NPE with Activity#isChangingConfigurations

[jbiral]

When the app is stopped and restarted quickly, I intermittently get into this state:

Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.app.Activity.isChangingConfigurations()' on a null object reference
       at com.hannesdorfmann.mosby3.mvp.conductor.delegate.MvpConductorLifecycleListener.preDestroyView(MvpConductorLifecycleListener.java:73)
       at com.bluelinelabs.conductor.Controller.removeViewReference(Controller.java:898)
       at com.bluelinelabs.conductor.Controller.detach(Controller.java:886)
       at com.bluelinelabs.conductor.Controller$8.onDetached(Controller.java:965)
       at com.bluelinelabs.conductor.internal.ViewAttachHandler.reportDetached(ViewAttachHandler.java:103)
       at com.bluelinelabs.conductor.internal.ViewAttachHandler.onViewDetachedFromWindow(ViewAttachHandler.java:58)
       at android.view.View.dispatchDetachedFromWindow(View.java:16782)
       at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:3429)
       at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:3421)
       at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:3421)
       at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:3421)
       at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:3421)
       at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:3421)
       at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:3421)
       at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:3421)
       at android.view.ViewRootImpl.dispatchDetachedFromWindow(ViewRootImpl.java:3718)
       at android.view.ViewRootImpl.doDie(ViewRootImpl.java:6691)
       at android.view.ViewRootImpl.die(ViewRootImpl.java:6668)
       at android.view.WindowManagerGlobal.removeViewLocked(WindowManagerGlobal.java:476)
       at android.view.WindowManagerGlobal.removeView(WindowManagerGlobal.java:414)
       at android.view.WindowManagerImpl.removeViewImmediate(WindowManagerImpl.java:128)
       at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:4683)
       at android.app.ActivityThread.-wrap7(ActivityThread.java)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1703)
       at android.os.Handler.dispatchMessage(Handler.java:102)
       at android.os.Looper.loop(Looper.java:154)
       at android.app.ActivityThread.main(ActivityThread.java:6776)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)

I don't think there is much I can do since it seems to be internal to the library. Could you please investigate? This might be related to Mosby too, I will create an issue for it as well.

[EricKuck]

I've been trying to reproduce this for a while now and haven't had any luck. Do you have any additional details or steps I can take to see it happen?

[sockeqwe]

I have seen this issue too but couldn't reproduce it ...

Basically activity.getController() returns null in preDestroyView() sometimes for very few users (3 of 700 users). Unfortunately I don't know when this happens.

Here is the crashlytics link:
http://crashes.to/s/5169854fdb5

and here is the source code of the app:
https://github.com/OpenConference/DroidconBerlin2017

[EricKuck]

This should be fixed with #629. Feel free to reopen if that's not the case.