[Proppy Integration] Does not handle ValueSource.Unset

[CartBlanche]

See Gif for repro steps...

Expected behaviour is that when Reset is called, it rests to whatever the default value is for that property.

Also looking at all the filled property button circles on the right, it looks like all the properties have had their default values changed. Only properties that are different to the default should be filled, other properties that have not been changed, should have an unfilled property button circle.

VS bug #1005343

[CartBlanche]

Possibly here -

monodevelop/main/src/addins/MonoDevelop.DesignerSupport/MonoDevelop.DesignerSupport/NativePropertyEditor/ComponentModelObjectEditor.cs

Line 117 in 4bdfc25

public Task SetValueAsync<T> (IPropertyInfo propertyInfo, ValueInfo<T> value, PropertyVariation variations = null)

This might help...
https://github.com/xamarin/Xamarin.PropertyEditing/blob/38105d0dcc46082d5d249de92ab188d829ea4dc1/Xamarin.PropertyEditing.Tests/MockObjectEditor.cs#L191