fix(file-provider): drop a row whose folder is gone from the server - #11025

Resolves

No issue filed. Found while testing on a live account.

Summary

A metadata row whose parent folder no longer exists on the server is never cleaned up.

On the test account, four .indd files had rows under …/2026_Kaarten/Ontwerp/, a folder that no longer existed at that path on the server. As it turned out, it had been moved to 02_DESIGN/oud, files included. Nothing removed or corrected those rows:

• the working-set scan does not reach them, because they are not materialised;
• no depth-1 read of the vanished folder can report them as deleted, because the folder is gone.

Every lookup of such an item goes through parentItemIdentifierWithRemoteFallback, reads the folder, gets 404, and fails again. In practice that means a burst of errors per item on each framework cache refresh after an update:

error Could not get item parent directory item metadata for metadata.  15081073…
error Read of URL did fail.  …/2026_Kaarten/Ontwerp  errorCode 404
error Could not retrieve parent item identifier remotely.  15081073…
error Not modifying item because it was not found.  15081073…

At the first such refresh macOS also answered requestModification with "the file does not exist". The system had never known these items; they only lived in the database.

The fix

When the parent read returns 404 and the item is not materialised (not a downloaded file, not a visited folder), the row is marked deleted. Nothing can exist below a folder the server no longer has.

• Materialised items are left alone. The working-set scan already handles them. Acting on them here could race a rename of their folder that the database has not seen yet, and drop a downloaded file.
• Any other failure leaves the row alone, for example a 503.
• If the item has in fact moved, its next read restores the row by its identifier.

The change is 8 lines in FilesDatabaseManager.parentItemIdentifierWithRemoteFallback.

Tests

New ParentRemoteFallbackTests:

• testARowWhoseFolderIsGoneFromTheServerIsMarkedDeleted: the regression test. It fails without the fix and passes with it.
• testADownloadedFileIsLeftToTheScan, testAVisitedFolderIsLeftToTheScan, testAnotherReadFailureLeavesTheRowAlone, testAFolderThatStillExistsResolvesWithoutTouchingTheRow: guards. They pass both before and after.

Full suite, run locally with swift test:

• 394 XCTest (6 skipped, 0 failures) and 195 swift-testing tests, on master 3527955c09.
• The first run hit two of the known timing-flaky EnumeratorTests cases, and swift-testing runs occasionally crash in swiftpm-testing-helper. Both also happen on unmodified master. The reruns were clean.
• swiftformat --lint . is clean.

The same commit also applies and passes on top of #11004 (GRDB), once the test's initializer call gets try.

Moved rather than deleted

In the case above the files had moved, not gone. Later, a system-initiated re-listing (fileproviderd stream reset) read 02_DESIGN/oud and corrected all four rows by their identifiers. With this change the rows would have been marked deleted in between, and then restored by that same read: rows are matched by identifier, and the server payload carries deleted = false. Because these items were neither downloaded nor known to the system, nothing visible changes in between.

Not verified

• That deleting these rows makes the burst disappear on the next update in the running app. The test covers the database behaviour, not the framework refresh. On the test account the rows had already been corrected by the re-listing before this build ran.

Checklist

• Sign-off message is added to all commits.
• The commit messages are following The Conventional Commits specification.
• The commit history is clean with no merge commits.
• Uploaded screenshots from before and after for UI changes.
• Test(s) added to branch, with before/after results included in PR description, for performance improvements where applicable.
• Documentation has been updated or is not required.
• Backports requested where applicable (critical bugfixes).
• Labels added where applicable (bug/enhancement).
• Milestone added for target version.

AI (if applicable)

• The content of this PR was partly or fully generated using AI
  • I have read the guidelines for AI-assisted contributions.
  • I have read Nextcloud's AI Contribution Policy.

The code, tests and this description were written by Claude Code (Claude Opus 5.5) at my request, from a diagnosis of my own account's logs and database.

🤖 Generated with Claude Code