* test/src/buffer-tests.el (get-pos-property-overlay-beg): New test.
(get-pos-property-overlay-empty-rear-advance): ditto.
(get-pos-property-overlay-past-rear-advance): ditto.
(get-pos-property-overlay-at-narrowed-end): ditto.

See bug#58703.

* src/buffer.c (overlays_in): Add a new TRAILING arg expressing the
behavior wanted by `overlays-at', namely to include all overlays
beginning at the POS passed to `overlays-at', even if POS is the end
of the narrowed region.  Pass true and the search range is extended to
ZV+1 if END is greater than ZV, just as is done for EMPTY.
(overlays_at): Pass 'true' for the new trailing arg.  At present this
is the only caller passing 'true'.
(mouse_face_overlay_overlaps): Pass 'false' for the new trailing arg.
(disable_line_numbers_overlay_at_eob): ditto.
(Foverlays_in): ditto.
* src/editfns.c (overlays_around): ditto.
* test/src/buffer-tests.el (sorted-overlays): Add a spot test for
this.

When passed EMPTY, 'overlays_in' should return empty overlays at END.
It was doing so, but it was also returning any other overlay that
happened to begin at END.

bug#58672

* src/buffer.c (overlays_in): Don't return overlays at END unless they
are empty overlays.
(disable_line_numbers_overlay_at_eob): Pass 'false' instead of 'NULL'
for the bool 'empty' arg.
* test/src/buffer-tests.el (sorted-overlays-in): New helper function.
(test-overlays-in-empty-range): New test exhaustively covering these
edge conditions.
(test-overlays-in-empty-range-bug58672): Simple test for one case.

Correct `get-char-property` which failed to ignore empty overlays.

* src/textprop.c (get_char_property_and_overlay): Make sure the
overlay covers the character.
* test/src/buffer-tests.el (buffer-tests--overlay-bug58479): New test.
* src/buffer.h (buffer_has_overlays): Avoid `interval_tree_size`.

* lisp/progmodes/hideshow.el
(hs-find-block-beginning-match): New function to be used in
`hs-already-hidden-p'.
(hs-already-hidden-p): Add check if beginning of line is inside a
block.
(hs-toggle-hiding): Don't change to selected-window's buffer when
event arg is absent.

* test/lisp/progmodes/hideshow-tests.el
(hideshow-tests-with-temp-buffer-selected): New helper macro.
(hideshow-tests-make-event-at): New helper function.
(hideshow-already-hidden-p-1): New test.
(hideshow-toggle-hiding-1): New test.
(hideshow-mouse-toggle-hiding-1): New test (bug#52092).

* lisp/thumbs.el:
* test/lisp/thumbs-tests.el: Move from here...
* lisp/obsolete/thumbs.el:
* test/lisp/obsolete/thumbs-tests.el: ...to here.  (Bug#57779)

Make cconv.el detect when a closure's interactive form needs to
capture variables from the context and tweak the code accordingly
if so.

* lisp/emacs-lisp/cconv.el (cconv--interactive-form-funs): New var.
(cconv-convert): Handle the case where the interactive form captures
vars from the surrounding context.  Remove left over handling of
`declare` which was already removed from the cconv-analyze` phase.
(cconv-analyze-form): Adjust analysis of interactive forms accordingly.

* lisp/emacs-lisp/oclosure.el (cconv--interactive-helper): New type and
function.
* lisp/simple.el (function-documentation, oclosure-interactive-form):
Add methods for it.

* test/lisp/emacs-lisp/cconv-tests.el
(cconv-tests-interactive-closure-bug51695): New test.