The 1.12.0 retest on #205 reported it still broken in two shapes: a wheel that
did nothing at all on Firefox/macOS (while Fn+Up paged back through intact
text), and iPhone history that went back a little, repeated blocks and got
worse the further up it went. Both come from a Claude pane's LOCAL buffer being
hollow: tmux keeps no history for a repaint-mode pane (history_size 0), so
xterm holds only replayed repaint frames.
1. The scroll-to-top full=1 re-pull now refuses a DOWNGRADE. It resets the
terminal and rewrites it from the capture, which is a win when tmux holds
more than the browser, but for a repaint-mode pane that capture is roughly
ONE frame and the rewrite deleted history mid-scroll. Measured A/B on a live
pane, same gesture: guard off collapses 341 rows to 42, guard on preserves
all 341. _replayWouldShrinkBuffer() estimates the capture's rendered rows
(escapes stripped, capture-pane -J re-wrapping accounted for) and skips the
rewrite when it is more than one screen short; a refused session's cooldown
goes from 4s to 60s so a hollow pane stops re-fetching megabytes.
2. A false forwarding gate on a Claude session no longer means a dead gesture.
Under a triple guard (claude mode, gate false, baseY 0), wheel and touch
travel becomes coalesced PageUp/PageDown through the same 40ms queue as the
SGR reports, at half a screen of travel per page key. Shift is excluded: it
keeps meaning "local scrollback".
3. getClaudeCliVersion() no longer caches FAILURE. It stored null on any
exception and guarded on !== undefined, so one timed-out or PATH-starved
probe at the first Claude session start disabled wheel-forwarding for every
Claude session until the server restarted, which fits a report of breakage on
phone, tablet and laptop at once. Success is still cached for the process
lifetime; failures retry with a 1/2/4 up to 15min backoff, and the policy is
a pure function so the semantics are testable without spawning claude.
4. The terminalWheelLocalScrollback footgun is handled by pairing rather than
scoping: the setting keeps meaning exactly what it says, and fix 2 catches
the case where "local" is empty. The App Settings tooltip now says to leave
it off for Claude/Codex sessions.
5. _logScrollRouting() prints one line per session per distinct decision:
forward-sgr / page-keys / local-scrollback / repull-refused-downgrade, with
mode, cliVersion, the opt-out state, mouse tracking and local scrollback
depth. #205 ran two rounds of remote guesswork over questions that line
answers directly.
Verified end to end against a real isolated instance (own data dir and tmux
socket) with real wheel events: forwarding still sends SGR reports, the opt-out
now sends real PageUp/PageDown where the wheel was dead, a tab-switch collapse
(401 rows to 44) is still fully recovered by the re-pull (back to 401), and a
seeded 341-row Claude buffer survives the same gesture that destroys it with the
guard disabled.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
