With local echo on, committed text sits in the LocalEchoOverlay and does not
reach the PTY before Enter, so the PTY cursor that places the preview span
stays at the prompt start. The span's z-index 6 only counts inside
.xterm-helpers (its own z-index 5 stacking context), and the overlay is a
z-index 7 layer whose first line is opaque from the prompt column, so every
composition after the first one in a prompt was drawn under the overlay.
- xterm-zerolag-input: add setComposition(text) and a composition getter.
The overlay draws the composition as an underlined, aria-hidden tail after
its pending text, through the same wrapping and grow-upward layout. It is
never part of pendingText, hasPending or anything sent; clear() and
removeChar() drop it, and rerender()/refreshFont() keep it.
- terminal-ui.js: while local echo shows typed text (on, and not handed back
to PTY echo by a nav key), render and clear the preview through
setComposition. The helper span stays for local echo off, and as the
fallback when the overlay cannot place the text (no prompt found).
- Browser test against real xterm 6, the overlay bundled from its source
and styles.css: a second composition after pending text is the topmost
element after that text, and the commit lands in the overlay once. Unit
tests for setComposition in the package and for the routing in the
structure test.
- CLAUDE.md and architecture-invariants: state the preview's effective layer.
- Observe keydown in the capture phase on terminal.element, an ancestor of
the helper textarea, so the controller sees it before xterm's own capture
listener finalizes the composition and emits the commit through onData.
Finalize on exactly the keys CompositionHelper.keydown does (every keyCode
except 20/229/16/17/18), ignoring isComposing and key as xterm does.
- Bound awaitingCommit with the same 2 s fallback as the committed phase, so
a composition whose commit never reaches onData cannot turn the next
unrelated keystroke or paste into an IME commit.
- pagehide resets the controller instead of destroying it, so a back-forward
cache restore keeps the preview working.
- Give the preview an opaque background from the terminal theme.
- Route an IME commit through the ordinary printable/paste local echo branch
and complete the commit afterwards; drop the send-on-throw fallback.
- Pin the event order with an xterm stand-in registered in the capture phase
ahead of the controller, and against real xterm in a browser test.
- CLAUDE.md: note the IME commit routing and the z-index 6 preview layer.
Aamer Akhter