• Firebase Component: Common
• Component version: 20.4.2

Steps to reproduce:

Crashlytics notified us about a crash in FirebaseApp.UserUnlockReceiver.unregister. The method is only called from FirebaseApp.UserUnlockReceiver.onReceive which in turn only responds to android.intent.action.USER_UNLOCKED. I don't know how many times the system sends the broadcast but it apparently isn't just once.

Relevant Code:

FirebaseApp initialization may be idempotent but Context.unregisterReceiver isn't. The method crashes if the receiver isn't registered.

Suggested solution

public void unregister() { try { applicationContext.unregisterReceiver(this); } catch (IllegalArgumentException ignore) { // The receiver isn't registered. } }