[484577] Make sure 'requires' are on the same side

Former implementation caused diffs from different sides to be linked by
'requires/requiredBy' or 'refines/refinedBy' references, which does not
make sense and caused erroneous behavior.

Bug: 484577
Change-Id: Ia23a41a4edd8d4336555a1423ce1d56f529662c9
Signed-off-by: Laurent Delaigue <laurent.delaigue@obeo.fr>

19 files changed, 136 insertions, 57 deletions

diff --git a/plugins/org.eclipse.emf.compare.diagram.papyrus/src/org/eclipse/emf/compare/diagram/papyrus/internal/PapyrusDiagramPostComparison.java b/plugins/org.eclipse.emf.compare.diagram.papyrus/src/org/eclipse/emf/compare/diagram/papyrus/internal/PapyrusDiagramPostComparison.java
index 7044ee137..bdf167c71 100644
--- a/plugins/org.eclipse.emf.compare.diagram.papyrus/src/org/eclipse/emf/compare/diagram/papyrus/internal/PapyrusDiagramPostComparison.java
+++ b/plugins/org.eclipse.emf.compare.diagram.papyrus/src/org/eclipse/emf/compare/diagram/papyrus/internal/PapyrusDiagramPostComparison.java
@@ -10,9 +10,6 @@
  *******************************************************************************/
 package org.eclipse.emf.compare.diagram.papyrus.internal;
 
-import com.google.common.collect.Sets;
-
-import java.util.Collections;
 import java.util.Set;
 
 import org.eclipse.emf.compare.Comparison;
@@ -70,7 +67,11 @@ public class PapyrusDiagramPostComparison implements Runnable {
 			Set<Diff> diffs = indexer.getEquivalentDiffs(key);
 			if (diffs.size() > 1) {
 				for (Diff diff : diffs) {
-					diff.getRequires().addAll(Sets.difference(diffs, Collections.singleton(diff)));
+					for (Diff other : diffs) {
+						if (other != diff && other.getSource() == diff.getSource()) {
+							diff.getRequires().add(other);
+						}
+					}
 				}
 			}
 		}
diff --git a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/CoordinatesChangeFactory.java b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/CoordinatesChangeFactory.java
index bff0c6a51..1547010de 100644
--- a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/CoordinatesChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/CoordinatesChangeFactory.java
@@ -89,7 +89,9 @@ public class CoordinatesChangeFactory extends NodeChangeFactory {
 	@Override
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
 		if (extensionKind == DifferenceKind.CHANGE) {
-			extension.getRefinedBy().addAll(getAllDifferencesForChange(refiningDiff));
+			extension.getRefinedBy().addAll(
+					Collections2.filter(getAllDifferencesForChange(refiningDiff), fromSide(extension
+							.getSource())));
 		}
 	}
 
diff --git a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/DiagramChangeFactory.java b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/DiagramChangeFactory.java
index 67db74e1e..e63e3404d 100644
--- a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/DiagramChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/DiagramChangeFactory.java
@@ -11,6 +11,7 @@
 package org.eclipse.emf.compare.diagram.internal.factories.extensions;
 
 import com.google.common.base.Predicate;
+import com.google.common.collect.Collections2;
 
 import org.eclipse.emf.compare.Comparison;
 import org.eclipse.emf.compare.Diff;
@@ -20,6 +21,7 @@ import org.eclipse.emf.compare.diagram.internal.extensions.DiagramChange;
 import org.eclipse.emf.compare.diagram.internal.extensions.DiagramDiff;
 import org.eclipse.emf.compare.diagram.internal.extensions.ExtensionsFactory;
 import org.eclipse.emf.compare.diagram.internal.factories.AbstractDiagramChangeFactory;
+import org.eclipse.emf.compare.utils.EMFComparePredicates;
 import org.eclipse.emf.compare.utils.MatchUtil;
 import org.eclipse.emf.compare.utils.ReferenceUtil;
 import org.eclipse.emf.ecore.EObject;
@@ -69,13 +71,19 @@ public class DiagramChangeFactory extends AbstractDiagramChangeFactory {
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
 		// Macroscopic change on a diagram is refined by the unit main change and all unit children related
 		// changes.
-		extension.getRefinedBy().add(refiningDiff);
-		extension.getRefinedBy().addAll(getAllContainedDifferences(refiningDiff));
+		if (refiningDiff.getSource() == extension.getSource()) {
+			extension.getRefinedBy().add(refiningDiff);
+			extension.getRefinedBy().addAll(
+					Collections2.filter(getAllContainedDifferences(refiningDiff), EMFComparePredicates
+							.fromSide(extension.getSource())));
+		}
 	}
 
