[Bug]: Backspace right after a "+ " list shortcut in the composer deletes the marker #31988

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

1. Keep Settings > Rich text composer on (the default).
2. In an empty composer, type + and then a space. The line turns into a bullet.
3. Press Backspace.

The same happens with * and 1. .

Expected behavior

Backspace right after the shortcut undoes it and leaves the typed + as plain text, so you can go on and send + something. The composer already does this for > and # .

Actual behavior

The bullet and the typed + both disappear, and the line is empty. Cmd+Z gives back only +, and the next space makes a bullet again. With rich text on, a line that starts with a literal + can't be typed.

Impact

Minor bug or occasional failure

Version or commit

0.1.8-nightly.20261105.4234, and main @ 6577c6b

Environment

macOS 27.2, T3 Code (Nightly) desktop app

Workaround

Turn off Settings > Rich text composer, or paste the text.

Cause

The list item's Backspace handler in apps/web/src/composer-rich-text-doc.ts (backspaceAcrossList) replaces Tiptap's default Backspace. The default runs undoInputRule first, and the replacement does not, so the new item is lifted out of its list instead.