BindingSource.SortDescriptions doesn't return null
BindingSource.SortDescriptions has been updated to return an empty ListSortDescriptionCollection instead of null if the data source is not an IBindingListView.
Version introduced
.NET 9 Preview 1
Previous behavior
Previously, BindingSource.SortDescriptions returned null if the data source wasn't an IBindingListView.
New behavior
Starting in .NET 9, BindingSource.SortDescriptions returns an empty ListSortDescriptionCollection if the data source is not an IBindingListView.
Change category
This change is a behavioral change.
Reason for change
The previous behavior was incorrect.
BindingSource.SortDescriptions has historically returned null if the data source was not an IBindingListView. However BindingSource.SortDescriptions implements IBindingListView.SortDescriptions, whose return type is non-nullable. To align with the interface it implements, BindingSource.SortDescriptions was changed to return an empty ListSortDescriptionCollection instead.
Recommended action
If your code expects null from BindingSource.SortDescriptions for any reason, update your code to expect an empty ListSortDescriptionCollection instead.
Affected APIs
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