IllegalStateException in RecyclerView: Two different ViewHolders have the same stable ID

[loremattei]

Fatal Exception: java.lang.IllegalStateException: Two different ViewHolders have the same stable ID. Stable IDs in your adapter MUST BE unique and SHOULD NOT change.
 ViewHolder 1:ViewHolder{425cbd80 position=20 id=72545603, oldPos=-1, pLpos:-1 not recyclable(1)} 
 View Holder 2:ViewHolder{426f6090 position=19 id=72545603, oldPos=-1, pLpos:-1} android.support.v7.widget.RecyclerView{43187c58 VFED.V.. ......ID 0,0-480,606 #7f090420 app:id/recycler_view}, adapter:org.wordpress.android.ui.reader.adapters.ReaderSiteSearchAdapter@43090348, layout:android.support.v7.widget.LinearLayoutManager@43149848, context:org.wordpress.android.ui.main.WPMainActivity@41d736f0
       at android.support.v7.widget.RecyclerView.handleMissingPreInfoForChangeError(RecyclerView.java:3946)
       at android.support.v7.widget.RecyclerView.dispatchLayoutStep3(RecyclerView.java:3870)
       at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3540)
       at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:4082)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:606)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1083)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.support.design.widget.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:132)
       at android.support.design.widget.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:42)
       at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1361)
       at android.support.design.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:894)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1083)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1083)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
       at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1083)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
       at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
       at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
       at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1791)
       at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1635)
       at android.widget.LinearLayout.onLayout(LinearLayout.java:1544)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
       at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
       at com.android.internal.policy.DecorView.onLayout(DecorView.java:764)
       at android.view.View.layout(View.java:19685)
       at android.view.ViewGroup.layout(ViewGroup.java:6077)
       at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2538)
       at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2254)
       at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1434)
       at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6868)
       at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1026)
       at android.view.Choreographer.doCallbacks(Choreographer.java:838)
       at android.view.Choreographer.doFrame(Choreographer.java:769)
       at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1012)
       at android.os.Handler.handleCallback(Handler.java:790)
       at android.os.Handler.dispatchMessage(Handler.java:99)
       at android.os.Looper.loop(Looper.java:171)
       at android.app.ActivityThread.main(ActivityThread.java:6635)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)

5ae0fd9b638393737a3c3ea5-fabric

[rachelmcr]

Adding a high priority label as this is one of our most frequent crashes.

[hypest]

Updated the description to include some more specific info from the crash.

[hypest]

I think I found a condition that can probably lead to the crash:

1. Go to the Reader
2. Have "Followed Sites" as the selected Reader section
3. Tap on the search on the right (the magnifier glass icon)
4. Type a query, for example: test
5. Select the "Sites" tab from the results
6. Scroll to the end of the list to trigger infinite scroll. Notice the last item while the new search is ongoing.
7. Scroll a couple of items down and notice that the last item of the first "page" is repeated, effectively having the same item/site twice on the list

This means that there are two items with the same feed id so, the getItemId() implementation here will produce the same id for two different list positions. That's a problematic situation and most probably can lead to the crash at hand, even though the occurrence of it depends on more conditions too.

Will produce a PR to fix the duplicate list item.

[mzorz]

nice find here!