* test/lisp/cus-edit-tests.el (test-setopt): Change
'test-setopt' message text.

* test/lisp/progmodes/python-tests.el (python-ts-mode-dotted-decorator-face-2)
(python-ts-mode-builtin-call-face)
(python-ts-mode-level-fontification-wo-interpolation)
(python-ts-mode-disabled-string-interpolation): Call `font-lock-ensure`
after setting a var that may flush the font-locking.

* test/lisp/files-tests.el
(files-tests-file-name-non-special-insert-directory): Account for
'ls' error messages which designate 'ls' differently, e.g. as
'gls' or '/bin/ls' and which use different or no quoting of the
file name.

This change updates gnus-icalendar.el to use the new iCalendar
library instead of obsolete functions from icalendar.el.
* lisp/gnus/gnus-icalendar.el
(gnus-icalendar-event)
(gnus-icalendar-event:recurring-p)
(gnus-icalendar-event:recurring-interval)
(gnus-icalendar-event:recurring-days)
(gnus-icalendar-event--find-attendee)
(gnus-icalendar-event-from-ical)
(gnus-icalendar-event-from-buffer)
(gnus-icalendar-event--build-reply)
(gnus-icalendar-event-reply-from-buffer)
(gnus-icalendar-event:org-repeat): Reimplement using new iCalendar functions.
(gnus-icalendar-event--attendees-by-type): Rename from
`gnus-icalendar-event--get-attendee-names'.
(gnus-icalendar-event--build-reply): Rename from
`gnus-icalendar-event--build-reply-event-body'.
(gnus-icalendar--format-participant-list): Expect list of
`icalendar-attendee's.  Add docstring.
(Bug#80426)

* test/lisp/gnus/gnus-icalendar-tests.el: Update tests.

* lisp/net/tramp.el (tramp-skeleton-file-name-all-completions):
* lisp/net/tramp-adb.el (tramp-adb-handle-file-name-all-completions):
* lisp/net/tramp-crypt.el (tramp-crypt-handle-file-name-all-completions):
* lisp/net/tramp-fuse.el (tramp-fuse-handle-file-name-all-completions):
* lisp/net/tramp-gvfs.el (tramp-gvfs-handle-file-name-all-completions):
* lisp/net/tramp-sh.el (tramp-sh-handle-file-name-all-completions):
* lisp/net/tramp-smb.el (tramp-smb-handle-file-name-all-completions):
* lisp/net/tramp-sudoedit.el
(tramp-sudoedit-handle-file-name-all-completions): Simplify.
* tramp-tests.el (tramp-test32-shell-command): Adapt test.

* lisp/net/tramp-ftp.el (tramp-disable-ange-ftp): Use `seq-difference'.

* lisp/net/tramp-gvfs.el (tramp-gvfs-monitor-process-filter):
Use `thread-last'.

* lisp/net/tramp-sh.el (tramp-sh-handle-insert-directory):
Use `seq-difference'.
(tramp-sh-gio-monitor-process-filter): Use `thread-last'.

* lisp/net/tramp-smb.el (tramp-smb-get-file-entries): Do not add
virtual entry ""; it isn't needed anymore.

* lisp/net/tramp.el (tramp-make-tramp-hop-name): Use `thread-last'.
(tramp-completion-handle-file-directory-p): Use `tramp-prefix-format'.
(tramp-fnac-add-trailing-slash): New defvar.
(tramp-skeleton-file-name-all-completions): Handle also symlinked
directories.
(tramp-skeleton-directory-files): Use `tramp-fnac-add-trailing-slash'.
(tramp-handle-file-name-completion): Use `seq-difference'.
(tramp-handle-make-process): Handle "%w" format specifier.

* test/lisp/net/tramp-tests.el (tramp-test26-file-name-completion)
(tramp-test32-shell-command, tramp-test36-vc-registered): Adapt tests.

* test/lisp/files-tests.el
(files-tests-file-name-non-special-insert-directory): Fix for
MS-Windows and MS-DOS.
* test/lisp/dired-tests.el (dired-test-filename-with-newline-1)
(dired-test-filename-with-newline-2): Skip on MS-Windows/DOS.
Remove unused variable 'end'.
(dired-test-ls-error-message): Special testing for MS-Windows and
MS-DOS when they use 'ls-lisp'.
(Bug#80499)

The error messages are now displayed in a popped up buffer instead
of being output in the Dired buffer and signalling an error.  The
file name bounds in Dired entries are now determined solely by the
offsets calculated by 'ls' with the --dired option and
consequently Dired now reliably recognizes file names that contain
a newline (bug#80499).

* etc/NEWS: Announce new Dired handling of errors from 'ls'.

* lisp/dired.el (dired-internal-noselect): Check Dired buffer for
file entries and if there are none kill the buffer to prevent
displaying a Dired buffer with no file entries.
(dired--ls-error-buffer): New variable.
(dired--display-ls-error): New function.
(dired, dired-other-window, dired-other-frame, dired-other-tab):
Use it to pop up buffer with error message emitted by 'ls'.

* lisp/files.el (insert-directory-clean): Remove the code that
treats lines beginning at column 0 in a Dired buffer as error
lines and consequently also remove the code using these lines to
adjust the offsets specifying the bounds of the file name in the
Dired entries.  If the buffer contains a //DIRED-OPTIONS// line
output by --dired, delete this line even when it is at BOB.
(insert-directory): Remove the code that checks the return value
of 'ls' and signals an error based on that value.  Write any error
message emitted by 'ls' to a temporary file and insert its content
into a buffer, which will be popped when invoking a Dired command
results in the 'ls' error.  Adjust the comment above this function
to accommodate file names containing a newline in Dired entries.
(insert-directory-adj-pos): Remove this now unused function.

* test/lisp/dired-tests.el (dired-test-filename-with-newline-1)
(dired-test-filename-with-newline-2)
(dired-test-ls-error-message): New tests.

* test/lisp/files-tests.el
(files-tests-file-name-non-special-insert-directory): Adjust test
to use of 'ls' error buffer instead of signaling an error.