xterm parses write() data after chunkedTerminalWrite has already cleared
_isLoadingBuffer, so the main terminal's replay gate never held: a tab switch
or reconnect re-copied the newest OSC 52 in the replayed history. Strip every
OSC 52 from the replay beside the DEC 2026 markers (OSC52_STRIP_RE). Tiles
keep their own _bufferLoading gate, which holds there.
One Claude Code copy arrives up to three times (its own OSC 52, tmux
load-buffer -w, set-clipboard forwarding), so identical text within
OSC52_DEDUPE_MS is dropped. The manual-copy fallback opens only in the
focused tab, so a background tab on the same session stays quiet.
The replay tests now drive the real chunkedTerminalWrite into
@xterm/headless and fail without the strip. Test harnesses that supply
DEC_SYNC_STRIP_RE by hand get OSC52_STRIP_RE too, and CLAUDE.md records
the rules next to Auto Copy.
App Settings > Terminal & Input > Selection & clipboard > Auto Copy
Selection (`autoCopySelection`, per-device, default OFF). With it on,
highlighting text in the terminal copies it: mouse drag, double-click
word, triple-click line, and the phone long-press selection. Ctrl+C is
untouched and still copies on demand.
Three things decide the shape of it:
* It fires at the END of a gesture, never in onSelectionChange. That
callback runs for every cell a drag crosses, so copying there would be
one clipboard write per mouse move. It only arms a pending flag; a
document-level mouseup listener flushes, and the touch path calls the
flush itself because it preventDefaults its touchend and no mouseup
ever arrives there.
* The flush is synchronous inside the handler, because both clipboard
paths need user activation: Firefox gates navigator.clipboard
.writeText on it, and execCommand('copy'), the fallback the plain-HTTP
LAN install lands on, has to run in the gesture's own task. A timer or
a wait for onSelectionChange loses it, invisibly in Chrome.
* It deliberately does NOT do what copyTerminalSelection() does. That
one clears the selection (so a second Ctrl+C is an interrupt) and
focuses the terminal. Clearing would make text vanish under the cursor
that just highlighted it, and focusing opens the on-screen keyboard
over it on a phone. Focus is instead restored to whatever held it,
which only matters for the execCommand fallback.
Guards are pure in decideAutoCopy() (constants.js): off, blank or
whitespace-only text, and a 1M-char cap, since a drag off the top of the
viewport autoscrolls and one gesture can sweep the whole 50k-line
scrollback. Past the cap the copy is refused rather than truncated, with
a toast pointing at Ctrl+C.
Feedback is silent on success except once per page load, so a feature
that works by doing nothing visible can still be told from a dead
toggle; failures and refusals toast, throttled to 10s.
Per-device on both counts the settings rule requires: in `displayKeys`
and absent from the .strict() SettingsUpdateSchema, because clipboard
access differs by device and by origin.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Zoltan Zombory