Fix image-mode-fit-frame resizing

* lisp/image-mode.el (image-mode-fit-frame): Use pixel sizes
instead of lines/columns to get more accurate resizing (bug#37630).

* lisp/term/pgtk-win.el: Update header comment.

Fix hl-line tests

* lisp/hl-line.el (hl-line-mode): Restore old setter.
* test/lisp/hl-line-tests.el (hl-line-tests-verify): Don't rely
`cl-some' always returning t on success.
(hl-line-tests-sticky-across-frames): Use correct global variable.

* lisp/calendar/todo-mode.el: Restore old code.

Restore old hl-line code

* lisp/hl-line.el: Restore old code to remove obsoletions.
(hl-line-overlay-priority): Make defcustom.

Allow retrieving some more kinds of clipboard data on Haiku

* src/haiku_select.cc (BClipboard_find_data): Handle NULL
characters inside data correctly.
(be_lock_clipboard_message, be_unlock_clipboard): New functions.
* src/haikuselect.c (Fhaiku_selection_data): Return entire
clipboard contents as a message when clipboard is NULL.
(haiku_lisp_to_message): Allow quitting when iterating through
potentially large or circular lists.
* src/haikuselect.h (enum haiku_clipboard): New enum.

; Merge from origin/emacs-28

The following commit was skipped:

c69a617742 Add notes about command modes and nativecomp interaction

Fix crash in haiku_message_to_lisp

* src/haikuselect.c (haiku_message_to_lisp): Block input around
`free'.

Handle quitting correctly during interprogram drag-and-drop

* lisp/mouse.el (mouse-drag-and-drop-region): Handle quit
correctly by exiting the cross program drag and drop.

* src/xterm.c (x_dnd_begin_drag_and_drop): Fix test against DND frame.

Don't allocate duplicate cursors for each frame on Haiku

* src/haikufns.c (haiku_create_frame)
(haiku_free_frame_resources): Stop creating cursors.
* src/haikuterm.c (haiku_delete_terminal, haiku_term_init):
Create and free cursors here instead.
* src/haikuterm.h (struct haiku_display_info): New fields for
cursors.

Improve DND documentation

* doc/lispref/frames.texi (Drag and Drop):
* src/xfns.c (Fx_begin_drag): Document meaning of
`XdndActionPrivate'.

; * src/xterm.c (x_free_frame_resources): Fix typo in last change.

Reported taken action correctly when dragging to another frame on X

* src/xterm.c (x_dnd_cleanup_drag_and_drop, x_dnd_update_state)
(x_free_frame_resources, handle_one_xevent): Set
`x_dnd_end_window'.
(x_dnd_begin_drag_and_drop): Return `XdndActionPrivate' if the
drop landed on one of our own frames.

Refactor gnus/nnselect artlist saving and getting

* lisp/gnus/nnselect.el (nnselect-generate-run): New function that
replaces nnselect-run.
(nnselect-store-artlist): New function.
(nnselect-get-artlist): Update function.
(nnselect-request-group, nnselect-request-thread)
(nnselect-request-create-group, nnselect-request-group-scan): Use the
new functions.
* doc/misc/gnus.texi (Selection Groups): Document artlist storage and
retrieval.

NEWS copy edits

Mention highlight-confusing-reorderings in doc string

* src/xdisp.c (Fbidi_find_overridden_directionality): Mention
highlight-confusing-reorderings.

Mention the other-window-scroll-default user option

* src/window.c (Fscroll_other_window): Link to
other-window-scroll-default in the doc string.

Document outline-default-state

* doc/emacs/text.texi (Outline Visibility): Mention
outline-default-state.

Do some NEWS tagging

Document sqlite-mode-open-file and do some NEWS tagging

* doc/lispref/text.texi (Database): Mention sqlite-mode-open-file.

Enable Better Alignment of EUDC Inline Expansion With RFC5322

The format of EUDC inline expansion results is formatted according to
the variable eudc-inline-expansion-format, which previously defaulted
to '("%s %s <%s>" firstname name email).

Since email address specifications need to comply with RFC 5322 in
order to be useful in messages, there was little headroom for users to
change this format anyway. Plus, if an EUDC back-end returned an empty
first and last name, the result was the email address in angle
brackets. Whilst this was standard with RFC 822, it is marked as
obsolete syntax by its successor RFC 5322. Also, the first and last
name part was never enclosed in double quotes, potentially producing
invalid address specifications, which may be rejected by a receiving
MTA.