 	/**
 	 * {@inheritDoc}
-	 * @see org.eclipse.emf.compare.internal.postprocessor.factories.AbstractChangeFactory#fillRequiredDifferences(org.eclipse.emf.compare.Comparison, org.eclipse.emf.compare.Diff)
+	 * 
+	 * @see org.eclipse.emf.compare.internal.postprocessor.factories.AbstractChangeFactory#fillRequiredDifferences(org.eclipse.emf.compare.Comparison,
+	 *      org.eclipse.emf.compare.Diff)
 	 */
 	@Override
 	public void fillRequiredDifferences(Comparison comparison, Diff extension) {
diff --git a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/EdgeChangeFactory.java b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/EdgeChangeFactory.java
index 7a15bb30e..fa730153f 100644
--- a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/EdgeChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/EdgeChangeFactory.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2013 Obeo.
+ * Copyright (c) 2013, 2015 Obeo.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -11,6 +11,7 @@
 package org.eclipse.emf.compare.diagram.internal.factories.extensions;
 
 import com.google.common.base.Predicate;
+import com.google.common.collect.Collections2;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Iterators;
 
@@ -27,6 +28,7 @@ import org.eclipse.emf.compare.ReferenceChange;
 import org.eclipse.emf.compare.diagram.internal.extensions.DiagramDiff;
 import org.eclipse.emf.compare.diagram.internal.extensions.EdgeChange;
 import org.eclipse.emf.compare.diagram.internal.extensions.ExtensionsFactory;
+import org.eclipse.emf.compare.utils.EMFComparePredicates;
 import org.eclipse.emf.compare.utils.MatchUtil;
 import org.eclipse.emf.compare.utils.ReferenceUtil;
 import org.eclipse.emf.ecore.EObject;
@@ -81,7 +83,9 @@ public class EdgeChangeFactory extends NodeChangeFactory {
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
 		super.setRefiningChanges(extension, extensionKind, refiningDiff);
 		if (extensionKind == DifferenceKind.CHANGE) {
-			extension.getRefinedBy().addAll(getAllDifferencesForChange(refiningDiff));
+			extension.getRefinedBy().addAll(
+					Collections2.filter(getAllDifferencesForChange(refiningDiff), EMFComparePredicates
+							.fromSide(extension.getSource())));
 		}
 	}
 
diff --git a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/HideFactory.java b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/HideFactory.java
index d5a2b9953..228522db0 100644
--- a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/HideFactory.java
+++ b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/HideFactory.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2013 Obeo.
+ * Copyright (c) 2013, 2015 Obeo.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -56,7 +56,9 @@ public class HideFactory extends AbstractDiagramChangeFactory {
 	 */
 	@Override
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
-		extension.getRefinedBy().add(refiningDiff);
+		if (refiningDiff.getSource() == extension.getSource()) {
+			extension.getRefinedBy().add(refiningDiff);
+		}
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/NodeChangeFactory.java b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/NodeChangeFactory.java
index 0e5d93573..399d276ce 100644
--- a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/NodeChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/NodeChangeFactory.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2013 Obeo.
+ * Copyright (c) 2013, 2015 Obeo.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -12,6 +12,7 @@ package org.eclipse.emf.compare.diagram.internal.factories.extensions;
 
 import static com.google.common.base.Predicates.and;
 import static com.google.common.base.Predicates.instanceOf;
+import static org.eclipse.emf.compare.utils.EMFComparePredicates.fromSide;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.ofKind;
 
