell-aliases-file', you can use this command
to load the edited aliases.

** Prog Mode

+++
*** New command 'prog-fill-reindent-defun'.
This command either fills a single paragraph in a defun, such as a
docstring, or a comment, or (re)indents the surrounding defun if
point is not in a comment or a string.  It is by default bound to
'M-q' in 'prog-mode' and all its descendants.

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* New Modes and Packages in Emacs 30.1

---
** The highly accessible Modus themes collection has six items.
The 'modus-operandi' and 'modus-vivendi' are the main themes that have
been part of Emacs since version 28.  The former is light, the latter
dark.  In addition to these, we now have 'modus-operandi-tinted' and
'modus-vivendi-tinted' for easier legibility, as well as
'modus-operandi-deuteranopia' and 'modus-vivendi-deuteranopia' to
cover the needs of users with red-green color deficiency.  The Info
manual "(modus-themes) Top" describes the details and showcases all
their customization options.

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* Incompatible Lisp Changes in Emacs 30.1

** User option 'tramp-completion-reread-directory-timeout' has been removed.
This user option has been obsoleted in Emacs 27, use
'remote-file-name-inhibit-cache' instead.

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* Lisp Changes in Emacs 30.1

** New or changed byte-compilation warnings

---
*** Warn about empty bodies for more special forms and macros.
The compiler now warns about an empty body argument to 'when',
'unless', 'ignore-error' and 'with-suppressed-warnings' in addition to
the existing warnings for 'let' and 'let*'.  Example:

    (when (> x 2))

This warning can be suppressed using 'with-suppressed-warnings' with
the warning name 'empty-body'.

---
*** Warn about quoted error names in 'condition-case' and 'ignore-error'.
The compiler now warns about quoted condition (error) names
in 'condition-case' and 'ignore-error'.  Example:

    (condition-case nil
        (/ x y)
      ('arith-error "division by zero"))

Quoting them adds the error name 'quote' to those handled or ignored
respectively, which was probably not intended.

---
*** Warn about comparison with literal constants without defined identity.
The compiler now warns about comparisons by identity with a literal
string, cons, vector, record, function, large integer or float as this
may not match any value at all.  Example:

    (eq x "hello")

Only literals for symbols and small integers (fixnums), including
characters, are guaranteed to have a consistent (unique) identity.
This warning applies to 'eq', 'eql', 'memq', 'memql', 'assq', 'rassq',
'remq' and 'delq'.

To compare by (structural) value, use 'equal', 'member', 'assoc',
'rassoc', 'remove' or 'delete' instead.  Floats and bignums can also
be compared using 'eql', '=' and 'memql'.  Function literals cannot be
compared reliably at all.

This warning can be suppressed using 'with-suppressed-warnings' with
the warning name 'suspicious'.

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* Changes in Emacs 30.1 on Non-Free Operating Systems

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----------------------------------------------------------------------
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/>.

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