Crash on an null object reference in showAlignBottom (Balloon.java:2557)

[DevHugo]

Please complete the following information:

• Library Version [e.g. v1.0.0] : 1.4.0
• Affected Device(s) : Not relevant but all manufacturer: Motorola ( moto g(8) power lite, g6, G5S), Samsung (Galaxy S10+, Galaxy J5 Prime), Xiaomi, Huawei, ... . Android 8 to Android 11.

Describe the Bug:

First, I just wanted to say a big thank you for your work.

It not something that happen often like less than one hundred crash per day. So we are searching something edge case here.

Fatal Exception: java.lang.NullPointerException: Attempt to read from field 'int android.view.ViewGroup$LayoutParams.width' on a null object reference
       at android.widget.PopupWindow.alignToAnchor(PopupWindow.java:2680)
       at android.widget.PopupWindow.access$000(PopupWindow.java:114)
       at android.widget.PopupWindow$1.onViewAttachedToWindow(PopupWindow.java:258)
       at android.view.View.dispatchAttachedToWindow(View.java:19867)
       at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3597)
       at android.view.ViewGroup.addViewInner(ViewGroup.java:5370)
       at android.view.ViewGroup.addView(ViewGroup.java:5156)
       at android.view.ViewGroup.addView(ViewGroup.java:5096)
       at androidx.recyclerview.widget.RecyclerView$5.addView(RecyclerView.java:856)
       at androidx.recyclerview.widget.ChildHelper.addView(ChildHelper.java:107)
       at androidx.recyclerview.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:8601)
       at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8559)
       at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8547)
       at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1641)
       at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1587)
       at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:665)
       at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4134)
       at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3851)
       at androidx.recyclerview.widget.RecyclerView.consumePendingUpdateOperations(RecyclerView.java:1867)
       at androidx.recyclerview.widget.RecyclerView.scrollByInternal(RecyclerView.java:1936)
       at androidx.recyclerview.widget.RecyclerView.scrollBy(RecyclerView.java:1812)
       at androidx.recyclerview.widget.RecyclerView$LayoutManager.requestChildRectangleOnScreen(RecyclerView.java:9913)
       at androidx.recyclerview.widget.RecyclerView$LayoutManager.requestChildRectangleOnScreen(RecyclerView.java:9886)
       at androidx.recyclerview.widget.RecyclerView.requestChildRectangleOnScreen(RecyclerView.java:2938)
       at android.view.View.requestRectangleOnScreen(View.java:7748)
       at android.widget.PopupWindow.findDropDownPosition(PopupWindow.java:1883)
       at android.widget.PopupWindow.showAsDropDown(PopupWindow.java:1458)
       at android.widget.PopupWindow.showAsDropDown(PopupWindow.java:1420)
       at com.skydoves.balloon.Balloon$showAlignBottom$$inlined$show$1.run(Balloon.java:2557)
       at android.os.Handler.handleCallback(Handler.java:900)
       at android.os.Handler.dispatchMessage(Handler.java:103)
       at android.os.Looper.loop(Looper.java:219)
       at android.app.ActivityThread.main(ActivityThread.java:8393)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1055)

Hypothesis: the stacktrace seems to show that in the method showAlignBottom, the show callback is called. This callback is called after anchor.post method. I was asking myself, the check of !isShowing && !destroyed && !context.isFinishing && bodyWindow.contentView.parent == null && ViewCompat.isAttachedToWindow(anchor) should be inside the anchor.post method or just before calling the callback.
I don't know the code base and I would really appreciate your insight :)

Expected Behavior:

Not crash :P

[skydoves]

Hey @DevHugo, I'm sorry for replying late.
It's released a new snapshot 1.4.1-SNAPSHOT, would you please build with this version?
Thanks for reporting this issue!

[DevHugo]

Thanks !

Since we can not reproduce it easily, I just merged the pr with the updated version of the lib. I will keep you inform if it has fixed the issue when we release a new version in a few days in production :)

[skydoves]

Hey @DevHugo,
Do you have any news? 😄