Strange ArrayIndexOutOfBoundsException in android.support.v4.app.ActivityCompat.OnRequestPermissionsResultCallback

Question

I received a strange out of bounds exception in the Play Store console relating to the android.support.v4.app.ActivityCompat.OnRequestPermissionsResultCallback

java.lang.ArrayIndexOutOfBoundsException: length=0; index=0
    at com.example.MyFragmentActivity.onRequestPermissionsResult(MyFragmentActivity.java:2068)
    at android.app.Activity.requestPermissions(Activity.java:4163)
    at android.support.v4.app.ActivityCompatApi23.requestPermissions(ActivityCompat23.java:32)
    at android.support.v4.app.ActivityCompat.requestPermissions(ActivityCompat.java:316)
    at com.example.MyFragmentActivity.onConnected(MyFragmentActivity.java:2048)
    at com.google.android.gms.common.internal.zzk.zzk(Unknown Source)
    at com.google.android.gms.common.api.internal.zzj.zzi(Unknown Source)
    at com.google.android.gms.common.api.internal.zzh.zzpx(Unknown Source)
    at com.google.android.gms.common.api.internal.zzh.onConnected(Unknown Source)
    at com.google.android.gms.common.api.internal.zzl.onConnected(Unknown Source)
    at com.google.android.gms.common.api.internal.zzc.onConnected(Unknown Source)
    at com.google.android.gms.common.internal.zzj$zzg.zzqL(Unknown Source)
    at com.google.android.gms.common.internal.zzj$zza.zzc(Unknown Source)
    at com.google.android.gms.common.internal.zzj$zza.zzw(Unknown Source)
    at com.google.android.gms.common.internal.zzj$zzc.zzqN(Unknown Source)
    at com.google.android.gms.common.internal.zzj$zzb.handleMessage(Unknown Source)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:158)
    at android.app.ActivityThread.main(ActivityThread.java:7229)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

This is my onRequestPermissionsResult implementation

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case REQUEST_CODE_ASK_LOCATION_PERMISSIONS:
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission Granted
                if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                    mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
                }
                startLocationUpdates();
            } else {
                // Permission Denied
            }
            break;
        default:
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}

Line 2068 is this:

if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {

I believe it's claiming grantResults length is zero which is why the java.lang.ArrayIndexOutOfBoundsException is thrown. According to the documentation

int: The grant results for the corresponding permissions which is either PERMISSION_GRANTED or PERMISSION_DENIED. Never null.

grantResults will not be null, but doesn't say anything about it not containing a value either. Furthermore it seems like the callback will contain at least one value, either PERMISSION_GRANTED or PERMISSION_DENIED. Is this a bug or am I misunderstanding the documentation?

Answer 1

Documentation about permissions says

If request is cancelled, the result arrays are empty.

And it seems to be your situation, so you have to check first if the array is not empty:

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case REQUEST_CODE_ASK_LOCATION_PERMISSIONS:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission Granted
                if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                    mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
                }
                startLocationUpdates();
            } else {
                // Permission Denied
            }
            break;
        default:
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}

Answer 2

Kotlin code for check Permission & Fix this error: It's better to check size of IntArray with .isNotEmpty() in Kotlin.

 override fun onRequestPermissionsResult(
    requestCode: Int, permissions: Array<out String>,
    grantResults: IntArray
) {
    when (requestCode) {
        PERMISSIONS_REQUEST_PICK_IMAGE_GALLERY -> {
            if (grantResults.isNotEmpty()  &&  grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                choosePhotoFromGallary()
            } else  //Permission Denied
                //  toast("Permission must be granted in order to...")
        }
        PERMISSIONS_REQUEST_TAKE_PICTURE_CAMERA -> {
            if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                takePhotoFromCamera()
            } else  //Permission Denied
                //  toast("Permission must be granted in order to ...")
        }
    } // when
} // fun