[Bug] Scrolling CollectionView(with footer) to the last item throws System.ArgumentOutOfRangeException

[BartoszKopec]

Description

CollectionView, when vertical scrolling to the last item by developer in Android emulator, throws an System.ArgumentOutOfRangeException:
'Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index'

Steps to Reproduce

0. Using MVVM and Xamarin.Forms 4.2.0.673161-pre3
1. ContentPage with ContentView (with ControlTemplate in it)
2. CollectionView in ContentView
3. Some items in ItemsSource (MVVM)

Expected Behavior

Not throwing an exception and correct using of Scrolled event

Actual Behavior

Throws an exception System.ArgumentOutOfRangeException: 'Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index'

Basic Information

• Version with issue: Xamarin.Forms 4.2.0.673161-pre3
• Last known good version: Xamarin.Forms 4.1
• IDE: Visual Studio 2019 Community 16.2.1
• Platform Target Frameworks:
  • iOS:
  • Android: 9.0
  • UWP:
• Android Support Library Version: 28.0.0.1
• Nuget Packages:
• Affected Devices:

Screenshots

Reproduction Link

[jfversluis]

Would it be possible to add a reproduction project so we can see what is going on?

Thanks!

[BartoszKopec]

Would it be possible to add a reproduction project so we can see what is going on?

Thanks!

Reproduction project is here: https://github.com/BartoszKopec/ReproductionMobile
I found that the exception is when CollectionView has a footer just like in reproduction.
It is in MainPage.xaml (line 66) here
When there isn't footer, scrolling works very well.

[hartez]

I'm betting this is another aspect of #7102.