Fix NPE: use a getter for the current UserState

[nan-li]

Description

One Line Summary

Use a getter for the currentUserState to avoid a null pointer exception.

Details

Motivation

A customer reported 3 separate crashes for the app's users when (1) a device is logging out of email, or, (2) has logged out of email and is logging into a different email. The currentUserState is apparently null. To address these crash reports, replace currentUserState with getCurrentUserState() to avoid these NPE's.

I also replaced more instances of currentUserState with getCurrentUserState() than the 3 cases below reported by the user. These are other places in UserStateSynchronizer that access currentUserState and it could possibly be null.

Crash 1: Not reproducible

The obfuscated method seems to be this line.

Fatal Exception: java.lang.NullPointerException: 
Attempt to invoke virtual method 'i.g.u i.g.k4.e()' on a null object reference // probably currentUserState.getDependValues();
      at com.onesignal.UserStateSynchronizer.doEmailLogout(UserStateSynchronizer.java:261)
      at com.onesignal.UserStateSynchronizer.internalSyncUserState(UserStateSynchronizer.java:227)
      at com.onesignal.UserStateSynchronizer.syncUserState(UserStateSynchronizer.java:219)
      at com.onesignal.UserStateSynchronizer$NetworkHandlerThread$1.run(UserStateSynchronizer.java:110)
      at android.os.Handler.handleCallback(Handler.java:938)
      at android.os.Handler.dispatchMessage(Handler.java:99)
      at android.os.Looper.loopOnce(Looper.java:226)
      at android.os.Looper.loop(Looper.java:313)
      at android.os.HandlerThread.run(HandlerThread.java:67)

Crash 2: Not reproducible

Attempt to invoke virtual method 'org.json.JSONObject com.onesignal.UserState.generateJsonDiff(com.onesignal.UserState, boolean)' on a null object reference

Crash 3: Reproducible by the reporter, not reproducible on my end

java.lang.NullPointerException: Attempt to invoke virtual method
'void com.onesignal.UserState.setSyncValues(org.json.JSONObject)' on a null object reference
        at com.onesignal.UserStateSynchronizer.resetCurrentState(UserStateSynchronizer.java:573)
        at com.onesignal.UserStateSecondaryChannelSynchronizer.setChannelId(UserStateSecondaryChannelSynchronizer.java:156)
        at com.onesignal.OneSignalStateSynchronizer.setEmail(OneSignalStateSynchronizer.java:195)
        at com.onesignal.OneSignal.setEmail(OneSignal.java:1699)
        at com.onesignal.OneSignal.setEmail(OneSignal.java:1640)

Scope

In the places we were accessing currentUserState, it should not be null anyway. Using a getter just ensures this, and creates it if it is null.

Testing

Unit testing

No new unit testing done.

Manual testing

Because I couldn't reproduce any of these exceptions, it was not testable.

Affected code checklist

• Notifications
  • Display
  • Open
  • Push Processing
  • Confirm Deliveries
• Outcomes
• Sessions
• In-App Messaging
• REST API requests
• Public API changes
• Device State

Checklist

Overview

• I have filled out all REQUIRED sections above
• PR does one thing
• Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• I have included test coverage for these changes, or explained why they are not needed
• All automated tests pass, or I explained why that is not possible
• I have personally tested this on my device, or explained why that is not possible

Final pass

• Code is as readable as possible.
• I have reviewed this PR myself, ensuring it meets each checklist item

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This change is 

[jkasten2]

Thinking we should change all currentUserState usages to getCurrentUserState() for consistency.

Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @nan-li)

[nan-li]

Ok! Added another commit for this so that the first commit is to address the NPE specifically, and the second commit, for consistency.

Reviewable status: 0 of 1 files reviewed, all discussions resolved (waiting on @jkasten2)

[jkasten2]

Reviewed 1 of 1 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @nan-li)