Fix iOS build: form owned-userdata release callback from a closure literal

[azooz2003-bit]

Main's iOS build is red since f41507e (an untested "cmux reload-cloud"-authored commit): it passes the static method GhosttySurfaceBridge.releaseRetainedOpaque directly as a C function pointer to ghostty_surface_new_with_owned_userdata, which Swift only permits for global funcs or capture-free closure literals. Every CmuxMobileTerminal compile fails, which killed internal TestFlight run 30139324698 (and blocks all iOS uploads). This wraps the callback in a capture-free closure literal forwarding to the same method; no behavior change. Verified against the language rule and gated on a local GhosttyKit rebuild before merge.

🤖 Generated with Claude Code

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Summary by cubic

Fixes the iOS build by forming the owned-userdata release callback as a capture‑free closure literal when calling ghostty_surface_new_with_owned_userdata instead of passing the static method reference. This follows Swift’s C function pointer rules and restores CmuxMobileTerminal iOS builds and TestFlight uploads with no behavior change.

^{Written for commit a47e2fc. Summary will update on new commits.}

Summary by CodeRabbit

• Bug Fixes
  • Improved surface cleanup callback handling to ensure resources are released reliably when a terminal surface is closed.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: f369e15d-308f-4074-a4da-98e368afe885

📥 Commits

Reviewing files that changed from the base of the PR and between 46cc01f and a47e2fc.

📒 Files selected for processing (1)

• Packages/iOS/CmuxMobileTerminal/Sources/CmuxMobileTerminal/GhosttySurfaceView.swift

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📝 Walkthrough

Walkthrough

GhosttySurfaceView now supplies the userdata-release callback to ghostty_surface_new_with_owned_userdata as a capture-free closure calling GhosttySurfaceBridge.releaseRetainedOpaque.

Changes

Surface callback

Layer / File(s)	Summary
Capture-free userdata release callback Packages/iOS/CmuxMobileTerminal/Sources/CmuxMobileTerminal/GhosttySurfaceView.swift	The surface creation call uses a capture-free closure for releasing retained opaque userdata.
Estimated code review effort: 1 (Trivial)	~2 minutes

