Selecting text near the left edge on a touch browser could page back
instead: a long-press released just inside the 500ms tap window (Android
selection engages at ~400-500ms, right at the guard boundary) or landing
on a margin resolved as a tap, armed the 280ms debounce, and nothing
ever cancelled it. Four hardenings in the tap-zone pipeline:
- contextmenu (Android's long-press-engaged signal) suppresses the
matching pointerup from counting as a tap, closing the duration race
- pointercancel (the browser taking over the gesture) now resets the
tracked pointer so stale state can never match a later touch
- selectionchange on the host document and every content iframe cancels
an armed tap action: a selection appearing right after finger-lift
means the 'tap' was a long-press selection engaging
- the host-viewport pointerup honors the tracked any-selection flag,
closing the blind spot where selections in iframes or the host's own
fixed-layout text layer were invisible to the host surface (the
per-surface check only ran for iframe docs)
Purely touch-path (coarse pointer) changes; desktop behavior untouched.
john-okeefe
905218dd4b