I am trying to compare component diagrams with the help of EMF compare. I created a simple UML component diagram using Sirius and UML designer.
However, when I then compare the representations.aird file with an older version of it (in which I moves all the component to a new location), all the components and classes have red crosses in the left corner. What is the cause of this problem?
I have noticed with Papyrus that when only the notation (diagram) changes, then the comparison editor does not load the underlying semantic model (*.uml) that the notation visualizes. This causes a bizarre presentation of the diagram because all of its references to the semantic model ends up being unresolved proxies. The diagram looks quite broken.
Probably the situation is similar in the Sirius context, because this restriction of resource loading to only resources that actually are different is not unique to Papyrus but is a core behaviour.