DockingManager: ModelChange event happens before new LayoutDocumentItem is added

[striveprover]

When switched our project from .Net framework 4.6.1 to 4.7.2, the ApplyStyleToLayoutItem routine in Xceed.Wpf.AvalonDock.DockingManager causes a ModelChange event. Handling the event requires that the new LayoutDocumentItem is in the DockingManager's _layoutItems list. Unfortunately, the new LayoutDocumentItem is only added after ApplyStyleToLayoutItem completes.

The handler for ModelChange event in LayoutDocumentTabItem fails to set LayoutItem property and its CloseCommand no longer executes. Also, the item appears blank. Deselecting and reselecting allows its content to show, but does not fix the CloseCommand.

To be clear, we switched the .Net framework only in our projects and not in the Avalon dock project.

The fix appears to be to re-order the two lines (in two places) in Xceed.Wpf.AvalonDock.DockingManager.cs as shown below.

       _layoutItems.Add( layoutItem );
      ApplyStyleToLayoutItem( layoutItem );

[XceedBoucherS]

Hi,
Can you submit a sample showing the issue so we can test it the same way as you ?
Thank you.

[striveprover]

As you might expect the real project is quite complex and I cannot share it. But I don't understand the Avalon Dock well enough to cause ApplyStyleToLayoutItem to run. So the radically trimmed down version that I mocked up doesn't cause the behavior.