cmux/docs/ghostty-fork.md

Ghostty Fork Changes (manaflow-ai/ghostty)

This repo uses a fork of Ghostty for local patches that aren't upstream yet. When we change the fork, update this document and the parent submodule SHA.

Fork update checklist

1. Make changes in ghostty/.
2. Commit and push to manaflow-ai/ghostty.
3. Update this file with the new change summary + conflict notes.
4. In the parent repo: git add ghostty and commit the submodule SHA.

Current fork changes

Fork rebased onto upstream v1.3.0 plus newer main commits as of March 9, 2026.

1) OSC 99 (kitty) notification parser

• Commit: a2252e7a9 (Add OSC 99 notification parser)
• Files:
  • src/terminal/osc.zig
  • src/terminal/osc/parsers.zig
  • src/terminal/osc/parsers/kitty_notification.zig
• Summary:
  • Adds a parser for kitty OSC 99 notifications and wires it into the OSC dispatcher.

2) macOS display link restart on display changes

• Commit: c07e6c5a5 (macos: restart display link after display ID change)
• Files:
  • src/renderer/generic.zig
• Summary:
  • Restarts the CVDisplayLink when setMacOSDisplayID updates the current CGDisplay.
  • Prevents a rare state where vsync is "running" but no callbacks arrive, which can look like a frozen surface until focus/occlusion changes.

3) Keyboard copy mode selection C API

• Commit: a50579bd5 (Add C API for keyboard copy mode selection)
• Files:
  • src/Surface.zig
  • src/apprt/embedded.zig
• Summary:
  • Restores ghostty_surface_select_cursor_cell and ghostty_surface_clear_selection.
  • Keeps cmux keyboard copy mode working against the refreshed Ghostty base.

4) macOS resize stale-frame mitigation

Sections 3 and 4 are grouped by feature, not by commit order. The fork branch HEAD is the section 3 copy-mode commit, even though the section 4 resize commits were applied earlier.

• Commits:
  • 769bbf7a9 (macos: reduce transient blank/scaled frames during resize)
  • 9efcdfdf8 (macos: keep top-left gravity for stale-frame replay)
• Files:
  • pkg/macos/animation.zig
  • src/Surface.zig
  • src/apprt/embedded.zig
  • src/renderer/Metal.zig
  • src/renderer/generic.zig
  • src/renderer/metal/IOSurfaceLayer.zig
• Summary:
  • Replays the last rendered frame during resize and keeps its geometry anchored correctly.
  • Reduces transient blank or scaled frames while a macOS window is being resized.

Upstreamed fork changes

cursor-click-to-move respects OSC 133 click-to-move

• Was local in the fork as 10a585754.
• Landed upstream as bb646926f, so it is no longer carried as a fork-only patch.

Merge conflict notes

These files change frequently upstream; be careful when rebasing the fork:

• src/terminal/osc/parsers.zig

  • Upstream uses std.testing.refAllDecls(@This()) in test {}.
  • Ensure iterm2 import stays, and keep kitty_notification import added by us.

• src/terminal/osc.zig

  • OSC dispatch logic moves often. Re-check the integration points for the OSC 99 parser.

If you resolve a conflict, update this doc with what changed.