macOS occlusion tracking can wedge document.visibilityState at 'hidden'
after display sleep and never fire another visibilitychange. The hidden-
delivery gate then keeps dropping renderer-bound bytes for panes the user
is looking at (field snapshot 2026-07-06, v1.4.124-rc.2.perf: 78MB dropped
across 2 pane-level-visible ptys with a fully healthy transport), and every
recovery path (window focus, system-resume relay, backlog recovery) re-ran
syncHiddenRendererPtyDelivery only to recompute the same stale predicate —
nothing could ever clear the gate. The user sees a frozen terminal; typing
echo is dropped in main; only a reload recovers.
Real user input while the document claims hidden is a physical
contradiction: keystrokes and clicks only reach a focused, on-screen
window. stale-document-visibility.ts latches that proof, runs each pane's
existing visibilitychange resync (gate unhide + hidden-output snapshot
restore), and hands authority back to the occlusion tracker on the next
genuine visibilitychange. No timers; the failure bias is safe — a wrong
latch can only restore pre-gate delivery cost, never drop bytes. Hot path
unchanged: the foreground predicate still returns on the same single
comparison while the document is visible.
tests/e2e/terminal-stuck-occlusion-recovery.spec.ts pins the wedge
(visibilityState pinned hidden -> output dropped, not painted; the
hiddenDeliveryGatedVisiblePtyCount field discriminator reads >0) and the
recovery (one Shift keypress repaints the missed output from the main-owned
snapshot, no reload, while visibilityState still reads hidden). Negative
control verified: the spec fails without this fix. Typing-latency perf
gate passes; terminal-pane unit suites 366/366.
Co-authored-by: Orca <help@stably.ai>
Jinwoo-HandOrca
fd5c0f643f