icsharpcode/SharpDevelop — pull request #510 by gumme (2014-07-02 13:49:06+00:00)
Title: StackPanel no longer removes properties that are used in the panel.

If copying an element in a StackPanel and then pasting it in the same or another StackPanel you want to get Margin and alignment properties with you, only annoying if it resets them. Blend and Visual Studio also keeps the properties in this scenario.