* src/buffer.c (overlays_in): Fix commentary to match the code.
(Foverlays_in, Foverlays_at): Doc fixes.  (Bug#80242)

* test/src/buffer-tests.el (test-overlays-at-2): Add one test.

* doc/lispref/display.texi (Finding Overlays): Update and improve
the documentation of 'overlays-in' and 'overlays-at'.

* etc/NEWS: Announce the changes.

This restores the original behavior of 'overlays_in'.  Changes in
this behavior had been made for cases of narrowing, but this
resulted in a regression with uses of 'remove-overlays'.

* src/buffer.c (overlays_in): Change all occurrences of ZV to Z.

* test/src/buffer-tests.el (test-overlays-in-2)
(test-remove-overlays): Adjust expected results to accommodate
changes in 'overlays_in'.

* etc/NEWS: Announce the change.
* src/dispextern.h (struct glyph_row): Add
'extra_line_spacing_above' member.
(struct it): Add 'extra_line_spacing_above' member.
* src/frame.h (struct frame): Add 'extra_line_spacing_above'
member.  Update comment for 'extra_line_spacing.'
* src/buffer.c (syms_of_buffer): Update the docstring of
'line-spacing' to describe the cons cell usage.
* src/buffer.h (struct buffer): Update comment for
'extra_line_spacing'.
* src/frame.c (gui_set_line_spacing): Handle cons cell value for
'line-spacing'.  Calculate and set 'extra_line_spacing_above'
for both integer and float pairs.
* src/xdisp.c (init_iterator): Initialize 'extra_line_spacing_above'
from buffer or frame 'line-spacing', handling cons cells for both
integer and float values.
(gui_produce_glyphs): Use 'extra_line_spacing_above' to distribute
spacing between ascent and descent.  Update 'max_extra_line_spacing'
calculation.
(resize_mini_window): Take line spacing into account when resizing the
mini window.  Pass height of a single line to 'grow_mini_window' and
'shrink_mini_window'.
* src/window.c (grow_mini_window, shrink_mini_window): Add unit
argument which defines height of a single line.
* src/window.h (grow_mini_window, shrink_mini_window): Adjust function
prototypes accordingly with unit argument.
* lisp/subr.el (total-line-spacing): New function to calculate total
spacing from a number or cons cell.
(posn-col-row): Use total-line-spacing.
* lisp/simple.el (default-line-height): Use 'total-line-spacing'.
* lisp/textmodes/picture.el (picture-mouse-set-point): Use
'total-line-spacing'.
* lisp/window.el (window-default-line-height): Use
'total-line-spacing'.
(window--resize-mini-window): Take 'line-spacing' into account.
* test/lisp/subr-tests.el (total-line-spacing): New test.
* test/src/buffer-tests.el (test-line-spacing): New test.
* doc/emacs/display.texi (Display Custom): Document that
'line-spacing' can be a cons cell.
(Line Height): Document the new cons cell format for 'line-spacing'
to allow vertical centering.

Co-authored-by: Przemysław Alexander Kamiński <alexander@kaminski.se>
Co-authored-by: Daniel Mendler <mail@daniel-mendler.de>

* test/src/buffer-tests.el (test-restore-buffer-modified-p)
(test-buffer-chars-modified-ticks): Don't leave unsaved and
modified file buffers after the tests.

* test/lisp/dired-aux-tests.el (dired-test-bug30624):
* test/lisp/emacs-lisp/track-changes-tests.el
(track-changes-tests--random):
* test/src/buffer-tests.el (test-buffer-chars-modified-ticks):
* test/src/fileio-tests.el (fileio-tests--symlink-failure)
(fileio-tests--insert-file-interrupt)
(fileio-tests--circular-after-insert-file-functions): Prefer
ert-with-temp-directory to using make-temp-file directly.

* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-reify-function):
* test/lisp/emacs-lisp/cl-extra-tests.el (cl-getf):
* test/lisp/emacs-lisp/cl-macs-tests.el
(cl-macs-loop-for-as-arith-order-side-effects)
(cl-macs-loop-for-as-equals-then, cl-macs-loop-do, cl-macs-loop-finally)
(cl-macs-loop-in-ref, cl-macs-loop-being-elements-of-ref)
(cl-macs-test--symbol-macrolet, cl-the):
* test/lisp/emacs-lisp/cl-seq-tests.el (cl-lib-test-remove)
(cl-lib-test-remove-if-not):
* test/lisp/emacs-lisp/edebug-resources/edebug-test-code.el
(edebug-test-code-range):
* test/lisp/emacs-lisp/edebug-tests.el (edebug-tests-deduplicate):
* test/lisp/emacs-lisp/generator-tests.el (cps-while-incf):
(cps-test-iter-cleanup-once-only):
* test/lisp/emacs-lisp/hierarchy-tests.el
(hierarchy-labelfn-button-if-does-not-button-unless-condition)
(hierarchy-labelfn-button-if-does-button-when-condition):
* test/lisp/emacs-lisp/let-alist-tests.el (let-alist-evaluate-once):
* test/lisp/emacs-lisp/lisp-mode-tests.el
(indent-sexp, lisp-indent-region):
* test/lisp/emacs-lisp/map-tests.el (test-map-elt-gv)
(test-setf-map-with-function):
* test/lisp/emacs-lisp/multisession-tests.el (multi-test-sqlite-simple)
(multi-test-sqlite-busy, multi-test-files-simple)
(multi-test-files-busy):
* test/lisp/emacs-lisp/oclosure-tests.el
(oclosure-test, oclosure-test-mutate):
* test/lisp/emacs-lisp/track-changes-tests.el
(track-changes-tests--random):
* test/lisp/files-tests.el (files-tests--with-buffer-offer-save):
* test/lisp/net/shr-tests.el (shr-test/zoom-image):
* test/lisp/replace-tests.el (replace-tests-with-undo):
* test/src/buffer-tests.el (test-overlay-randomly):
* test/src/data-tests.el (test-bool-vector-bv-from-hex-string):
* test/src/fns-tests.el (fns-tests-sort):
* test/src/json-tests.el (json-insert/signal, json-insert/throw):
* test/src/minibuf-tests.el (minibuf-tests--strings-to-symbol-alist)
(minibuf-tests--strings-to-string-alist)
(minibuf-tests--strings-to-string-hashtable)
(minibuf-tests--strings-to-symbol-hashtable):
* test/src/process-tests.el (make-process/file-handler/found): Prefer
incf to cl-incf.

