Reproduced on device: open a file, scroll, long-press-highlight a
word, then recents-wipe the app ~1s after the highlight. The session
file held the file but lost the selection and cursor: the 1s
rate-limit had not elapsed since the previous save, so the final
changes never flushed before the process died (a recents-wipe is a
kill, not a clean shutdown, so Shutdown's final save never runs).
Two changes in saveSessionIfChanged:
- Urgent path: save immediately when the file changes or a selection
appears/vanishes. These are low-frequency, high-value changes
(the user just opened a file or highlighted/cleared text), and they
are exactly what 'where I left off' means.
- sessionSaveInterval 1s -> 250ms: bounds how stale scroll/cursor can
be at an unlucky kill. The file is a few hundred bytes, so a few
small writes a second during active scrolling is negligible.
TestRestore_UrgentSaveOnSelection drives the kill race: a selection
made right after the file-open save must land in the saver without
waiting out the interval (fails with the urgent path disabled).
Greg Pomerantz
2eb18b5c70