Firestore crash on invalid permissions

[nitrag]

• Xcode version: 9.1
• Firebase SDK version: 4.7
• Firebase Component: Firestore
• Component version: 0.9.3

Calling .setData() on a Document with invalid permissions (on the backend database rules) results in a hard crash.

    func updateUser(){
        var refresh: [String : Any] = [
            "first_name": self.api_user.user.first_name,
            "last_name": self.api_user.user.last_name,
            "username": self.api_user.user.username,
            "last_active": Date()
        ]
        self.db.collection("users").document(self.firebase_user.uid).setData(refresh, options: SetOptions.merge()) { err in
            if let err = err {
                print("error: \(err)")
            }else{
                print("SUCCESS FirestoreClient.updateUser")
            }
        }
    }

Crash:

    ERROR FirestoreClient.updateUser: Missing or insufficient permissions.
    2017-12-05 18:42:08.963700-0500 MeetYouThere[77409:2346136] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'FIRESTORE INTERNAL ASSERTION FAILED: Delegate must be nil'
    *** First throw call stack:
    (
        0   CoreFoundation                      0x0000000103ee21ab __exceptionPreprocess + 171
        1   libobjc.A.dylib                     0x0000000103577f41 objc_exception_throw + 48
        2   CoreFoundation                      0x0000000103ee7372 +[NSException raise:format:arguments:] + 98
        3   Foundation                          0x000000010301c089 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 193
        4   MeetYouThere                        0x0000000100bd0807 -[FSTStream startWithDelegate:] + 722
        5   MeetYouThere                        0x0000000100bd2e4f -[FSTWriteStream startWithDelegate:] + 82
        6   MeetYouThere                        0x0000000100bc6661 -[FSTRemoteStore startWriteStream] + 84
        7   MeetYouThere                        0x0000000100bc70a5 -[FSTRemoteStore writeStreamWasInterruptedWithError:] + 244
        8   MeetYouThere                        0x0000000100bd2eef -[FSTWriteStream notifyStreamInterruptedWithError:] + 79
        9   MeetYouThere                        0x0000000100bd14b1 -[FSTStream closeWithFinalState:error:] + 657
        10  MeetYouThere                        0x0000000100bd1d46 -[FSTStream handleStreamClose:] + 144
        11  MeetYouThere                        0x0000000100bd22a6 __37-[FSTStream writesFinishedWithError:]_block_invoke + 69
        12  libdispatch.dylib                   0x0000000107b363f7 _dispatch_call_block_and_release + 12
        13  libdispatch.dylib                   0x0000000107b3743c _dispatch_client_callout + 8
        14  libdispatch.dylib                   0x0000000107b3f95b _dispatch_queue_serial_drain + 1162
        15  libdispatch.dylib                   0x0000000107b402df _dispatch_queue_invoke + 336
        16  libdispatch.dylib                   0x0000000107b3c07d _dispatch_queue_override_invoke + 733
        17  libdispatch.dylib                   0x0000000107b431f9 _dispatch_root_queue_drain + 772
        18  libdispatch.dylib                   0x0000000107b42e97 _dispatch_worker_thread3 + 132
        19  libsystem_pthread.dylib             0x0000000107ff65a2 _pthread_wqthread + 1299
        20  libsystem_pthread.dylib             0x0000000107ff607d start_wqthread + 13
    )
    libc++abi.dylib: terminating with uncaught exception of type NSException

Here are the incorrect Firestore Rules. I have since corrected the rules to be valid and the iOS app no longer crashes, however, that's not a long term solution.

  service cloud.firestore {
     match /databases/{database}/documents {
       match /users/{userId} {
         allow read, write: if get(/databases/$(database)/documents/users/$(request.auth.uid)).data.isAdmin == true;
         allow read, write: if auth != null && auth.uid == $userId;
         allow create: if request.auth != null;
       }
     }
   }

[ghost]

I've also experienced this issue frequently when calling setData() on a document with invalid permissions. As a workaround for now, I've had to make some very careful checks in my code before writing to Firestore - definitely not an ideal long solution.

[jaysquared]

I have the same problem. An update would work a couple of times, before the it crashes eventually. Even when changing the rules to wide open:

match /Rounds/{roundId} {
    allow read: if true;
    allow create: if false;
    allow update: if true;
    allow delete: if false;
}

[schmidt-sebastian]

Thanks for reporting this. This is likely already fixed with #510, which will be part of our next release. I will try to see if I can re-produce this issue with and without this PR.

[schmidt-sebastian]

The fix for this has been released as part of 4.8.0.