4.14.0 regression: key inputs get duplicated in screenReader mode

[martinpitt]

When enabling screenReaderMode: true, typing any character into the terminal gets duplicated. This happens in cockipt-podman, but reproduces in xterm's own builtin demo.

Details

• Browser and browser version: Firefox 91, Chromium 90.0.4430.212
• OS version: Fedora 34
• xterm.js version: happens with yesterday's 4.14.0 version, any earlier version was fine.

Steps to reproduce

1. Start the demo: npm run start, open http://127.0.0.1:3000/
2. Type cat /etc/os-release into the terminal; this works
3. Enable "screenReaderMode" in the options. Now typing "cat" ends up as "ccaatt". The terminal really receives two keystrokes, as the shell complains about "ccaatt: command not found".

[Tyriar]

Might be caused by #3429

[Tyriar]

_inputEvent is triggering the data event a second time but only when screen reader mode is on:

[Tyriar]

xterm.js/src/browser/Terminal.ts

Lines 1090 to 1096 in 9c49b31

	// Cancel events when not in screen reader mode so events don't get bubbled up and handled by
	// other listeners. When screen reader mode is enabled, this could cause issues if the event
	// is handled at a higher level, this is a compromise in order to echo keys to the screen
	// reader.
	if (!this.optionsService.options.screenReaderMode) {
	return this.cancel(event, true);
	}

[martinpitt]

Thanks a lot @Tyriar for the super-fast fix! I confirm this works properly again with 4.14.1.