Task 19. SS5b wired Absent and left the other four transitions armed,
inert while nothing consumed the latch and defects the moment
cancellation gained an effect.
Three are visible in the producer, where the declaration is built: the
side WINDOW replaced, its BUFFER replaced, and the GEOMETRY epoch moved.
The last needed a retained geometry_epoch on PanelPresentation, because
nothing else the producer holds moves with a same-size geometry change
--- not the panel epoch, not the identity, and on a legacy peer not a
mapping key either --- so the transition was invisible and a live gesture
survived a grid it no longer belonged to. DETACH cancels in the
dispatcher, before any teardown, because it is the transition with no
later opportunity of any kind.
The release follows the RECORDED domain, so a buffer replacement pays
the child the gesture was pressed on rather than whatever occupies the
panel now.
G5b(a)-(d), G5m and G5j, each reading the child's byte stream or the
document's selection rather than the latch. The mutations discriminate
exactly: dropping the window half of the identity check fails only the
buffer leg, dropping the buffer half fails only the window leg, dropping
the geometry check fails only that leg, and dropping detach's cancel
fails only detach.
G5m survives all four, and correctly --- two coincident causes take the
same latch, so one release, and removing either cause still leaves one.
G5j's two legs differ and the row proves it: an empty selection is
cleared without moving point, while a real dragged region survives
anchor-and-cursor exact. Clearing every selection fails the second leg,
which is the mutation that matters --- ending a gesture is not a reason
to discard what the user selected.
Machine note: a foreign java build was running at 213% CPU during this
work, and the wall-clock budget row composition_overhead_under_ten_percent
redded twice under it, green in isolation both times. Functional rows
are unaffected; the gate should wait for a quiet machine.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
e2b080f6ae