This commit updates the variable eudc-inline-expansion-format, so that
it can, in addition to the current ("format" attributes) list, now
alternatively be set to nil, or a formatting function. In both cases
the resulting email address is formatted using the new function
eudc-rfc5322-make-address, whose results fully comply with RFC 5322.

If the value is nil (the new default value), eudc-rfc5322-make-address
will be called to produce any of the default formats

                               ADDRESS
                           FIRST <ADDRESS>
                            LAST <ADDRESS>
                         FIRST LAST <ADDRESS>

depending on whether a first and/or last name are returned by the
query, or not.

If the value is a formatting function, that will be called to allow
the user to supply content for the phrase and comment parts of the
address (cf. RFC 5322). Thus one can produce any of the formats:

                               ADDRESS
                           PHRASE <ADDRESS>
                          ADDRESS (COMMENT)
                      PHRASE <ADDRESS> (COMMENT)

This can for example be used to get "last, first <address>" instead of
the default "first last <address>".

In any case when using nil, or the formatting function, the phrase
part of the result will be enclosed in double quotes if needed, and
the comment part will be omitted if it contains characters not allowed
by RFC 5322.

When eudc-inline-expansion-format remains set to a list as previously,
the old behaviour is fully retained.

Fix two no-X compilation warnings

* lisp/mouse.el (x-hide-tip, x-show-tip): Declare to avoid no-X
build compilation warnings (bug#54524).

* lisp/term/pgtk-win.el (window-system-initialization): Avoid no-X
compilation warning.

Fix a keyboard.c no-X compilation warning

* src/keyboard.c (make_lispy_position): Fix compilation warning in
a --without-x build.

Make mail-header-parse-addresses-lax more lax

* lisp/mail/mail-parse.el (mail-header-parse-addresses-lax): Be
more resilient (bug#54523).

Fix Completion Options typo

* doc/emacs/mini.texi (Completion Options): Fix typo.

Add a shell-filter-ring-bell function

* lisp/shell.el (shell-mode): Mention it.
(shell-filter-ring-bell): New function (bug#21652).

Fix documentation of the new completion-related features

* etc/NEWS:
* lisp/minibuffer.el (completion-auto-help):
* doc/lispref/text.texi (Special Properties):
* doc/emacs/mini.texi (Completion Options): Fix wording of
recently added documentation and customization options.

Revert "Set cursor-face-highlight-nonselected-window in completions."

This reverts commit 1641b5c04c383b5f53298d70776e3c18577b6f30.

This fixes incorrect highlight in Completions.

Add user option for controlling dired-do-shell-command prompt

* doc/emacs/dired.texi (Shell Commands in Dired): Document option
* lisp/dired-aux.el (dired-confirm-shell-command): Add option
(dired-do-shell-command): Check option before prompting
(bug#29465).

Make eshell link faces more distinctive on 8-color displays

* lisp/eshell/em-ls.el (eshell-ls-directory):
(eshell-ls-symlink): Make the faces be distinctive on 8-colour
displays (bug#43615).

Restore hl-line--buffer tracking

* lisp/hl-line.el (hl-line-overlay, hl-line-overlay-buffer):
Correct replacement variable.
(hl-line--overlay): Clearer doc.
(hl-line--buffer): Nee hl-line-overlay-buffer
(hl-line-sticky-flag): Custom initialization is unfathomable.
(hl-line-mode, hl-line-unhighlight): Orthogonalize sticky.
(hl-line-highlight): Remove highlight from previous buffer.
* test/lisp/hl-line-tests.el (hl-line-sticky, hl-line-tests-verify):
(hl-line-tests-sticky-across-frames, hl-line-tests-sticky):
Test (bug#54481).

Revert "Fix dependency problem in hl-line-sticky-flag"

This reverts commit 46daf70c4a7ce208ab0b3a7893c042fed5f022c2.

This is fixed differently in a subsequent patch.

Fix dependency problem in hl-line-sticky-flag

* lisp/hl-line.el (hl-line-sticky-flag): Open-code
hl-line-unhighlight to avoid recursive dependencies (bug#54481).

Fix color-lighten-hsl logic

* lisp/color.el (color-lighten-hsl): Lighten by percentage,
instead of just adding the specified number to the luminance
element (bug#54514).

