Hold Files tree reloads while its context menu is open

[teamleaderleo]

Summary

Ctrl-clicking a row in the Files sidebar could crash cmux (#12914, 4 reports on 0.64.24 and 0.64.25). Every report has the same stack: AppKit throws from -[NSTableRowData rowViewAtRow:createIfNeeded:] while drawing the context-menu highlight for the clicked row, inside the Core Animation commit that NSContextMenuTrackingSession startMonitoringEvents runs as the menu appears.

AppKit keeps the clicked row index for that highlight until the menu closes. Meanwhile the Files coordinator reloads the outline (reloadData, and reloadItem(_:reloadChildren:) plus re-expansion for every loaded folder) whenever the store changes, and SwiftUI's updateNSView calls the same reloadIfNeeded() synchronously. SwiftUI flushes those updates inside a Core Animation commit, so a reload can land between the highlight row being chosen and being drawn. Store changes are frequent here: hovering a folder prefetches its children, and git status and directory watchers publish too.

The outline now tracks its own context menu with willOpenMenu(_:with:) / didCloseMenu(_:with:). While the menu is open, reloadIfNeeded() records that it owes a reload and returns without touching rows. When the menu closes it runs one catch-up reload on the next main-queue turn, after AppKit has cleared the highlight. Menu actions keep working because each item already carries its FileExplorerNode as representedObject.

The Find results table has the same shape (a context menu over rows that stream in) but is not in the reports; I left it alone here.

Fixes #12914

Testing

• New FileExplorerContextMenuReloadTests: with three rows loaded, it opens the menu, shrinks the store to one row and reloads (rows stay at 3), then closes the menu and waits up to 2 s for the deferred reload (rows become 1). It runs in the cmux unit lane in CI; I did not build cmux locally.
• I could not reproduce the crash locally, so the exact trigger (which store change lands inside the popup commit) is inferred from the stack and the code, not observed. The change only delays outline reloads while a Files context menu is on screen.
• scripts/lint-pbxproj-test-wiring.sh and scripts/check-pbxproj.sh pass.

Checklist

• Behavior changes have added or updated tests, or Testing says why not

🤖 Generated with Claude Code

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Summary by cubic

Fixes the cmux crash on ctrl-clicking a Files sidebar row by holding outline reloads while a context menu is open.

AppKit keeps drawing the context-menu highlight for the clicked row until the menu closes and throws if a reload removes that row underneath it. The outline now tracks its own context menu and skips reloads while one is on screen; a single catch-up reload runs on the next main-queue turn after the menu closes. Menu actions are unaffected since each item already carries its node as representedObject. The Find results table has the same shape but is not in the crash reports, so it is left unchanged.

Testing

• New FileExplorerContextMenuReloadTests covers the hold-then-catch-up behavior.
• The crash could not be reproduced locally, so the trigger is inferred from the stack trace and code rather than observed.

^{Written for commit acee8e6. Summary will update on new commits.}

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📥 Commits

Reviewing files that changed from the base of the PR and between 812288a and acee8e6.

📒 Files selected for processing (4)

• Sources/FileExplorerNSOutlineView.swift
• Sources/FileExplorerView.swift
• cmux.xcodeproj/project.pbxproj
• cmuxTests/FileExplorerContextMenuReloadTests.swift

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[github-actions]

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[teamleaderleo]

Merged per Leo's direction to land without waiting on full CI. Reviewed adversarially (AppKit ordering checked with a probe: menuNeedsUpdate, then willOpenMenu, then the popup; open/close always pair). Caveat: this head's macOS compile admission never started. It sat queued on blacksmith-6vcpu-macos-26 for about 2.5 hours over three attempts, so the first compile of this change is main's next build. If main goes red in FileExplorerView.swift, FileExplorerNSOutlineView.swift or FileExplorerContextMenuReloadTests.swift, that's this PR.

[github-actions]

Merge receipt for acee8e6b86, merged 2026-09-25 12:53:02 UTC

• Not verified at merge: ci-status (not reported), macOS compile admission (in progress)
• Verified: Web complexity, web-validation, Fast static checks, GhosttyKit release check, guards (17), linux-preflight, macOS admission gate, Testbox broker trust boundary
• Skipped by policy: browser, Claude wrapper regressions, remote-daemon, suite-coverage, swift-package-tests, web, web-build, web-database-tests, web-tests
• Full suite: runs on main after merge.

Labeled merged-unverified: if main breaks near this merge, look here first.