🔥 Regression: newline shortcut no longer works in PyCharm integrated terminal on Windows since 0.126.0-alpha.11

What version of Codex CLI is running?

bisect versions

What subscription do you have?

irrelevant

Which model were you using?

irrelevant

What platform is your computer?

Microsoft Windows NT 10.0.19045.0 x64

What terminal emulator and version are you using (if applicable)?

PyCharm, "Classic" and "Reworked 2025"

What issue are you seeing?

After upgrading the npm-installed Codex CLI from 0.126.0-alpha.10 to 0.126.0-alpha.11, inserting a newline in the TUI composer no longer works in the PyCharm integrated terminal on Windows.

The same shortcut/input still works in normal Windows shell / PowerShell, and downgrading to 0.126.0-alpha.10 fixes the issue.

What steps can reproduce the bug?

Steps to reproduce:

1. Install npm i -g @openai/codex@0.126.0-alpha.11
2. Open PyCharm integrated terminal
3. Run codex
4. Type a multi-line prompt
5. Try inserting a newline using the usual newline shortcut (ctrl+j, shift+enter, alt+enter, ctrl+m)
6. Observe that no newline is inserted / behavior differs from 0.126.0-alpha.10

What is the expected behavior?

The newline shortcut should insert a newline in the composer, as in 0.126.0-alpha.10.

Additional information

Actual:
No newline is inserted in PyCharm integrated terminal.

Regression range:
Works: 0.126.0-alpha.10
Broken: 0.126.0-alpha.11 (until tested version: 0.129.0-alpha.4)

config.toml contains:
<pre>
[tui.keymap.editor]
insert_newline = ["ctrl-j", "ctrl-m", "shift-enter"]
</pre>

Likely related change:
0.126.0-alpha.11 includes PR #18593, which rewired TUI input handling through the new runtime keymap. The commit fix(tui): honor remapped submit keys removed the legacy Enter/Tab submission fallback. This likely changed how modified Enter events from JetBrains terminals are routed.

Suggested fix:
Ensure modified Enter variants emitted by JetBrains integrated terminals are mapped to editor.insert_newline, or preserve the old textarea fallback for Enter events with unsupported/non-submit modifiers.

Potential regression test:
Add a composer test that simulates the JetBrains/PyCharm Enter-with-modifier event and verifies:

• it inserts a newline
• it does not submit the composer

AND NO, THIS IS NO DUPLICATE AND STILL NOT FIXED!