BLOCKER #1: accessibilityUpdating flag exception safety.
A Lisp signal (longjmp) during postAccessibilityUpdates left
the re-entrance flag permanently YES, suppressing all future
AX notifications → VoiceOver goes silent randomly.
Fix: specpdl unwind protection (record_unwind_protect_ptr)
resets the flag on any longjmp. All 3 exit points use unbind_to.
BLOCKER #2: static struct buffer *lastBuffer dangling pointer.
Raw C pointer to buffer struct has no GC protection. After
kill-buffer, the pointer dangles.
Fix: file-scope Lisp_Object lastChildFrameBuffer with staticpro.
EQ comparison instead of pointer equality.
Also: revert accidental em-dash → triple-dash in title bar (0007),
fix README factual error (BUF_OVERLAY_MODIFF cache key).
hl-line-mode (and similar) bumps BUF_MODIFF via text property
changes on every cursor movement. The else-if structure caused
the modiff branch to fire (skipping ValueChanged correctly) but
also blocked the cursor-move branch (SelectedTextChanged).
Fix: use textDidChange flag to decouple the two branches.
ValueChanged and SelectedTextChanged remain mutually exclusive
for real edits, but SelectedTextChanged now fires when only
text properties changed.
Added: child frame buffer scanning for Corfu/Company-box.
Fixed: Zoom rect at text area left edge (not window center).
Added: 'selection' face match for company-tooltip-selection.
Zoom rect now at text area left edge (WINDOW_TEXT_TO_FRAME_PIXEL_X)
with cursor-width (FRAME_COLUMN_WIDTH) instead of full window width.
Face matching adds 'selection' (company-tooltip-selection).
Zoom now tracks the selected candidate row via overlayZoomRect
instead of always pointing at the text cursor. Returns to cursor
on typing (chars_modiff change).
Previous two-reference algorithm failed because:
- Vertico's cursor-space line (face=nil) confused the reference
- Count overlay processed before candidates overlay
- Group titles have distinct faces too
New approach: ns_ax_face_is_selected checks if face symbol name
contains 'current' or 'selected'. Works for all major frameworks
(Vertico, Icomplete, Ivy) without framework-specific code.
Key changes from previous version:
- Remove overlay text from ns_ax_buffer_text (was causing spurious
'new line' announcements via VoiceOver text diff)
- Do NOT invalidate text cache on overlay change
- Two-reference face detection (handles selected at any position)
- SDATA scan instead of per-char Faref for newline detection
- Zoom tracking via UAZoomChangeFocus for selected candidate row
- Deduplication via cachedCompletionAnnouncement
