Android support lib 25 will crash with a NullPointerException if shared element fragment transitions are used and the backstack is cleared before showing the next fragment.
The offending method is located in FragmentTransitionCompat21.captureTransitioningViews,
which attempts to check view visibility without first verifying that the view still exists.
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Create an activity to host 3 fragments required to reproduce this crash. This activity should use a layout with a fragment container (R.id.fragmentContainer) to host the active fragment.
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Add fragment 1 to the activity's layout (R.id.fragmentContainer) during onCreate. DO NOT add this transaction to the backstack.
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Replace the current fragment in the layout (R.id.fragmentContainer) with fragment 2 using a shared element transition and add this transaction to the backstack.
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Pop all fragments that have been added to the backstack using flag POP_BACK_STACK_INCLUSIVE
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Replace the current fragment in the layout (R.id.fragmentContainer) with fragment 3 and add this transaction to the backstack.
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CRASH
Fragment transactions must call setAllowOptimization(true) before commit
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getVisibility()' on a null object reference
at android.support.v4.app.FragmentTransitionCompat21.captureTransitioningViews(FragmentTransitionCompat21.java:364)
at android.support.v4.app.FragmentTransition.configureEnteringExitingViews(FragmentTransition.java:901)
at android.support.v4.app.FragmentTransition.access$000$97c744e(FragmentTransition.java:37)
at android.support.v4.app.FragmentTransition.access$400(FragmentTransition.java:37)
at android.support.v4.app.FragmentTransition.access$300(FragmentTransition.java:37)
at android.support.v4.app.FragmentTransition.access$100(FragmentTransition.java:37)
at android.support.v4.app.FragmentTransition.access$200$5a6982c5(FragmentTransition.java:37)
at android.support.v4.app.FragmentTransition$2.run(FragmentTransition.java:367)
at android.support.v4.app.OneShotPreDrawListener.onPreDraw(OneShotPreDrawListener.java:64)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:921)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2164)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1191)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6642)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777)
at android.view.Choreographer.doCallbacks(Choreographer.java:590)
at android.view.Choreographer.doFrame(Choreographer.java:560)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:763)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5942)
at java.lang.reflect.Method.invoke(Method.java:-2)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)