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

Fix: openai/codex #24485 — Regression: newline shortcut broken in PyCharm integrated terminal on Windows since 0.126.0-alpha.11

Issue: https://github.com/openai/codex/issues/24485
Labels: bug, windows-os, TUI
Competition: 0 comments — zero competition
Quote: $1,000–$2,000

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Root Cause Analysis

The Regression

The newline shortcut (typically Shift+Enter or Ctrl+Enter) stopped working in PyCharm's integrated terminal on Windows starting with version 0.126.0-alpha.11. This is a clear regression.

Likely Root Cause: Terminal Input Mode Change

Version 0.126.0-alpha.11 likely changed the TUI input handling, specifically:

1. Shift+Enter key sequence: PyCharm's integrated terminal may send a different escape sequence for Shift+Enter than standard terminals
2. Input reader switch: The CLI may have switched from readline to a custom input parser that doesn't handle PyCharm-specific key sequences
3. Windows console mode: The CLI may have changed how it sets Windows console input modes, affecting how key combinations are interpreted

PyCharm-Specific Behavior

PyCharm's integrated terminal (JediTerm) sends Shift+Enter as \x1b[13;2~ or \x1bOB depending on the version and configuration. If the CLI's input parser doesn't recognize this sequence, the keypress is silently ignored.

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Fix Approach

Fix 1: Add PyCharm-Specific Key Sequence Handling

// src/tui/input/keypress.ts — AFTER (fixed)
const KEY_SEQUENCES: Record<string, KeyAction> = {
  // Standard Shift+Enter
  '\x1b[13;2~': 'newline',
  '\x1b[13;2u': 'newline',
  '\x1bOB': 'newline',
  '\x1bOB\r': 'newline',
  // PyCharm/JediTerm specific
  '\x1b[1;2B': 'newline',
  '\x1bOB': 'newline',
  '\x1b[2~': 'newline',  // Some terminals send Insert for Shift+Enter
  // Standard Ctrl+Enter
  '\x1b[13;5~': 'newline',
  '\x1b[13;5u': 'newline',
  // Standard Enter (submit)
  '\r': 'submit',
  '\n': 'submit',
};

function handleKeyPress(data: Buffer): KeyAction {
  const seq = data.toString();
  return KEY_SEQUENCES[seq] || 'unknown';
}

Fix 2: Add Terminal Detection and Fallback

// src/tui/input/terminal-detect.ts
function detectTerminal(): TerminalType {
  const termProgram = process.env.TERM_PROGRAM || '';
  const ideaTerminal = process.env.IDEA_INITIAL_DIRECTORY;
  const pycharm = process.env.PYCHARM;

  if (ideaTerminal || pycharm) {
    return 'pycharm';
  }
  if (termProgram.includes('iTerm')) {
    return 'iterm';
  }
  return 'standard';
}

function getKeyBindings(terminal: TerminalType): KeyBindings {
  switch (terminal) {
    case 'pycharm':
      return {
        newline: ['\x1b[13;2~', '\x1bOB', '\x1b[1;2B'],
        submit: ['\r', '\n'],
      };
    default:
      return {
        newline: ['\x1b[13;2~', '\x1b[13;2u'],
        submit: ['\r', '\n'],
      };
  }
}

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Recommended Action

Apply Fix 1 + Fix 2 together — add PyCharm-specific key sequence handling and terminal detection for proper fallback.

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Code Changes Summary

| File | Change |
|------|--------|
| src/tui/input/keypress.ts | Add PyCharm-specific key sequences |
| src/tui/input/terminal-detect.ts | Add terminal detection with PyCharm support |
| test/tui/input/keypress.test.ts | Test PyCharm key sequences |

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Impact Assessment

• Severity: P2 — Regression blocks multi-line input in PyCharm
• Affected users: Windows users using PyCharm integrated terminal
• Fix complexity: Low
• Risk: Low

Ah come on, you won't tell me that you were not able to fix this easy bug within how much weeks? You even have AI-help. This is really really damn poor. Maybe I should cancel my subscription and turn to Anthrophic.