Revert todo-mode tests failing after todo-mode reversion

Add new function image-supported-file-p

* lisp/image.el (image-type-from-file-name): Make obsolete.
(image-supported-file-p): New function that has a more sensible
value.
(image-type): Adjust caller.

* lisp/thumbs.el (thumbs-file-size, thumbs-show-image-num): Adjust
callers.

* lisp/mail/rmailmm.el (rmail-mime-set-bulk-data): Adjust caller
and logic.

Revert "Allow using image-convert to view .bmp images"

This reverts commit ede8ad507d06a336ce8202927f214aecbaf15d6b.

This leads to failures for usages of the function where
Emacs doesn't have support for the formats.

Simplify fullscreen management on Haiku

* src/haiku_support.cc (class EmacsWindow, Zoom, UnZoom): Track
zoom state manually instead of guessing what the system
currently thinks it is.
(MakeFullscreen): Always unzoom first.
* src/haiku_support.h (struct haiku_zoom_event): Remove all
fields and add a single field `zoomed'.
* src/haikufns.c (haiku_create_frame, haiku_create_tip_frame):
Remove use of pending_zoom fields.
* src/haikuterm.c (haiku_read_socket): Simplify handling of zoom
events.
(haiku_fullscreen): Simplify handling of different zoom states.
* src/haikuterm.h (struct haiku_output): Remove all pending_zoom
fields since they are no longer required.

Fix grep-like functions when running on a remote host

* doc/lispref/processes.texi (Shell Arguments):
* etc/NEWS: Describe change in 'shell-quote-argument'.  Fix typos.

* lisp/subr.el (shell-quote-argument): New optional argument POSIX.

* lisp/progmodes/grep.el (grep-compute-defaults)
(grep-default-command, grep-expand-keywords, lgrep)
(rgrep-default-command): Use POSIX argument in
`shell-quote-argument'.  (Bug#54487)

* src/comp.c: Few improvements following 71b8f1fc635.

* src/comp.c (ABI_VERSION): Update.
(Fcomp__register_lambda, Fcomp__register_subr): Remove unnecessary
check.
* src/comp.c (Fcomp__register_lambda, Fcomp__register_subr):
Remove unnecessary change.

* src/xterm.c (x_dnd_get_window_proto): Don't return huge protocols.

Merge branch 'feature/completions-customs'

Fix starting Emacs with -mm or -fs on Haiku

* src/haikuterm.c (haiku_set_window_size): Disallow setting the
window size if the frame is fullscreen, like most X window
managers.

Fix leak of saved menu event and output data

* src/xterm.c (x_destroy_window, x_free_frame_resources): Free
output data and saved menu event even if display is closed.

Fix unloading the hl-line library

* lisp/hl-line.el (hl-line-unload-function): Restore function.

Fix incompatible changes in hl-line

* lisp/hl-line.el (hl-line-face): Rename back to hl-line.
(hl-line-face): Restore defcustom.

Small fixes for new completions features

* lisp/minibuffer.el (completions-header-format):
Rename from completion-header-format.
(completions-highlight, completions-highlight-face):
Move up before first use.

Add new user option `diff-entire-buffers'

* lisp/vc/diff.el (diff-entire-buffers): New user option (bug#54060).
(diff-file-local-copy): Use it.
(diff-buffers): Mention it in the doc string.

Don't break autoload generation of `left-margin' isn't zero

* lisp/emacs-lisp/autoload.el (make-directory-autoloads): Fix
autoload generation breakage is left-margin isn't zero (bug#54491).

Make `n' in image-mode work more reliably with external formats

* lisp/image-mode.el (image-mode): Init the external machinery so
that commands like `n' work for those files.
* lisp/image/image-converter.el (image-converter-initialize):
Factored out into own function.
(image-convert-p): Use it.
(image-convert): Ditto.

Allow specifying the intermediate format

* lisp/image/image-converter.el (image-convert-to-format): New
user format (bug#54494).
(image-convert, image-converter--convert-magick)
(image-converter--convert): Use it.

Allow using image-convert to view .bmp images

* lisp/image.el (image-type-from-file-name): Allow Emacs to fall
back on image-convert to display .bmp images (bug#54492).

Regenerated ldefs-boot.el

Rewrite hl-line-mode

The fashion of dual global and minor modes, each managing a replica of
state, has long been outmoded by globalized minor modes (nee
easy-mmode-define-global-mode) around the turn of the century.

