onCancel not called on permission error

[yh1224]

Environment

• Android Studio version: 3.2 RC3
• Firebase Component: Database
• Component version: 16.0.2 / 11.8.0

Problem

addListener to the reference which has no permissions, then
onCancel will be called with DatabaseError: Permission denied.

But adding more than two listeners to the same reference with and without orderBy,
onCancel called for only listeners with orderBy, not for listeners without orderBy.

Steps to reproduce:

val ref = FirebaseDatabase.getInstance().getReference("test")
ref.orderByKey().addListenerForSingleValueEvent(...)  -> called
ref.addListenerForSingleValueEvent(...)  -> not called
ref.orderByKey().addValueEventListener(...)  -> called
ref.addValueEventListener(...)  -> not called
ref.orderByKey().addChildEventListener(...)  -> called
ref.addChildEventListener(...)  -> not called

Add listeners by different order, then onCancel called for all listeners.

val ref = FirebaseDatabase.getInstance().getReference("test")
ref.addListenerForSingleValueEvent(...)  -> called
ref.orderByKey().addListenerForSingleValueEvent(...)  -> called
ref.addValueEventListener(...)  -> called
ref.orderByKey().addValueEventListener(...)  -> called
ref.addChildEventListener(...)  -> called
ref.orderByKey().addChildEventListener(...)  -> called

[schmidt-sebastian]

Hi @yh1224, thanks for letting us know about this. We currently have a backlog of issues to work through, and will prioritize this accordingly. I suspect that this has something to do with our persistence cache, and all but one listener return results from cache. Please don't quote me on this until we verify this assumption though!

Thank you.

[mikelehen]

FWIW I think the issue may be related to the fact that when we listen to a query, we'll treat a query that loads all data (even if it has an orderBy) as a "default" query (no query constraints, etc.):

firebase-android-sdk/firebase-database/src/main/java/com/google/firebase/database/core/SyncTree.java

Line 779 in 8982700

if (query.loadsAllData() && !query.isDefault()) {

I believe this means that the orderBy() and non-orderBy() queries will be de-duped into a single backend listen request.

But when we get a listen error and cancel the event registrations, we seem to treat orderBy and non-orderBy queries as distinct. This comment makes that sound intentional, but I don't understand why. It seems like it should match the other code. :-/

firebase-android-sdk/firebase-database/src/main/java/com/google/firebase/database/core/SyncTree.java

Line 591 in 8982700

// A removal on a default query affects all queries at that location. A removal on an

So I think the fix is somewhere in that code, but given the complexity and age of this code it may be a semi-risky thing to mess with.

[schmidt-sebastian]

Closing this due to inactivity. Please re-open if this is still an issue.