Suggested reviewers: lawrencecchen

🚥 Pre-merge checks | ✅ 25

✅ Passed checks (25 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly matches the main change: fixing the iOS build by using a closure literal for the owned-userdata release callback.
Description check	✅ Passed	The description includes a solid summary and testing notes; the remaining template sections are mostly non-critical for this code fix.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Cmux Swift Actor Isolation	✅ Passed	Diff only replaces a static method reference with a capture-free C callback closure; it adds no new MainActor, Sendable, or UI-store isolation issue.
Cmux Swift Blocking Runtime	✅ Passed	Diff only wraps a C callback in a capture-free closure; no waits, sleeps, syncs, polling, or locks were added.
Cmux Browser Automation Off-Main	✅ Passed	PR only changes GhosttySurfaceView.swift C callback wiring; no browser socket automation, policy switch, or tests were touched.
Cmux Expensive Synchronous Load	✅ Passed	Diff only swaps a C callback to a capture-free closure in GhosttySurfaceView; it adds no agent-history/JSON/load work on main actor or interactive paths.
Cmux Cache Substitution Correctness	✅ Passed	Diff only wraps a C callback for userdata teardown; no fresh-authoritative read is replaced by a cached/stale value in persistence/history/undo/snapshot logic.
Cmux No Hacky Sleeps	✅ Passed	The only change is a Swift closure-literal callback wrapper; no sleeps, timers, polling, or wall-clock waits were added.
Cmux Algorithmic Complexity	✅ Passed	Only change in GhosttySurfaceView.swift:3476-3490 is a capture-free C callback wrapper; no collection scans, sorting, or hot-path algorithm changes.
Cmux Swift Concurrency	✅ Passed	Diff only wraps a third-party C userdata-release callback in a capture-free closure; no new DispatchQueue/Task/Combine or other legacy async pattern is introduced.
Cmux Swift @Concurrent	✅ Passed	The change only wraps a C callback in a capture-free closure; it adds no @concurrent/nonisolated async code or UI-heavy async call sites.
Cmux Swift Package Boundaries	✅ Passed	Only a capture-free C callback bridge in GhosttySurfaceView/GhosttySurfaceBridge; it’s app-target Ghostty glue, not reusable domain logic.
Cmux Swiftpm Lockfiles	✅ Passed	Diff only changes a Swift source file; no Package.swift, .gitignore, workflow, or Xcode dependency files were touched, so the lockfile rule doesn’t apply.
Cmux Swift Logging	✅ Passed	The diff only wraps the callback in a capture-free closure; it adds no print/debugPrint/dump/NSLog, and the existing file-scoped Logger predates the PR.
Cmux User-Facing Error Privacy	✅ Passed	Diff only changes the Ghostty callback wiring; no user-facing errors, alerts, output copy, or disallowed details were added or altered.
Cmux Full Internationalization	✅ Passed	The change only wraps a Ghostty C callback in a capture-free closure; it adds no user-facing Swift/web text or catalog/routing updates.
Cmux Swiftui State Layout	✅ Passed	Diff only wraps a C callback in GhosttySurfaceView (a UIKit bridge); no new SwiftUI state/layout patterns were introduced.
Cmux Architecture Rethink	✅ Passed	A small platform-bridge fix: the C callback is wrapped in a capture-free closure, with no new timing, ownership, or lifecycle state.
Cmux Swift Auxiliary Window Close Shortcuts	✅ Passed	Touched code is a UIView surface callback change, not a standalone NSWindow/WindowGroup; no cmux identifier or close-shortcut ownership was added or altered.
Cmux Source Artifacts	✅ Passed	Only changed path is an intentional Swift source file; diff tweaks a callback and adds no artifacts, temp files, caches, or generated outputs.
Cmux No Test Or Debug Seam In Production Source	✅ Passed	The diff only wraps a C callback in a capture-free closure; it adds no #if DEBUG, test hook, or visibility-widening seam in production Sources.
Cmux No Ambient Global State	✅ Passed	Diff only wraps an existing callback in a capture-free closure inside makeSurface; it adds no new top-level globals, statics, or singleton state.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-ios-release-cfnptr

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[greptile-apps]

Greptile Summary

Fixes a Swift compiler error on iOS introduced by a prior commit that passed a static method reference directly as a C function pointer argument to ghostty_surface_new_with_owned_userdata. Swift only permits C function pointers to be formed from global functions or capture-free closure literals, not static method references.

• The fix wraps GhosttySurfaceBridge.releaseRetainedOpaque in a capture-free closure literal that forwards the single userdata argument unchanged — identical runtime behavior with no semantic change.
• releaseRetainedOpaque carries no actor isolation annotation and only calls Unmanaged.release(), so invoking it from a C callback context is safe.

Confidence Score: 5/5

Safe to merge — the change is a one-line mechanical fix that unblocks iOS compilation with no behavioral difference.

The closure is genuinely capture-free, forwards the argument identically, and releaseRetainedOpaque has no actor isolation, so the C-callback invocation path is sound. No rules are violated and no logic is altered.

Files Needing Attention: No files require special attention.

Important Files Changed

Filename	Overview
Packages/iOS/CmuxMobileTerminal/Sources/CmuxMobileTerminal/GhosttySurfaceView.swift	Wraps the static method reference in a capture-free closure literal to satisfy Swift's C function pointer constraint; fix is minimal, correct, and behavior-preserving.

Sequence Diagram

sequenceDiagram
    participant Swift as GhosttySurfaceView (Swift)
    participant C as ghostty_surface_new_with_owned_userdata (C)
    participant Closure as Capture-free closure
    participant Bridge as GhosttySurfaceBridge.releaseRetainedOpaque

    Swift->>Swift: Unmanaged.passRetained(bridge) → bridgePointer
    Swift->>C: "ghostty_surface_new_with_owned_userdata(app, &config, closure)"
    Note over Swift,C: Closure is capture-free — valid C function pointer
    C-->>Swift: ghostty_surface_t (or nil)

    Note over C,Closure: Later, when surface is freed
    C->>Closure: invoke(userdata)
    Closure->>Bridge: releaseRetainedOpaque(userdata)
    Bridge->>Bridge: Unmanaged.fromOpaque(userdata).release()

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