PatientListViewModel Null Pointer Exception Line 77

[trevorgowing]

Describe the bug
PatientListViewModel Null Pointer Exception Line 77

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.google.android.fhir.reference, PID: 10872
    java.lang.NullPointerException
        at com.google.android.fhir.reference.PatientListViewModel.getSearchResults(PatientListViewModel.kt:77)
        at com.google.android.fhir.reference.PatientListViewModel$getSearchResults$1.invokeSuspend(Unknown Source:12)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7397)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:935)

Component
Reference App

To Reproduce
Start the reference app

Expected behavior
The app not to crash

Screenshots
If applicable, add screenshots to help explain your problem.

Smartphone (please complete the following information):

• Device: HMD Global Nokia 6.1
• Android version: 10
• Build number: 00WW_4_15C_SP11
• Version: N/A

Additional context
I think this is caused by a race condition between the two queries that are executed on view model initialisation.

• Search Patients
• Count Patients

On line 77 the result of the Count Patients Query is being used to limit the result of the Search Patients Query.

I am guessing the desired behaviour here is to limit the number of Patients displayed and then page through the remaining Patients, rather than using the result of the count query to limit the search results.

Would you like to work on the issue?
I can work on this issue if desired.

[Tarun-Bhardwaj]

Thanks @trevorgowing , the bug has been assigned to you.

[bausmeier]

@trevorgowing Have you managed to take a look at this yet, or can I jump on it?

[trevorgowing]

@bausmeier No, I have not tackled it yet. It is on my list but if it is blocking you, are you welcome to tackle it and then I can review and test it for you.

[bausmeier]

Okay I'll take it over then. I've got a fix locally, just need to commit and open a PR.