Fix portal mutation tracker launch crash

[azooz2003-bit]

No description provided.

[coderabbitai]

📝 Walkthrough

Walkthrough

The insertion tracker now prepares hierarchy state before AppKit receives the borrowed child reference. Both swizzled subview-addition methods use this pre-insertion hook and remove post-insertion recording.

Changes

Pre-Insertion Hierarchy Tracking

Layer / File(s)	Summary
Prepare hierarchy state before AppKit insertion Sources/PortalViewHierarchyMutationTracker.swift, Sources/PortalSplitDividerCacheInvalidator.swift	The insertion hook is renamed to prepareForInsertion. Both subview-addition hooks call it before the original AppKit mutation with the subview’s current window.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• manaflow-ai/cmux#8580: Introduces the insertion hooks and tracker updated by this change.

Suggested reviewers: ejc3

🚥 Pre-merge checks | ✅ 24 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	No pull request description was provided, so all required template sections are missing.	Add the Summary, Testing, Demo Video, Review Trigger, and Checklist sections with the required details.

✅ Passed checks (24 passed)

Check name	Status	Explanation
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	The diff changes insertion timing and naming only; it adds no isolation declarations, and the tracker and invalidator remain explicitly @MainActor-isolated.
Cmux Swift Blocking Runtime	✅ Passed	The production Swift diff only moves insertion tracking before AppKit calls and renames the helper; it adds no semaphores, waits, sleeps, delayed dispatch, polling, sync, or locks.
Cmux Browser Automation Off-Main	✅ Passed	The actual diff changes only portal hierarchy tracker files; it adds no browser.* command, socket-worker routing, WebKit wait, or policy-test change covered by this rule.
Cmux Expensive Synchronous Load	✅ Passed	The diff only reorders in-memory NSView hierarchy tracking and renames the insertion hook; changed files add no agent-history loader, file read, directory scan, JSON parse, or SharedLiveAgentIndex...
Cmux Cache Substitution Correctness	✅ Passed	The diff only moves AppKit insertion tracking before mutation; it replaces no fresh disk, database, or file read, and the tracker serves transient divider UI cache state, not persistence, history,...
Cmux No Hacky Sleeps	✅ Passed	The diff changes only two Swift source files and adds no sleep, timer, polling, or fixed-delay synchronization; this rule explicitly excludes Swift.
Cmux Algorithmic Complexity	✅ Passed	The diff only moves the existing constant-time insertion bookkeeping before AppKit and renames it; it adds no scalable scans, sorting, filtering, joins, or slower algorithm.
Cmux Swift Concurrency	✅ Passed	The diff only renames and moves a synchronous AppKit insertion tracker call; it adds no Dispatch, Task, Combine, or completion-handler async pattern.
Cmux Swift @Concurrent	✅ Passed	The diff changes only synchronous AppKit hooks and a synchronous @MainActor method rename; it adds no async/nonisolated work or @concurrent annotation.
Cmux Swift Package Boundaries	✅ Passed	The diff only adjusts private NSView/NSSplitView AppKit swizzle hooks and an @MainActor AppKit tracker; it adds no independent reusable domain logic, and AppKit glue is explicitly allowed.
Cmux Swiftpm Lockfiles	✅ Passed	The diff changes only two source files; it contains no Package.swift, Package.resolved, .gitignore, workflow, or Xcode package-reference changes that trigger this policy.
Cmux Swift Logging	✅ Passed	The exact Swift diff only moves insertion tracking and updates documentation; it adds or changes no print, Logger, file/stdout logging, or sensitive-data logging.
Cmux User-Facing Error Privacy	✅ Passed	The diff only changes internal Swift hierarchy hooks and developer documentation; it adds no user-facing error, alert, command output, or new string literal.
Cmux Full Internationalization	✅ Passed	The PR diff changes only Swift hook logic and developer-only comments; it adds no user-facing text and changes no catalogs, plist, web, or locale message files.
Cmux Swiftui State Layout	✅ Passed	The diff changes AppKit portal mutation hooks only; no SwiftUI state, measurement, lazy-row store reference, or render-time mutation is introduced.
Cmux Architecture Rethink	✅ Passed	The diff is a small AppKit bridge correctness fix: the MainActor tracker remains the owner, docs state the borrowed-reference invariant, and no timing, blocking, duplicate-path, or new-state mechan...
Cmux Swift Auxiliary Window Close Shortcuts	✅ Passed	The diff changes only NSView insertion hooks and hierarchy tracking; it adds or materially changes no NSWindow, NSPanel, WindowController, SwiftUI Window, or WindowGroup.
Cmux Source Artifacts	✅ Passed	The diff changes only two intentional Swift source files; it adds no logs, caches, build output, scratch directories, downloads, or other source-control artifacts.
Cmux No Test Or Debug Seam In Production Source	✅ Passed	The diff only renames the insertion tracker and moves its production call before AppKit mutation; it adds no DEBUG guard, test/debug-named member, or test-only accessor in Sources/.
Cmux No Ambient Global State	✅ Passed	The diff only renames an existing method on PortalViewHierarchyMutationTracker and changes hook ordering; it adds no top-level function, mutable global, static namespace, or singleton.
Title check	✅ Passed	The title clearly identifies the primary change: fixing a launch crash in the portal mutation tracker.

✨ 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-portal-associated-lifetime

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