RealmChangeListener not triggered, after object was deleted and replaced with same primary key.

[dan-ahlquist]

Goal

Receive updates through a RealmChangeListener, when a managed object is deleted, then replaced in one transaction. The new object has the same key, but other fields are updated.

Actual Results

• For a RealmObject type with no Primary Key, the listener was triggered. (Pass)
• For a RealmObject type with an int Primary Key, the listener was triggered. (Pass)
• For a RealmObject type with a String Primary Key, the listener was not triggered. (Fail)

Steps & Code to Reproduce

See attached Android Studio project, which demonstrates the behavior.

1. Pre-condition: two records in Realm (one with no PK, one with a String PK).
2. Register a RealmChangeListener for each type.
3. Replace each object (in separate transactions) - this is done on an RxAndroid chain.
   a. This is done by using deleteAllFromRealm, then inserting the new object
   with copyToRealm.
   b. The key of the new object is the same as the deleted one, but other
   fields are updated.

Version of Realm and tooling

Realm version(s): 7.0.0 and up.
I bisected through Realm versions. 6.1.0 was "good" and 7.0.0 was "bad"

Realm Sync feature enabled: No

Android Studio version: 4.0

Android Build Tools version: 30.0.1, and 29.0.3. Same results.

Gradle version: 3.4.0 and 4.0.0. Same results.

Which Android version and device(s): Android 9 and 10, various devices. Originally reported on S10+ with Android 9.

ChangeListenerBug.zip

[clementetb]

Thanks for reporting the issue and sharing the project to reproduce it. We have reported it to the realm core team who will look for a fix.

#4010