 import com.google.common.base.Predicate;
@@ -29,6 +30,7 @@ import org.eclipse.emf.compare.diagram.internal.extensions.DiagramDiff;
 import org.eclipse.emf.compare.diagram.internal.extensions.ExtensionsFactory;
 import org.eclipse.emf.compare.diagram.internal.extensions.NodeChange;
 import org.eclipse.emf.compare.diagram.internal.factories.AbstractDiagramChangeFactory;
+import org.eclipse.emf.compare.utils.EMFComparePredicates;
 import org.eclipse.emf.compare.utils.ReferenceUtil;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.gmf.runtime.notation.Node;
@@ -76,11 +78,14 @@ public class NodeChangeFactory extends AbstractDiagramChangeFactory {
 	 */
 	@Override
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
-		// Macroscopic change on a node is refined by the unit main change and unit children related changes.
-		extension.getRefinedBy().add(refiningDiff);
-		// if (extensionKind != DifferenceKind.MOVE) {
-		extension.getRefinedBy().addAll(getAllContainedDifferences(refiningDiff));
-		// }
+		if (refiningDiff.getSource() == extension.getSource()) {
+			// Macroscopic change on a node is refined by the unit main change and unit children related
+			// changes.
+			extension.getRefinedBy().add(refiningDiff);
+			extension.getRefinedBy().addAll(
+					Collections2.filter(getAllContainedDifferences(refiningDiff), EMFComparePredicates
+							.fromSide(extension.getSource())));
+		}
 	}
 
 	/**
@@ -108,7 +113,7 @@ public class NodeChangeFactory extends AbstractDiagramChangeFactory {
 		Set<Diff> requiredExtensions = new HashSet<Diff>();
 		Set<Diff> requiringExtensions = new HashSet<Diff>();
 		final Predicate<Diff> moveReference = and(instanceOf(ReferenceChange.class),
-				ofKind(DifferenceKind.MOVE));
+				ofKind(DifferenceKind.MOVE), fromSide(extension.getSource()));
 		Collection<Diff> refiningMoves = Collections2.filter(extension.getRefinedBy(), moveReference);
 		for (Diff diff : refiningMoves) {
 			EObject target = ((ReferenceChange)diff).getValue();
diff --git a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/ShowFactory.java b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/ShowFactory.java
index e92f436b2..739a00054 100644
--- a/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/ShowFactory.java
+++ b/plugins/org.eclipse.emf.compare.diagram/src/org/eclipse/emf/compare/diagram/internal/factories/extensions/ShowFactory.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2013 Obeo.
+ * Copyright (c) 2013, 2015 Obeo.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -40,7 +40,9 @@ public class ShowFactory extends AbstractDiagramChangeFactory {
 
 	@Override
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
-		extension.getRefinedBy().add(refiningDiff);
+		if (refiningDiff.getSource() == extension.getSource()) {
+			extension.getRefinedBy().add(refiningDiff);
+		}
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/AbstractUMLChangeFactory.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/AbstractUMLChangeFactory.java
index 2f1dbb266..4370061c8 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/AbstractUMLChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/AbstractUMLChangeFactory.java
@@ -13,6 +13,7 @@ package org.eclipse.emf.compare.uml2.internal.postprocessor;
 import static com.google.common.base.Predicates.instanceOf;
 
 import com.google.common.base.Predicate;
+import com.google.common.collect.Collections2;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Iterators;
@@ -32,6 +33,7 @@ import org.eclipse.emf.compare.internal.postprocessor.factories.AbstractChangeFa
 import org.eclipse.emf.compare.internal.utils.ComparisonUtil;
 import org.eclipse.emf.compare.uml2.internal.StereotypeApplicationChange;
 import org.eclipse.emf.compare.uml2.internal.UMLDiff;
+import org.eclipse.emf.compare.utils.EMFComparePredicates;
 import org.eclipse.emf.compare.utils.MatchUtil;
 import org.eclipse.emf.compare.utils.ReferenceUtil;
 import org.eclipse.emf.ecore.EObject;
@@ -517,7 +519,9 @@ public abstract class AbstractUMLChangeFactory extends AbstractChangeFactory {
 			Predicate<Diff> p) {
 		if (lookup instanceof EObject) {
 			List<Diff> crossReferences = findCrossReferences(comparison, (EObject)lookup, p);
-			refinedExtension.getRefinedBy().addAll(crossReferences);
+			refinedExtension.getRefinedBy().addAll(
+					Collections2.filter(crossReferences, EMFComparePredicates.fromSide(refinedExtension
+							.getSource())));
 		}
 	}
 