* lisp/calendar/todo-mode.el (todo-toggle-item-highlighting,
todo-hl-line-range, todo-modes-set-2): Adapt to new
hl-line-highlight-hook.
* lisp/hl-line.el (hl-line-overlay): Rename hl-line--overlay.
(global-hl-line-overlay, global-hl-line-overlays,
global-hl-line-sticky-flag, hl-line-overlay-buffer,
hl-line-range-function): Obsolesce.
(hl-line--overlay): Erstwhile hl-line-overlay.
(hl-line, hl-line-face): Consolidate.
(hl-line-sticky-flag): Say less (Gen Z Hospital).
(hl-line-overlay-priority): Make this a custom.
(hl-line-highlight-hook): Prefer hook over specialized
hl-line-range-function.
(hl-line-mode): Say less (Gen Z Hospital).
(hl-line-make-overlay): Remove
(hl-line-highlight, hl-line-unhighlight): Rewrite.
(hl-line-maybe-unhighlight): Remove.
(hl-line-turn-on): Necessary for globalized minor mode.
(global-hl-line-mode, global-hl-line-highlight,
global-hl-line-highlight-all, global-hl-line-unhighlight,
global-hl-line-maybe-unhighlight, global-hl-line-unhighlight-all):
Prefer globalized minor mode.
(hl-line-move, hl-line-unload-function): Remove.
* test/lisp/calendar/todo-mode-tests.el (todo-test-item-highlighting,
todo-test-done-items-separator06-bol,
todo-test-done-items-separator06-eol,
todo-test-done-items-separator07): Adapt to consolidated face.

Add a new face shr-code

* lisp/net/shr.el (shr-code): New face (bug#54480).
(shr-tag-code): Use it.

Add notes about command modes and nativecomp interaction

* doc/lispref/commands.texi (Command Modes): Note interaction with
native-compile (bug#54437).

* src/data.c: Add comment about not being supported.

Do not merge to master.

; * src/comp.c: Update a comment.

Minor fixes to Haiku DND support

* src/haiku_support.cc (MessageReceived): If source is remote,
don't test window ID.
(MouseMoved): Don't send mouse motion if dragging.
(be_drag_message): Return true if quit-flag.
* src/haiku_support.h: Update prototypes.
* src/haikuselect.c (haiku_should_quit_drag): New function.
(Fhaiku_drag_message): If rc is true, quit.

Set cursor-face-highlight-nonselected-window in completions.

* lisp/simple.el (completion-setup-function) : Sets
cursor-face-highlight-nonselected-window to t in Completions.

Merge from origin/emacs-28

f15922a57c Update to Org 9.5.2-25-gaf6f12
9fcdd5b63f Improve doc strings of read-char-from-minibuffer-insert-* ...

Improve handling of input methods during drag-and-drop

* src/xterm.c (x_dnd_cleanup_drag_and_drop)
(x_dnd_begin_drag_and_drop): Stop removing IC and filter events
before dispatching them.
(x_filter_event): Actually filter events during DND.
(XTread_socket): Verify GenericEvents are actually input
extension events before ignoring them.

Make quitting work while DND is waitng for finish

* src/xterm.c (x_dnd_cleanup_drag_and_drop):
(x_dnd_begin_drag_and_drop, handle_one_xevent)
(x_free_frame_resources): Clear waiting for finish flag.
(x_filter_event): Don't filter if waiting for DND finish as
well.

Update to Org 9.5.2-25-gaf6f12

Support indentation of Ruby pattern matching expressions

* lisp/progmodes/ruby-mode.el (ruby-smie-grammar, ruby-smie-rules)
(ruby-block-mid-keywords): Treat 'in' token similarly to 'when'.

* test/lisp/progmodes/ruby-mode-resources/ruby.rb:
Add indentation example.

Fix imap fetching multiple mailboxes (bug#54158)

* lisp/gnus/mail-source.el (mail-source-fetch-imap): Variables
mailbox-source-string and remove should be reset for each mailbox.

* etc/NEWS: Mention new hook 'minibuffer-lazy-highlight-setup'.

Add lazy highlight to 'isearch-edit-string'

* lisp/isearch.el (isearch-edit-string): Activate lazy highlight and
lazy count, provided 'isearch-lazy-highlight' respectively
'isearch-lazy-count' are non-nil.

