Native Windows, WSL, SSH sessions, and Windows Terminal all send
Ctrl+Enter as bare LF (c-j). Hermes was binding c-j as submit on
every POSIX platform, so Ctrl+Enter submitted instead of inserting
a newline on those terminals. Reported in #22379.
Add _preserve_ctrl_enter_newline() predicate that detects the
environments where Ctrl+Enter must produce a newline (sys.platform
== 'win32', SSH_CONNECTION/SSH_CLIENT/SSH_TTY env, WT_SESSION,
WSL_DISTRO_NAME, /proc/version 'microsoft' marker). Gate the
c-j-as-submit binding off in those environments and gate the
c-j-as-newline handler on. Local POSIX TTYs without those markers
(docker exec, plain ssh from a Mac) keep c-j as submit so plain
Enter still works on thin PTYs.
Add install_ctrl_enter_alias() in hermes_cli/pt_input_extras.py
mapping the three CSI-u / modifyOtherKeys variants of Ctrl+Enter
('\x1b[13;5u', '\x1b[27;5;13~', '\x1b[27;5;13u') to the
(Escape, ControlM) tuple Alt+Enter produces. This lets Kitty /
mintty / xterm-with-modifyOtherKeys users over SSH get a Ctrl+Enter
newline through the existing Alt+Enter handler.
9 new tests + extended existing test_lf_enter_binds_to_submit_handler_posix
to cover bare-local vs SSH branches.
Closes#22379.
Closes#5346.
Most terminals send the same byte sequence for `Enter` and `Shift+Enter`
by default, so the application can't tell them apart — this is a terminal
protocol limitation, not something Hermes can paper over. But terminals
that implement the Kitty keyboard protocol (Kitty / foot / WezTerm /
Ghostty by default; iTerm2 / Alacritty / VS Code terminal / Warp once the
protocol is enabled) DO emit a distinct sequence for `Shift+Enter`:
- `\x1b[13;2u` — Kitty / CSI-u, modifier=2
- `\x1b[27;2;13~` — xterm modifyOtherKeys=2
Stock prompt_toolkit doesn't have the CSI-u sequence in its
`ANSI_SEQUENCES` table at all, and it maps the modifyOtherKeys variant to
plain `Keys.ControlM` (Enter) — i.e. it strips the Shift modifier, which
is the bug users actually hit on iTerm2 and friends.
This PR adds `hermes_cli/pt_input_extras.install_shift_enter_alias()`,
called once at CLI startup from `cli.py`, which inserts/overwrites those
sequences in `ANSI_SEQUENCES` so they decode to `(Keys.Escape, Keys.ControlM)`
— the same key tuple `Alt+Enter` produces. The existing Alt+Enter newline
handler (`@kb.add('escape', 'enter')` in `cli.py`) then fires unchanged,
so there is no new keybinding to register and no behavioral change for
terminals that don't emit the distinct sequences.
Files
=====
* `hermes_cli/pt_input_extras.py` — new module hosting the helper. Lives
outside `cli.py` so it's importable in tests without dragging in the
full CLI runtime (which depends on `fire`, `rich`, etc.).
* `cli.py` — calls `install_shift_enter_alias()` once at module import.
Wrapped in try/except so prompt_toolkit version drift can't break CLI
startup.
* `tests/cli/test_cli_shift_enter_newline.py` — 6 tests:
- registration of all three byte sequences
- overwrite of stock prompt_toolkit's broken modifyOtherKeys mapping
- idempotency
- parser equivalence: CSI-u Shift+Enter == Alt+Enter
- parser equivalence: modifyOtherKeys Shift+Enter == Alt+Enter
- plain Enter remains a single key (submit), distinct from the two-key
Alt+Enter / Shift+Enter tuple
* `website/docs/user-guide/cli.md` — keybinding table updated; new
"Shift+Enter compatibility" subsection with a per-terminal status table
noting macOS Terminal / stock Windows Terminal cannot distinguish the
keystroke at the protocol level.
* `website/docs/getting-started/quickstart.md`,
`website/docs/guides/tips.md` — short mention pointing readers at the
full compatibility note in `cli.md`.
Tested
======
pytest tests/cli/test_cli_shift_enter_newline.py # 6 passed
Live-tested by triggering `\x1b[13;2u` against the running Vt100Parser
(see test). Not exercised in a real terminal end-to-end because that
requires a Kitty-protocol-capable host; the test exercises the parser
path that drives the live terminal too.