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/UMLPostProcessor.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/UMLPostProcessor.java
index 18d1e16f9..ccba87219 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/UMLPostProcessor.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/UMLPostProcessor.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2012, 2014 Obeo.
+ * Copyright (c) 2012, 2015 Obeo.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -332,10 +332,10 @@ public class UMLPostProcessor implements IPostProcessor {
 			Comparison comparison = diff.getMatch().getComparison();
 			for (Diff superSetDiff : comparison.getDifferences(superSet)) {
 				// Only keep diffs on the same ref and value where parent matches
-				if (superSetDiff instanceof ReferenceChange
+				if (superSetDiff instanceof ReferenceChange && superSetDiff.getSource() == diff.getSource()
 						&& ((ReferenceChange)superSetDiff).getReference() == superSet
 						&& ((ReferenceChange)superSetDiff).getValue() == diff.getValue()
-						&& ((ReferenceChange)superSetDiff).getMatch() == diff.getMatch()) {
+						&& superSetDiff.getMatch() == diff.getMatch()) {
 					if (isAddOrSetDiff(diff) && isAddOrSetDiff(superSetDiff)) {
 						diff.getImplies().add(superSetDiff);
 					} else if (isDeleteOrUnsetDiff(diff) && isDeleteOrUnsetDiff(superSetDiff)) {
@@ -354,9 +354,9 @@ public class UMLPostProcessor implements IPostProcessor {
 				Comparison comparison = diff.getMatch().getComparison();
 				for (Diff superSetDiff : comparison.getDifferences(superSet)) {
 					if (superSetDiff instanceof ReferenceChange
+							&& superSetDiff.getSource() == diff.getSource()
 							&& ((ReferenceChange)superSetDiff).getReference() == superSet
-							&& ((ReferenceChange)superSetDiff).getMatch() == comparison.getMatch(diff
-									.getValue())) {
+							&& superSetDiff.getMatch() == comparison.getMatch(diff.getValue())) {
 						if (isAddOrSetDiff(diff) && isAddOrSetDiff(superSetDiff)) {
 							diff.getImplies().add(superSetDiff);
 						} else if (isDeleteOrUnsetDiff(diff) && isDeleteOrUnsetDiff(superSetDiff)) {
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/UMLOpaqueElementBodyChangeFactory.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/UMLOpaqueElementBodyChangeFactory.java
index 032ca5d76..4325da3a9 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/UMLOpaqueElementBodyChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/UMLOpaqueElementBodyChangeFactory.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2014 EclipseSource Muenchen GmbH and others.
+ * Copyright (c) 2014, 2015 EclipseSource Muenchen GmbH and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,6 +7,7 @@
  * 
  * Contributors:
  *     Philip Langer - initial API and implementation
+ *     Obeo - Prevent mixing sides in requires/implies/refines
  *******************************************************************************/
 package org.eclipse.emf.compare.uml2.internal.postprocessor.extension;
 
@@ -274,8 +275,10 @@ public class UMLOpaqueElementBodyChangeFactory extends AbstractUMLChangeFactory
 	@Override
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
 		final OpaqueElementBodyChange bodyChange = (OpaqueElementBodyChange)extension;
-		bodyChange.getRefinedBy().add(refiningDiff);
-		collectAndAddOtherRefiningDiffs(bodyChange, refiningDiff);
+		if (refiningDiff.getSource() == bodyChange.getSource()) {
+			bodyChange.getRefinedBy().add(refiningDiff);
+			collectAndAddOtherRefiningDiffs(bodyChange, refiningDiff);
+		}
 	}
 
 	/**
@@ -292,7 +295,9 @@ public class UMLOpaqueElementBodyChangeFactory extends AbstractUMLChangeFactory
 		final RefinementCollector collector = new RefinementCollector((AttributeChange)refiningDiff);
 		Iterable<Diff> collectedRefiningDiffs = collector.collect();
 		for (Diff otherRefiningDiff : collectedRefiningDiffs) {
-			bodyChange.getRefinedBy().add(otherRefiningDiff);
+			if (otherRefiningDiff.getSource() == bodyChange.getSource()) {
+				bodyChange.getRefinedBy().add(otherRefiningDiff);
+			}
 		}
 	}
 