* lisp/auth-source-pass.el (auth-source-pass--find-match-many):
* lisp/calendar/time-date.el (decoded-time-add)
(decoded-time--alter-month, decoded-time--alter-day):
* lisp/dired.el (dired--move-to-next-line):
* lisp/dom.el (dom-pp):
* lisp/emacs-lisp/cl-macs.el (cl--transform-lambda):
* lisp/emacs-lisp/cl-print.el (cl-print-to-string-with-limit):
* lisp/emacs-lisp/cl-seq.el (cl-fill, cl-replace, cl-substitute):
* lisp/emacs-lisp/comp-cstr.el (comp--range-union)
(comp--range-intersection):
* lisp/emacs-lisp/comp.el (comp-vec-prepend, comp--emit-narg-prologue):
* lisp/emacs-lisp/edebug.el (edebug--strip-instrumentation):
* lisp/emacs-lisp/eldoc.el (eldoc--invoke-strategy):
* lisp/emacs-lisp/pp.el (pp--format-definition):
* lisp/emacs-lisp/smie.el (smie-config--guess-1):
* lisp/eshell/esh-io.el (eshell-close-handle, eshell-set-output-handle):
* lisp/gnus/gnus-async.el (gnus-async-prefetch-article):
* lisp/gnus/gnus-group.el (gnus-group-mark-group)
(gnus-group-yank-group):
* lisp/gnus/gnus-salt.el (gnus-tree-forward-line):
* lisp/gnus/gnus-score.el (gnus-decay-scores):
* lisp/gnus/gnus-srvr.el (gnus-browse-toggle-subscription-at-point):
* lisp/gnus/gnus-sum.el (gnus-build-sparse-threads, gnus-parent-headers)
(gnus-update-marks, gnus-summary-work-articles)
(gnus-summary-refer-parent-article, gnus-summary-next-thread)
(gnus-read-header, gnus-summary-insert-new-articles):
* lisp/gnus/gnus-topic.el (gnus-topic-forward-topic):
* lisp/gnus/gnus.el (gnus-short-group-name):
* lisp/gnus/message.el (message-remove-first-header)
(message-shorten-references, message-insert-screenshot):
* lisp/gnus/mm-url.el (mm-url-insert):
* lisp/gnus/nnselect.el (nnselect-push-info):
* lisp/ibuffer.el (ibuffer-backward-line, ibuffer-forward-line)
(ibuffer-map-lines):
* lisp/icomplete.el (icomplete--render-vertical):
* lisp/image/image-dired-external.el (image-dired-create-thumb-1):
* lisp/image/image-dired.el (image-dired-delete-char):
* lisp/mail/ietf-drums-date.el (ietf-drums-date--tokenize-string):
* lisp/mh-e/mh-utils.el (mh-sub-folders-parse):
* lisp/minibuffer.el (minibuffer-completion-help):
* lisp/mpc.el (mpc-cmd-move, mpc-songpointer-refresh-hairy):
* lisp/net/eww.el (eww-process-text-input):
* lisp/net/pop3.el (pop3-wait-for-messages, pop3-uidl-stat)
(pop3-uidl-dele):
* lisp/net/shr-color.el (shr-color-hue-to-rgb):
* lisp/play/5x5.el (5x5-up, 5x5-left):
* lisp/play/decipher.el (decipher-read-alphabet, decipher--digram-total)
(decipher-analyze-buffer):
* lisp/play/hanoi.el (hanoi-insert-ring, hanoi-move-ring):
* lisp/profiler.el (profiler-format-number)
(profiler-calltree-build-unified):
* lisp/progmodes/antlr-mode.el (antlr-next-rule, antlr-indent-line):
* lisp/progmodes/c-ts-common.el (c-ts-common-statement-offset):
* lisp/progmodes/ebrowse.el
(ebrowse-cyclic-display-next/previous-member-list):
* lisp/progmodes/hideif.el (hif-backward-comment):
* lisp/progmodes/js.el (js-beginning-of-defun, js-end-of-defun)
(js-ts--syntax-propertize):
* lisp/progmodes/typescript-ts-mode.el
(tsx-ts--syntax-propertize-captures):
* lisp/rect.el (rectangle--*-char):
* lisp/term.el (term-emulate-terminal):
* lisp/textmodes/reftex-cite.el (reftex-do-citation):
* lisp/textmodes/reftex-index.el (reftex-index-next-phrase):
* lisp/textmodes/reftex-parse.el (reftex-init-section-numbers):
* lisp/textmodes/reftex-sel.el (reftex-select-unmark):
* lisp/textmodes/reftex.el (reftex-silence-toc-markers):
* lisp/treesit.el (treesit-navigate-thing):
* lisp/vc/diff-mode.el (diff-sanity-check-context-hunk-half,
(diff-sanity-check-hunk):
* lisp/vc/pcvs-util.el (cvs-first):
* lisp/vc/smerge-mode.el (smerge-get-current):
* lisp/vc/vc-hg.el (vc-hg--glob-to-pcre):
* test/lisp/net/socks-tests.el
(socks-tests-perform-hello-world-http-request):
* test/src/buffer-tests.el (test-overlay-randomly): Prefer decf to
cl-defc in all code where we can.