last DataGridCell gets clipped if RowHeaders are visible.

[timunie]

Describe the bug
This is a stange thing. If I enable RowHeaders and not all columns fit into the space (horizontal scroll viewer) the last Cell of each row is clipped or hidden by a rectangle (see Screenshot)

To Reproduce
Steps to reproduce the behavior:

1. Go to ControlCatalog ► DataGridPage
2. change the XAML like below
   • RowHeaderWidth="40" is important
   • No column width is * is important
3. resize the columns until the horizontal scrollviewer is visible
4. Scroll to the right end
5. See the las cell is clipped or hidden by a rectangle

Code

<DataGrid Name="dataGrid1" Margin="12" CanUserResizeColumns="True" CanUserReorderColumns="True" CanUserSortColumns="True" HeadersVisibility="All"
          RowBackground="#1000"
          RowHeaderWidth="40"
          AlternatingRowBackground="#1fff">
  <DataGrid.Columns>
    <!-- Using HeaderTemplate -->
    <DataGridTextColumn Header="Country" HeaderTemplate="{StaticResource Demo.DataTemplates.CountryHeader}" Binding="{Binding Name}" />
    <!-- CompiledBinding example of usage. -->
    <DataGridTextColumn Header="Region" Binding="{CompiledBinding Region}"  x:DataType="local:Country" />
    <DataGridTextColumn Header="Population" Binding="{Binding Population}"  />
    <DataGridTextColumn Header="Area" Binding="{Binding Area}" />
    <DataGridTextColumn Header="GDP" Binding="{Binding GDP}" CellStyleClasses="gdp"
                        MinWidth="200"
                        IsVisible="{Binding #ShowGDP.IsChecked}"/>
  </DataGrid.Columns>
</DataGrid>

Expected behavior
No cell is clipped

Screenshots

Desktop (please complete the following information):

• OS: Windows 10
• Version latest master, 0.10.15

Additional context
I haven't find the root cause yet. Any hint is welcome.

[timunie]

Update: I've investigated this issue further. And I've noticed, that if you are using groups the group header will overlay the row headers. Is this maybe related?

I've still not found a solution for this issue unfortunately.

[timunie]

Update 2: I finally think I found the issue. Will send a PR soon.