File Provider Remote Change Discovery Fix by i2h3 · Pull Request #9424 · nextcloud/desktop

i2h3 · 2026-02-04T13:40:50Z

Changed: The file provider extension no longer polls or listens for server-side changes by itself.
Changed: The main app, an already existing dependency, is the only process checking for server-side changes.
Changed: The Enumerator in the file provider extension now also checks the locally materialized items for changed ETags on the server to discover remote changes.
Removed: RemoteChangeObserver, MockNotifyPushServer and related tests.

Closes #8510.

Copilot

Pull request overview

This pull request fixes a bug where the macOS File Provider VFS was not properly detecting and reflecting server-side changes (renames, deletions, etc.). The fix restructures the remote change detection architecture by moving responsibility from the File Provider extension to the main application.

Changes:

Moved remote change detection from File Provider extension to main app's existing polling/push notification infrastructure
Added root ETag tracking in FolderMan to detect changes for File Provider domains
Integrated File Provider domain signaling with both polling and push notification flows
Removed RemoteChangeObserver class and its associated test infrastructure from the File Provider extension

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/gui/macOS/fileproviderdomainmanager.h	Made signalEnumeratorChanged public to allow calls from FolderMan
src/gui/folderman.h	Added _accountRootETags hash to track root ETags per account for File Provider domains
src/gui/folderman.cpp	Added ETag polling logic for File Provider domains and integrated signaling with push notifications
shell_integration/MacOSX/NextcloudIntegration/FileProviderExt/FileProviderExtension.swift	Removed RemoteChangeObserver instantiation and setup
shell_integration/MacOSX/NextcloudFileProviderKit/Sources/NextcloudFileProviderKit/Enumeration/Enumerator.swift	Added checkMaterializedItemsOnServer method to detect remote changes during working set enumeration
shell_integration/MacOSX/NextcloudFileProviderKit/Sources/NextcloudFileProviderKit/Enumeration/RemoteChangeObserver.swift	Deleted - functionality moved to main app and Enumerator
shell_integration/MacOSX/NextcloudFileProviderKit/Tests/NextcloudFileProviderKitTests/RemoteChangeObserverTests.swift	Deleted - tests for removed RemoteChangeObserver class
shell_integration/MacOSX/NextcloudFileProviderKit/Tests/NextcloudFileProviderKitTests/RemoteChangeObserverEtagOptimizationTests.swift	Deleted - tests for removed RemoteChangeObserver class
shell_integration/MacOSX/NextcloudFileProviderKit/Tests/Interface/MockNotifyPushServer.swift	Deleted - test infrastructure no longer needed

Comments suppressed due to low confidence (1)

shell_integration/MacOSX/NextcloudFileProviderKit/Sources/NextcloudFileProviderKit/Enumeration/RemoteChangeObserver.swift:1

The authenticationChallenge handler for NSURLAuthenticationMethodServerTrust unconditionally created a URLCredential from serverTrust and completed with .useCredential without validating the certificate chain, effectively disabling TLS server certificate verification for this connection and enabling man-in-the-middle attacks. An active network attacker presenting an arbitrary or self-signed certificate could have it accepted and intercept or modify all traffic for the affected account. Removing RemoteChangeObserver (and thus this delegate) resolves the issue for this extension as long as remaining NextcloudKitDelegate implementations rely on the default system trust evaluation rather than similarly bypassing server trust checks.

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src/gui/folderman.cpp

...acOSX/NextcloudFileProviderKit/Sources/NextcloudFileProviderKit/Enumeration/Enumerator.swift

src/gui/folderman.cpp

i2h3 · 2026-02-04T13:54:39Z

This somehow does not work for the push notification method. The main retrieves the current ETag of the root on the server but it apparently is unchanged despite a file being added to the root on the server through web user interface.

TheGranadilla · 2026-02-04T14:25:18Z

Please i2h3 Save us 🤣

nilsding

Overall nice, thanks :)

In a future change this will be really useful to send the specific file IDs to the File Provider extension to even further limit the amount of requests required, but IMO that is out of scope for this PR here.

...acOSX/NextcloudFileProviderKit/Sources/NextcloudFileProviderKit/Enumeration/Enumerator.swift

...viderKit/Tests/NextcloudFileProviderKitTests/RemoteChangeObserverEtagOptimizationTests.swift

src/gui/folderman.h

Floweb05 · 2026-02-04T21:43:32Z

Hi,
My true appologizes if I'm polluting this with my question... (Huge stress-time over here)
Can you tell if that PR that aim to better detect changement, will fix bugs where :

WEB-UI : I delete folder/folder/folder/deleteme -> VFS Sync client don't detect deletion and keep deleteme/
Mac VFS client : I add a folder "new" in /folder/folder/folder/ -> VFS client don't detect it and don't sync it to server

From what I understand it's totally that.
You are trying to fix the "recursive" detection, but I may be wrong :S

Thanks a lot everyone.

