Commit 4c34eeb416 stopped pushing the Kitty keyboard protocol (CSI >1u)
because Ctrl+C arrived as ESC[99;5u instead of \x03, breaking SIGINT.
But modifyOtherKeys level 2 (CSI >4;2m) was kept so Shift+Enter stays
distinguishable from Enter.
Under modifyOtherKeys=2, terminals re-encode EVERY Ctrl+key combo as
ESC[27;5;<codepoint>~ instead of the raw control byte. prompt_toolkit
3.x only maps ESC[27;5;13~ (Ctrl+Enter = Ctrl+M); all other Ctrl+letter
combos are unmapped and leak as literal text or get swallowed — breaking
Ctrl+A, Ctrl+C, Ctrl+D, Ctrl+E, Ctrl+K, Ctrl+R, Ctrl+U, Ctrl+W, Ctrl+Z,
etc. Shift+letter combos (ESC[27;2;<codepoint>~) have the same problem,
causing the 'caps locked sessions' symptom where typed text appears
corrupted or stuck.
Fix: add install_modify_other_keys_aliases() to pt_input_extras.py that
populates prompt_toolkit's ANSI_SEQUENCES dict with 294 mappings covering:
- Ctrl+letter (a-z): ESC[27;5;<code>~ and ESC[<code>;5u -> Keys.ControlA..Z
- Ctrl+digit (0-9): same formats -> Keys.Control0..9
- Ctrl+symbol ([ \ ] ^ _ @ Space): same formats -> matching Keys.Control*
- Alt+letter (a-z, A-Z): both formats -> (Escape, <letter>) tuple
- Shift+letter (a-z, A-Z): both formats -> uppercase character
Uses setdefault semantics — never clobbers existing mappings from
install_shift_enter_alias or install_ctrl_enter_alias. The Ink TUI
(Node.js) already handles this via a regex parser; prompt_toolkit 3.x
uses dict lookup only, so we populate the dict.
Refs #56684, #87711.
kshitij
b353ac39a2