Neil d143922561 fix(terminal): deliver an IME commit the deferred textarea diff missed (#15198) ...

Picking a single Chinese character from the candidate window with a
number key loses it. The character flashes and disappears. Picking the
same candidate with the mouse works, and picking multi-character words
with number keys works.

Two paths can deliver an IME commit, and this falls between them. A
keydown the input method consumed routes into a setTimeout(0) diff of
the helper textarea, and that diff is what normally delivers the commit;
xterm's _keyDownSeen guard exists to defer to it. When the commit
arrives after that timer has already run, neither path delivers. Mouse
selection works because no key is down, and a real composition session
works because it takes a different path entirely. That narrows it to an
input method whose commit round-trips asynchronously and which shows no
in-application preedit.

Track that a consumed keydown still owes its commit, and deliver only
when the diff did not. The upstream guard and its single read site are
untouched, which is what keeps the duplicate-commit behaviour it was
added for sealed.

Not doing the obvious repairs deliberately: clearing the flag, skipping
it for keyCode 229, or setting it after the composition short-circuit
each unblock the input path without retiring the diff, and all three
were measured emitting the character twice.

The patch and the lockfile hash here are generated. Review
config/patches/xterm-src/@xterm__xterm@6.1.0-beta.287.src.patch, which
is the hand-written source of the change; the shipped patch and both
minified bundles are the regenerator's output from the pinned upstream
build, so nothing in this change was hand-transcribed into a bundle.

Refs xtermjs/xterm.js#6036
Closes #12099

2026-08-17 22:13:32 -07:00

..

@xterm__xterm@6.1.0-beta.287.src.patch

fix(terminal): deliver an IME commit the deferred textarea diff missed (#15198)

2026-08-17 22:13:32 -07:00