position in `fun isStickyHead(position: Int)` larger than models size.

I want a summary model to be the sticky header so I added the following check.

override fun isStickyHeader(position: Int): Boolean {
    return adapter.getModelAtPosition(position).let { it is SummaryModel }
}

I noticed that after the state of this view changed, under some circumstances the view would crash. Through debugging I found that the position that passed into this function was larger than the count of the models. I have to do a check like this:

override fun isStickyHeader(position: Int): Boolean {
    return position < adapter.copyOfModels.size  && adapter.getModelAtPosition(position).let { it is SummaryModel }
}

However, I feel pretty weird about it. I wonder if it is a bug in this library?

[samuelchou]

I encountered the similar problem, except when isStickyHeader is called, the position value it passed is negative.

I’m using Epoxy 4.6.4.

Fatal Exception: java.lang.IndexOutOfBoundsException: Invalid item position -88(-88). Item count:94 com.airbnb.epoxy.EpoxyRecyclerView{c9f6fc8 VFED..... ......ID 0,816-1080,2631 #7f080199 app:id/itemContainer}, adapter:com.airbnb.epoxy.EpoxyControllerAdapter@e3de88d, layout:com.airbnb.epoxy.stickyheader.StickyHeaderLinearLayoutManager@7452a42, context:dagger.hilt.android.internal.managers.ViewComponentManager$FragmentContextWrapper@7100797
       at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6326)
       at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6300)
       at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6296)
       at com.airbnb.epoxy.stickyheader.StickyHeaderLinearLayoutManager.createStickyHeader(StickyHeaderLinearLayoutManager.kt:283)
       at com.airbnb.epoxy.stickyheader.StickyHeaderLinearLayoutManager.updateStickyHeader(StickyHeaderLinearLayoutManager.kt:253)
       at com.airbnb.epoxy.stickyheader.StickyHeaderLinearLayoutManager.onLayoutChildren(StickyHeaderLinearLayoutManager.kt:111)
       at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4309)
       at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:4012)
       // ...

So I decided to use more safe-condition in isStickyHeader:

override fun isStickyHeader(position: Int): Boolean {
    return if (adapter.itemCount <= position || position < 0) {
        val exception = IndexOutOfBoundsException("Size: ${adapter.itemCount}, called: $position")
        Log.w(
            TAG, "isStickyHeader: called at illegal position. IGNORED and treat as viewed as not-header.",
            exception
        )
        FirebaseCrashlytics.getInstance().recordException(exception)
        false
    } else {
        adapter.getModelAtPosition(position) is MyStickyHeaderBindingModel_
    }
}

I’ll just leave it here to warn future users. (And to wait for fix, of course.)

[WessimBetclic]

Hello ! Any news on this particular bug ?