Reuse: Remove all references before adding elemtn to library

before adding an element to a library, all references directing
"outside" of the component are removed, since those would break.
Containment relations are kept, since these elements are reused with the
parent.

Issue-ref: 4346
Issue-URL: af3#4346



Signed-off-by: Andreas Bayha <bayha@fortiss.org>

org.fortiss.tooling.ext.reuse/src/org/fortiss/tooling/ext/reuse/service/.ratings

 IReuseProvider.java 18d293f7f1f072883188f16fb6eeb52c8d6042cf GREEN
 IReuseProviderService.java bcc70de0bb8d39c330e3a25d884abc7092dc1b7e GREEN
 LayoutedReuseProviderBase.java b0e4ce3cda818b0723ec37b925a4c4c3d0c41909 GREEN
-ReuseProviderBase.java ac47f5ecafed0bdef6ef5183c7194aa756f723fd GREEN
+ReuseProviderBase.java c956ba13df1b7b5c8dbd7cd1a9205a06b5cebba1 YELLOW
 ReuseProviderService.java c4ef33283002d6dac6167f9c6c8f71d2c2ce39d1 GREEN

org.fortiss.tooling.ext.reuse/src/org/fortiss/tooling/ext/reuse/service/ReuseProviderBase.java

@@ -20,9 +20,11 @@ import static org.fortiss.tooling.ext.variability.util.VariabilityUtils.getOptVa
 import static org.fortiss.tooling.kernel.utils.EcoreUtils.replaceEObjectReferences;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 
 import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.EReference;
 import org.fortiss.tooling.base.model.element.IHierarchicElement;
 import org.fortiss.tooling.base.model.element.IHierarchicElementContainer;
 import org.fortiss.tooling.base.model.element.IModelElement;
@@ -48,6 +50,9 @@ public class ReuseProviderBase<T extends EObject> implements IReuseProvider<T> {
 		if(reuseElement instanceof IModelElement) {
 			removeVariabilitySpecifications((IModelElement)reuseElement);
 		}
+
+		removeExternalReferences(reuseElement);
+
 		return true;
 	}
 
@@ -124,4 +129,35 @@ public class ReuseProviderBase<T extends EObject> implements IReuseProvider<T> {
 			}
 		}
 	}
+
+	/**
+	 * Recursively removes all external (i.e. non-containment) reference targets from this and all
+	 * contained {@link EObject}s.
+	 * 
+	 * @param eObj
+	 *            The {@link EObject} for which all reference targets shall be removed.
+	 */
+	@SuppressWarnings("unchecked")
+	private void removeExternalReferences(EObject eObj) {
+		for(EReference ref : eObj.eClass().getEReferences()) {
+			Object refTarget = eObj.eGet(ref);
+
+			if(refTarget == null) {
+				continue;
+			}
+
+			if(ref.isContainment()) {
+				// Containment relations must not be removed. Yet, references of childs need to be
+				// removed recursively.
+				if(refTarget instanceof Collection<?>) {
+					((Collection<EObject>)refTarget).stream()
+							.forEach(t -> removeExternalReferences(t));
+				} else {
+					removeExternalReferences((EObject)refTarget);
+				}
+			} else {
+				eObj.eSet(ref, null);
+			}
+		}
+	}
 }