IssueTracker

Component used: Navigation
Version used: 2.8.7

In version 2.8.6, this change was included: [https://android-review.googlesource.com/c/platform/frameworks/support/+/3461892](https://android-review.googlesource.com/c/platform/frameworks/support/+/3461892). Before this change, it was possible to use the argument of the parent navGraph as a label, as long as the navigation action that caused the navigation included the argument. With the newer versions this now results in a NullPointerException on line 664 of the `navigation/navigation-common/src/main/java/androidx/navigation/NavDestination.kt` because of the non-null assertion of the `argType`.

I do think that the behavior I used (or probably more accurately; abused) until now, was probably a Bug and I should never have used it. I will therefore change my code to get rid of this use of a non-feature.  
I do however think that this should still be looked into again, as it is evidently possible for the `argType` value to be null, because an argument was part of the bundle but not part of the `_arguments` Map.  
Also, this issue can be seen as a feature request. I would like for the feature I already incorrectly used, to be added properly. Should I create a separate issue for this feature request?