Numpad keys not working in terminal TUI applications after 1.110 update (Electron 39 / Chromium 142 regression) #299374

Description

After updating to VS Code 1.110.0, numpad keys (0-9, Enter, decimal, operators) are not recognized by TUI applications running inside the integrated terminal. The numpad works correctly in the terminal shell itself before launching any TUI app.

Environment

• VS Code Version: 1.110.0 (system setup)
• Commit: 0870c2a
• Date: 2026-03-04T01:20:28.863Z
• Electron: 39.6.0
• Chromium: 142.0.7444.265
• OS: Windows_NT x64 10.0.26200
• Connection: Remote SSH to Ubuntu (ARM64)
• TUI Application: OpenCode (opentui-based)

Steps to Reproduce

1. Open VS Code 1.110.0
2. Open integrated terminal (local or Remote SSH)
3. Verify numpad keys work in the shell (they do)
4. Launch a TUI application that uses enhanced keyboard mode (e.g., OpenCode, or any bubbletea/opentui-based app)
5. Try typing numbers using the numpad
6. Observe: numpad keystrokes are completely ignored inside the TUI

Expected Behavior

Numpad keys should be recognized by TUI applications running in the integrated terminal, as they were in VS Code 1.109.x.

Actual Behavior

• Numpad keys work in the terminal shell before launching the TUI app
• Numpad keys are completely ignored once the TUI app is running
• Main keyboard number row works correctly inside the TUI
• The same TUI application works correctly with numpad in an external terminal (outside VS Code)

Analysis

This appears to be related to the Chromium 142 / Electron 39 regression where numpad keys report key: "Unidentified" (see #283460, chromium issue 405793116).

The normal terminal shell compensates using keyCode fallback, but when a TUI application activates enhanced keyboard mode (Kitty keyboard protocol / CSI u), xterm.js passes through the broken key identity from Chromium. The TUI receives "Unidentified" for numpad keys and drops them.

This is distinct from #283460 which covers numpad Delete in the editor. This issue specifically affects terminal TUI applications that use enhanced keyboard protocols.

Related Issues

• Numpad Delete key not working in version 1.107.0 (regression from 1.106.3) #283460 - Numpad Delete key not working (Chromium 142 regression, editor-level)
• Chromium issue 405793116
• Chromium issue 429730008