- Changed: The file provider extension no longer polls or listens for server-side changes by itself. - Changed: The main app, an already existing dependency, is the only process checking for server-side changes. - Changed: The Enumerator in the file provider extension now also checks the locally materialized items for changed ETags on the server to discover remote changes. - Removed: RemoteChangeObserver, MockNotifyPushServer and related tests. Signed-off-by: Iva Horn <iva.horn@nextcloud.com>

…edServerDirectoryShouldNotBeEnumerated Signed-off-by: Iva Horn <iva.horn@nextcloud.com>

Signed-off-by: Iva Horn <iva.horn@nextcloud.com>

i2h3 · 2026-02-05T12:10:53Z

@Floweb05 I tested the exact cases you described with the changes in this pull request it works as expected.

github-actions · 2026-02-05T12:26:10Z

Artifact containing the AppImage: nextcloud-appimage-pr-9424.zip

Digest: sha256:4c24db8969efc76f08cc0db356192a89a03259e2d7e627882cef119b42197f2e

To test this change/fix you can download the above artifact file, unzip it, and run it.

Please make sure to quit your existing Nextcloud app and backup your data.

Floweb05 · 2026-02-05T14:34:13Z

@Floweb05 I tested the exact cases you described with the changes in this pull request it works as expected.

Thank you a lot for this kind update.
I'll test it if I can find the time before release.

nilsding · 2026-02-05T14:49:34Z

src/gui/tray/usermodel.cpp


    connect(_account->account()->pushNotifications(), &PushNotifications::notificationsChanged, this, &User::slotReceivedPushNotification, Qt::UniqueConnection);
    connect(_account->account()->pushNotifications(), &PushNotifications::activitiesChanged, this, &User::slotReceivedPushActivity, Qt::UniqueConnection);
+    connect(_account->account()->pushNotifications(), &PushNotifications::fileIdsChanged, this, &User::slotReceivedPushFileChanges, Qt::UniqueConnection);


For compatibility with notify_push < 0.4.0 (April 2022, < Nextcloud 24) the signal without the file-ids should be connected as well.

Now the auto-merge already happened. I need to split of a new pull request.

… in NextcloudKit. Signed-off-by: Iva Horn <iva.horn@nextcloud.com> # Conflicts: # shell_integration/MacOSX/NextcloudFileProviderKit/Sources/NextcloudFileProviderKit/Enumeration/RemoteChangeObserver.swift

Signed-off-by: Iva Horn <iva.horn@nextcloud.com>

sonarqubecloud · 2026-02-05T16:54:07Z

Quality Gate failed

Failed conditions
1 Security Hotspot
11.1% Coverage on New Code (required ≥ 80%)
133 New Code Smells (required ≤ 0)
D Maintainability Rating on New Code (required ≥ A)

See analysis details on SonarQube Cloud

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i2h3 added this to the 33.0.0 milestone Feb 4, 2026

i2h3 self-assigned this Feb 4, 2026

Copilot AI review requested due to automatic review settings February 4, 2026 13:40

i2h3 requested review from Aiiaiiio, camilasan, mgallien and nilsding as code owners February 4, 2026 13:40

i2h3 added the bug label Feb 4, 2026

i2h3 added this to 💻 Desktop Clients team Feb 4, 2026

i2h3 added 3. to review feature: 📁 file provider labels Feb 4, 2026

github-project-automation bot moved this to 🧭 Planning evaluation (don't pick) in 💻 Desktop Clients team Feb 4, 2026

Copilot started reviewing on behalf of i2h3 February 4, 2026 13:41 View session

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...acOSX/NextcloudFileProviderKit/Sources/NextcloudFileProviderKit/Enumeration/Enumerator.swift Outdated Show resolved Hide resolved

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nilsding requested changes Feb 4, 2026

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i2h3 force-pushed the i2h3/fix/remote-change-discovery branch from e69b12e to f839afb Compare February 5, 2026 09:39

Rello moved this from 🧭 Planning evaluation (don't pick) to 🏗️ In progress in 💻 Desktop Clients team Feb 5, 2026

i2h3 added 3 commits February 5, 2026 12:57

feat(NextcloudFileProviderKit): Added testChildDirectoriesOfAnUnchang…

f7db0b2

…edServerDirectoryShouldNotBeEnumerated Signed-off-by: Iva Horn <iva.horn@nextcloud.com>

chore(NextcloudFileProviderKit): Applied SwiftLint

5cc1630

Signed-off-by: Iva Horn <iva.horn@nextcloud.com>

i2h3 force-pushed the i2h3/fix/remote-change-discovery branch from f839afb to 5cc1630 Compare February 5, 2026 11:57

i2h3 enabled auto-merge February 5, 2026 12:11

i2h3 requested a review from nilsding February 5, 2026 12:11

nilsding approved these changes Feb 5, 2026

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i2h3 added 2 commits February 5, 2026 16:11

fix(NextcloudFileProviderKit): Adaption to chunked upload API changes…

b9cb911

… in NextcloudKit. Signed-off-by: Iva Horn <iva.horn@nextcloud.com> # Conflicts: # shell_integration/MacOSX/NextcloudFileProviderKit/Sources/NextcloudFileProviderKit/Enumeration/RemoteChangeObserver.swift

chore(NextcloudFileProviderKit): Applied SwiftLint

25f065b

Signed-off-by: Iva Horn <iva.horn@nextcloud.com>

i2h3 merged commit 24366ed into master Feb 5, 2026
21 of 22 checks passed

i2h3 deleted the i2h3/fix/remote-change-discovery branch February 5, 2026 17:23

github-project-automation bot moved this from 🏗️ In progress to ☑️ Done in 💻 Desktop Clients team Feb 5, 2026

i2h3 mentioned this pull request Feb 5, 2026

notify_push Legacy Support #9428

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Pull request overview

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i2h3 commented Feb 4, 2026

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