[BUG] DiffViewProvider.open can throw "Tab close: Invalid tab not found!" and abort edits

[0xMink]

Problem

DiffViewProvider.open() in src/integrations/editor/DiffViewProvider.ts closes existing editor tabs for the file being edited before opening the diff view. The await vscode.window.tabGroups.close(tab) call at ~line 101 is unguarded — if the tab reference becomes invalid between lookup and close, it throws "Tab close: Invalid tab not found!" and aborts the entire edit operation.

This is best-effort cleanup (the file is already saved before this point). A failure to close an existing tab should not block the edit flow.

Context

• The same file already handles this correctly in closeAllDiffViews(), which swallows close failures gracefully.
• VS Code has an upstream regression producing the same error string: Tab list gets corrupted when a new webview is opened (extension API) microsoft/vscode#228270. The trigger there involves webview panel replacement, not identical to this code path, but the defensive posture is the same.
• Reported in [BUG] Roo code won't edit any files - Error apply patch #11358 (closed). The reporter was using VS Code on Windows connected to WSL, where the race window between tab lookup and close is wider due to remote latency.

Reproduction

Intermittent. More likely in remote/WSL environments. Triggered when a tab reference becomes stale between the filter at line 89 and the close at line 101 of DiffViewProvider.open().

Expected behavior

Tab close failure should be logged and swallowed. The diff view should open and editing should proceed normally.

Suggested fix

Wrap only the tabGroups.close(tab) call in open() with a try-catch, matching the existing pattern in closeAllDiffViews(). The this.documentWasOpen = true assignment must remain unconditional and outside the close success path.

[roomote]

I've analyzed this issue and here's my proposed implementation plan:

1. Wrap the tabGroups.close(tab) call in DiffViewProvider.open() (line 101 in src/integrations/editor/DiffViewProvider.ts) with a try-catch that logs the error and continues. This matches the defensive pattern already used in closeAllDiffViews() (lines 436-441), which swallows close failures with console.error.

2. Keep this.documentWasOpen = true unconditional -- it already sits outside the !tab.isDirty guard and must remain so, since we know a tab existed regardless of whether closing it succeeded.

The change is minimal -- roughly:

for (const tab of tabs) {
    if (!tab.isDirty) {
        try {
            await vscode.window.tabGroups.close(tab)
        } catch (err) {
            console.error(`Failed to close tab for ${absolutePath}`, err)
        }
    }
    this.documentWasOpen = true
}

3. Add a test to the existing DiffViewProvider.spec.ts confirming that when tabGroups.close rejects, open() still completes successfully and documentWasOpen is set to true.

This approach ensures tab close failures are logged but never block the edit flow, matching both the existing codebase convention and the expected behavior described in the issue.

Please mention @roomote in a comment saying that you approve this plan, and I'll proceed with the implementation.

[0xMink]

Related issues and PRs

Searched the repo for related work in the same code path:

Same code path (coordination needed):

• PR fix: preserve pinned tab state when editing files #11327 (open) — preserves pinned tab state in DiffViewProvider.open(), modifies the same for (const tab of tabs) loop. If both merge, they need reconciliation: the try-catch from this fix should wrap the close, while pin-state capture from fix: preserve pinned tab state when editing files #11327 should happen before it.

Established precedent:

• PR Resolve diff editor race condition in multi-monitor setups #4578 (merged) — introduced the defensive close pattern in closeAllDiffViews() that this fix mirrors.
• PR Fix: Preserve editor state and prevent tab unpinning during diffs #2857 (merged) — earlier tab state preservation in the same open() → saveChanges() → revertChanges() flow.
• PR fix(editor): prevent file editing issues when git diff views are open #8676 (merged) — added URI scheme checks in the same tab filter logic.

Original report:

• Issue [BUG] Roo code won't edit any files - Error apply patch #11358 (closed) — user report of "Error apply patch: Tab close: Invalid tab not found!" on Windows + WSL. Closed as non-repro, but the unguarded close is a real race condition.

Not in scope:

• src/integrations/misc/open-file.ts has a similar tabGroups.close() call but is already wrapped in a broader try {} catch {} block on current main.