Like duplicate-line but duplicates the region instead if active.
Rectangular regions are duplicated on the right-hand side.
The region remains active afterwards, to facilitate further
duplication or other operations on the same text.

* lisp/rect.el (rectangle--duplicate-right):
* lisp/misc.el (duplicate-dwim): New.
* test/lisp/misc-tests.el (misc--duplicate-dwim): New test.
* etc/NEWS: Announce.

* lisp/align.el (align):
* lisp/bindings.el (undo-repeat-map):
* lisp/calc/calc-embed.el (calc-do-embedded):
* lisp/calc/calc-prog.el (calc-user-define-invocation):
* lisp/calc/calc-yank.el (calc--edit-mode):
* lisp/comint.el (comint-history-isearch)
* lisp/dired.el (dired-mode):
* lisp/emulation/viper.el (viper-mode):
* lisp/erc/erc-button.el (erc-button-face):
* lisp/erc/erc-track.el (erc-track-enable-keybindings):
* lisp/gnus/gnus-art.el (gnus-article-button-face):
* lisp/gnus/gnus-eform.el (gnus-edit-form):
* lisp/gnus/gnus-sum.el (gnus-summary-stop-at-end-of-message)
(gnus-summary-goto-unread):
* lisp/icomplete.el (icomplete-show-matches-on-no-input):
* lisp/image-mode.el (image-scroll-up):
* lisp/international/iso-transl.el (iso-transl-set-language):
* lisp/isearch.el (isearch-forward-regexp):
* lisp/misc.el (butterfly):
* lisp/outline.el (outline-minor-mode-cycle-filter)
(outline-minor-mode-cycle):
* lisp/progmodes/grep.el (rgrep):
* lisp/progmodes/gud.el (gud-gdb-repeat-map, gud-sdb-repeat-map)
(gud-dbx-repeat-map, gud-xdb-repeat-map, gud-perldb-repeat-map)
(gud-pdb-repeat-map, gud-guiler-repeat-map, gud-jdb-repeat-map):
* lisp/progmodes/idlw-shell.el (idlwave-shell-graphics-window-size)
(idlwave-shell-mode):
* lisp/progmodes/idlwave.el (idlwave-shell-debug-modifiers)
(idlwave-list-shell-load-path-shadows):
* lisp/progmodes/python.el (python-shell-get-process-or-error):
* lisp/repeat.el (repeat-check-key):
* lisp/replace.el (query-replace, query-replace-regexp)
(read-regexp):
* lisp/simple.el (read-extended-command-predicate):
* lisp/tab-bar.el (tab-bar-switch-repeat-map)
(tab-bar-move-repeat-map):
* lisp/term.el (ansi-term):
* lisp/textmodes/reftex-index.el (reftex-index-phrases-set-macro-key):
* lisp/vc/emerge.el (emerge-scroll-left, emerge-scroll-right):
* lisp/windmove.el:
* lisp/winner.el (winner-mode): Quote literal keys to get
'help-key-binding' face.
* lisp/comint.el (comint-insert-previous-argument): Use regular
quotes.

The test assumes that the current semantics are intended and desired,
which may or may not be true, but it's better than not having any at
all.

* lisp/misc.el (duplicate-line): Don't crash if called with no argument.
* test/lisp/misc-tests.el (misc--duplicate-line): New test.

* lisp/misc.el (copy-from-above-command): Fix doc string typo.

* lisp/misc.el (copy-from-above-command): Mention it.
(duplicate-line): New command (bug#46621).

In interactive calls, behave case-sensitively if the given char
is an upper-case character.  Same for zap-up-to-char (Bug#54804).

This is analog to what the user-level incremental search feature does.

* lisp/misc.el (zap-up-to-char): Add an optional arg INTERACTIVE.
Perform a case-sensitive search when INTERACTIVE is non-nil and
CHAR is an upper-case character.
* lisp/simple.el (zap-to-char): Same.

* etc/NEWS (Editing Changes in Emacs 29.1): Announce this change.
* test/lisp/misc-tests.el (misc-test-zap-up-to-char): Add test cases.
* test/lisp/simple-tests.el (with-zap-to-char-test): Add helper macro.
(simple-tests-zap-to-char): Add a test.

* lisp/emacs-lisp/seq.el (seq-contains): Move the ‘declare’ form
after the docstring.
* lisp/misc.el (copy-from-above-command): Fix whitespace regexp.

Run "TZ=UTC0 admin/update-copyright".