Follow-up to the salvaged #88097: the same normalization covers the
Shift+letter class reported in #92343 (xterm modifyOtherKeys and both
kitty CSI-u codepoint forms), plus a guard that plain ASCII typing
never triggers the ESC-prefix predicate.
Follow-up to the salvaged #89676 + #90291 lock-bit fixes: extract a shared _lock_variants() helper and cover the sites both PRs missed - install_shift_enter_alias / install_ctrl_enter_alias / install_cmd_backspace_alias CSI-u spellings, legacy CSI-letter and CSI-tilde navigation twins derived from the existing table for ALL modifiers 1-16 (not just plain/shift), plain F1-F4 SS3 fallback, unmodified CSI-u keys (Tab/Enter/Space/Backspace), and kitty PUA functional keys (keypad, F13-F24, Ignore range) under lock bits. 8 new tests.
kitty and ghostty OR the CapsLock (64) / NumLock (128) state into the
CSI-u modifier parameter. With NumLock on, Ctrl+C arrives as
ESC[99;133u (5 + 128) instead of ESC[99;5u; the alias table had no
entry for it, so every key combo leaked as literal text like
[127;133u (#89651). Install every CSI-u alias with the lock-bit
variants (+64/+128/+192); the xterm modifyOtherKeys encoding never
carries lock bits, so the ESC[27;N;CP~ form is left untouched. The
Esc-key registration now covers modifier 1 as well (1+128=129 is a
lone Esc with NumLock on).
Commit 4c34eeb416 fixed dead Ctrl+C by removing the Kitty protocol push
(CSI >1u) from _EXTENDED_ENTER_KEYS_SEQ, keeping only modifyOtherKeys
level 2. That regressed kitty-the-terminal completely: kitty removed
xterm modifyOtherKeys support (kovidgoyal/kitty#4075) and only speaks
its own protocol, so after the removal kitty users lost Shift+Enter and
every other extended key — the CSI >4;2m we still pushed is a no-op
there (kitty even logs a PARSE ERROR for it).
The original reason for removing the push is obsolete: #87511 mapped
CSI-u control sequences, so Ctrl+C as ESC[99;5u now parses to
Keys.ControlC and fires the existing c-c binding. (The kernel-INTR
concern in that commit was moot — prompt_toolkit's raw mode clears
ISIG, so Ctrl+C is always handled by the binding, never the kernel.)
Restore the dual push (CSI >1u + CSI >4;2m), exactly mirroring the Ink
TUI, and complete the alias table for what the kitty disambiguate flag
actually emits — #87511 left real gaps, some of which its PR body
wrongly claimed were covered:
- Esc key: ESC[27u (+ modifiers) — previously leaked '[27u' as text
- Ctrl+Backspace -> backward-kill-word (#78285 was closed on the wrong
claim that codepoint-127 mapping existed; it did not)
- Shift+Space -> space (#86866's second symptom; the Ctrl+Space
mapping never covered modifier 2)
- Alt+Enter -> newline tuple; Shift+Tab -> BackTab; Ctrl+Tab -> Tab;
Alt/Shift+Backspace
- Multi-modifier letters (Shift+Alt 4, Ctrl+Shift 6, Ctrl+Alt 7,
Ctrl+Alt+Shift 8) normalized onto their Ctrl/Escape-prefix targets,
both unshifted (kitty) and shifted (mok emitters) codepoints
- Kitty PUA functional keys: keypad -> non-keypad equivalents,
F13-F24, and Ignore for lock/media/modifier-event keys so they are
consumed instead of leaking (kitty emits these even in legacy mode)
Also: clear the VT100 parser's prefix cache after installing (stale
answers could misparse), and re-push extended keys after
_recover_terminal_input_modes' reset — the recovery previously popped
both modes mid-session and never re-enabled them, silently killing
Shift+Enter until restart.
Refs #87511, #87074, #56684, #56645, #78285, #86866, #87390.
Apply findings from /simplify-code 3-agent review:
1. Extract _install_paired() inner helper — the Ctrl, Alt, and Shift
sections all repeated the same mok+csiu sequence generation pattern
(~30 lines of duplication). Now each section builds a dict and
delegates to _install_paired(modifier, mapping).
2. Replace 10 hardcoded Ctrl+digit lines with a loop matching the
Ctrl+letter pattern above it.
3. Fix misleading comment: claimed 'Ctrl+0 doesn't produce a control
byte' but chr(ord('0') & 0x1F) = 0x10 = ControlP. The code was
correct (maps directly to Keys.Control0..9); only the comment was
wrong.
4. Add comment explaining why Shift+letter maps both lowercase and
uppercase codepoints (some terminals send the already-shifted
codepoint with modifier=2).
5. Test fixture: snapshot/restore ANSI_SEQUENCES in teardown so 294
mappings don't leak into sibling test files (global mutable state).
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.
Teknium