Allow lazy highlight and match count while reading from minibuffer

* lisp/isearch.el (minibuffer-lazy-highlight-setup): New function, can
be added to 'minibuffer-setup-hook' to enable lazy highlight and count
while reading from minibuffer.
(minibuffer-lazy-count-format, minibuffer-lazy-highlight-transform,
minibuffer-lazy-highlight--overlay, minibuffer-lazy-highlight--count,
minibuffer-lazy-highlight--after-change,
minibuffer-lazy-highlight--exit): Auxiliary variables and functions
implementing the lazy highlight functionality while reading from
minibuffer.

New hook, lazy-count-update-hook

* lisp/isearch.el (lazy-count-update-hook): New hook allowing to
display the lazy count in special ways.
(isearch-lazy-highlight-new-loop,
isearch-lazy-highlight-buffer-update): Run `lazy-count-update-hook' at
appropriate times.
* lisp/comint.el (comint-history-isearch-setup,
comint-history-isearch-end): Make sure no lazy count is displayed.
* lisp/simple.el (minibuffer-history-isearch-setup): Make sure no lazy
count is displayed.

* lisp/tab-bar.el (tab-bar-new-tab-to): Don't funcall const values.

Filter out the values 'clone' and 'window' of 'tab-bar-new-tab-choice'
from function call.

Extend connection-local variables example in Elisp manual

* doc/lispref/variables.texi (Connection Local Variables):
Explain, how to append variable settings to an existing profile.

Remove duplicate INLINE_HEADER_BEGIN

* src/thread.h: Remove duplicate INLINE_HEADER_BEGIN.
Problem reportd by Mattias Engdegård.

Improve doc strings of read-char-from-minibuffer-insert-* commands

* lisp/subr.el (read-char-from-minibuffer-insert-char)
(read-char-from-minibuffer-insert-other): Clarify the doc strings.
(Bug#54479)

Fix confusion of wanted action with actual action on X

* src/xterm.c (x_dnd_begin_drag_and_drop)
(x_dnd_update_state, handle_one_xevent): Differentiate between
wanted action and chosen action correctly.

Fix wrong password stored in Tramp

* lisp/net/tramp.el (tramp-process-actions):
Unset `tramp-password-save-function'.

Make DND between frames work properly

* src/xterm.c (handle_one_xevent): Don't wait for a finish event
when dropping on top of another Emacs frame.

Improve compliance with version 5 of the XDND specification

* src/xterm.c (x_dnd_cleanup_drag_and_drop): New function.
(x_dnd_begin_drag_and_drop): Handle selection request events
immediately.
(handle_one_xevent): Wait for XdndFinished events and return the
action chosen there.

Fix some crashes in shut_down_emacs on Haiku

* src/emacs.c (shut_down_emacs): Stop quitting be app, since
it's not always there.

Implement `haiku_delete_terminal'

* src/haikuterm.c (haiku_delete_terminal): Actually delete the
terminal instead of aborting.

Check list tail properly in x-begin-drag

* src/xfns.c (Fx_begin_drag): Check that TARGETS is actually a
proper list.
* src/xterm.c (x_dnd_update_state): Remove debugging code.

Fix crash on some compositing managers

* src/xterm.c (x_dnd_get_target_window): Catch errors around
CompositeReleaseOverlayWindow.

Improve behaviour of drag-n-drop during window manager operations

* src/xterm.c (x_dnd_begin_drag_and_drop): Select for some
events on the root window.
(x_dnd_update_state): New function.
(handle_one_xevent): Call that function when we get some events
from the root window substructure or the window manager.
(x_term_init): New atom `_NET_CLIENT_LIST_STACKING'.
* src/xterm.h (struct x_display_info): New atom
`_NET_CLIENT_LIST_STACKING'.

Merge branch 'master' of git.savannah.gnu.org:/srv/git/emacs

Port to gcc -D EMACS_EXTERN_INLINE

* src/comp.h, src/thread.h: Add INLINE_HEADER_BEGIN and
INLINE_HEADER_END, since it uses INLINE.
* src/emacs.c: Include these two files.

valid_sp inline fix

* src/bytecode.c (valid_sp): static, not INLINE, as INLINE
should be used only in headers and between INLINE_HEADER_BEGIN
and INLINE_HEADER_END.  No need for ‘inline’ here.

Simplify alloc.c static function decls

* src/alloc.c: Omit unnecessary static function declarations.
Don’t use ‘inline static’ as the C standard says that keyword
order is obsolescent.  Anyway, no need for ‘inline’ as compilers
inline without it well enough.

Make native helper functions static

These don’t need to be extern, even with -flto, since
their addresses are taken.
* src/comp.c (helper_unwind_protect, helper_unbind_n)
(helper_save_restriction, helper_GET_SYMBOL_WITH_POSITION)
(helper_PSEUDOVECTOR_TYPEP_XUNTAG): Now static.

Remove unused fns/data and make fns static

* src/comp.c (saved_sigset, helper_temp_output_buffer_setup):
Remove; unused.
* src/comp.c (logfile, helper_link_table):
* src/fns.c (hashfn_equal, hashfn_eql):
* src/frame.c (frame_windows_min_size):
* src/gnutls.c (emacs_gnutls_global_init):
* src/minibuf.c (Vcommand_loop_level_list):
* src/syntax.c (syntax_code_spec):
* src/timefns.c (time_overflow):
* src/xterm.c (x_xrender_color_from_gc_foreground)
(x_display_set_last_user_time):
Now static, since it’s not used elsewhere.
* src/xterm.c (x_xrender_color_from_gc_foreground)
(x_xrender_color_from_gc_background): Move earlier to avoid
forward use.
(x_xrender_color_from_gc_foreground): Do not define unless
!defined USE_CAIRO && (RENDER_MAJOR > 0 || RENDER_MINOR >= 2),
since it’s not used otherwise.

Use filenvercmp instead of doing it by hand

* src/fns.c (Fstring_version_lessp): Use filenvercmp,
not string_version_cmp.
(string_version_cmp): Remove; no longer used.

Omit unnecessary code when !HAVE_NATIVE_COMP

* src/decompress.c (MD5_BLOCKSIZE, acc_buf, acc_size)
(accumulate_and_process_md5, final_process_md5, md5_gz_stream):
* src/dynlib.c (dynlib_open_for_eln, dynlib_close) [!WINDOWSNT]:
* src/fileio.c (internal_delete_file_1, internal_delete_file):
Define only if HAVE_NATIVE_COMP && WINDOWSNT,
as they’re not used otherwise.

Remove internal_condition_case_[345]

* src/comp.c (directory_files_matching) [WINDOWSNT]: New function.
(eln_load_path_final_clean_up) [WINDOWSNT]: Use it.
This removes the need for internal_condition_case_5.
* src/eval.c (internal_condition_case_3)
(internal_condition_case_4, internal_condition_case_5): Remove.
The first two were never used; the last only in now-removed code.

Remove sanitize_window_sizes

* src/window.c (sanitize_window_sizes): Remove; no-longer-used.
A previous refactoring moved this to Lisp without removing the C code.

Merge branch 'master' of git.savannah.gnu.org:/srv/git/emacs

Make `command-modes' work for (native-compiled) subrs, too

* lisp/emacs-lisp/comp.el (comp-func): Add a command-modes slot.
(comp-spill-lap-function, comp-intern-func-in-ctxt): Fill it.
(comp-emit-for-top-level, comp-emit-lambda-for-top-level): Use it.

* src/alloc.c (mark_object): Mark the command_modes slot.

* src/comp.c (make_subr): Add a command_modes parameter.
(Fcomp__register_lambda): Use it.
(Fcomp__register_subr): Ditto.

* src/data.c (Fcommand_modes): Output the command_modes data for subrs
(bug#54437).

* src/lisp.h (GCALIGNED_STRUCT): Add a command_modes slot.

* src/pdumper.c (dump_subr): Update hash.
(dump_subr): Dump the command_modes slot.

Improve protection against faulty clients during DND

* src/xterm.c (x_dnd_send_enter, x_dnd_send_position)
(xdnd_send_leave, x_dnd_send_drop): Catch errors around call to
XSendEvent.  The target window could be gone.

; * test/lisp/erc/erc-tests.el (erc--switch-to-buffer): Fix test failure.

Remove redundant checks in erc--switch-to-buffer

* lisp/erc/erc.el (erc--switch-to-buffer): Commit
f925fc93bac41d7622d1af927e33b0e738ff55b0 "Add `predicate' arg to
`read-buffer' and use it for erc-iswitchb" meant to remove this, but
it was left behind. (Bug#53617)

Copyright-paperwork-exempt: yes

Add unit test for erc--switch-to-buffer

* test/lisp/erc/erc-tests.el (erc--switch-to-buffer): Add new test.
(Bug#53617)

Merge from origin/emacs-28

e059d7c Fix region highlight in non-selected windows