@@ -463,7 +468,8 @@ public class UMLOpaqueElementBodyChangeFactory extends AbstractUMLChangeFactory
 		 *         otherwise.
 		 */
 		private boolean isChangeOfBodyOrLanguageAttribute(AttributeChange attributeChange) {
-			return isChangeOfOpaqueElementBodyAttribute(attributeChange) || isChangeOfOpaqueElementLanguageAttribute(attributeChange);
+			return isChangeOfOpaqueElementBodyAttribute(attributeChange)
+					|| isChangeOfOpaqueElementLanguageAttribute(attributeChange);
 		}
 
 	}
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/profile/UMLProfileApplicationChangeFactory.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/profile/UMLProfileApplicationChangeFactory.java
index 86fe4f45c..6fce0f764 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/profile/UMLProfileApplicationChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/profile/UMLProfileApplicationChangeFactory.java
@@ -110,7 +110,8 @@ public class UMLProfileApplicationChangeFactory extends AbstractUMLChangeFactory
 					final EObject eObject = stereotypeApplications.next();
 					for (Diff diff : comparison.getDifferences(eObject)) {
 						if (diff instanceof StereotypeApplicationChange
-								&& diff.getKind() == DifferenceKind.DELETE) {
+								&& diff.getKind() == DifferenceKind.DELETE
+								&& diff.getSource() == profileApplicationChange.getSource()) {
 							profileApplicationChange.getRequires().add(diff);
 						}
 					}
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLDanglingStereotypeApplicationFactory.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLDanglingStereotypeApplicationFactory.java
index 3b28e8403..ecf78a15c 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLDanglingStereotypeApplicationFactory.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLDanglingStereotypeApplicationFactory.java
@@ -71,12 +71,14 @@ public class UMLDanglingStereotypeApplicationFactory extends AbstractUMLChangeFa
 
 	@Override
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
-		extension.getRefinedBy().add(refiningDiff);
-		// Unfortunate, don't know how to set the resourceURI elsewhere than here.
-		if (refiningDiff instanceof ResourceAttachmentChange
-				&& extension instanceof DanglingStereotypeApplication) {
-			((DanglingStereotypeApplication)extension)
-					.setResourceURI(((ResourceAttachmentChange)refiningDiff).getResourceURI());
+		if (refiningDiff.getSource() == extension.getSource()) {
+			extension.getRefinedBy().add(refiningDiff);
+			// Unfortunate, don't know how to set the resourceURI elsewhere than here.
+			if (refiningDiff instanceof ResourceAttachmentChange
+					&& extension instanceof DanglingStereotypeApplication) {
+				((DanglingStereotypeApplication)extension)
+						.setResourceURI(((ResourceAttachmentChange)refiningDiff).getResourceURI());
+			}
 		}
 	}
 
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeApplicationChangeFactory.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeApplicationChangeFactory.java
index fdee6c537..890030a6c 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeApplicationChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeApplicationChangeFactory.java
@@ -120,8 +120,8 @@ public class UMLStereotypeApplicationChangeFactory extends AbstractUMLChangeFact
 					.getDifferences().iterator();
 			while (changes.hasNext()) {
 				final Diff diff = changes.next();
-				if (diff instanceof AttributeChange || diff instanceof ReferenceChange
-						|| diff instanceof ResourceAttachmentChange) {
+				if ((diff instanceof AttributeChange || diff instanceof ReferenceChange || diff instanceof ResourceAttachmentChange)
+						&& diff.getSource() == extension.getSource()) {
 					extension.getRefinedBy().add(diff);
 				}
 			}
@@ -239,7 +239,8 @@ public class UMLStereotypeApplicationChangeFactory extends AbstractUMLChangeFact
 			if (setting.getEStructuralFeature() == UMLPackage.Literals.PROFILE_APPLICATION__APPLIED_PROFILE) {
 				final ProfileApplication profileApplication = (ProfileApplication)setting.getEObject();
 				for (Diff diff : comparison.getDifferences(profileApplication)) {
-					if (diff instanceof ProfileApplicationChange && diff.getKind() == DifferenceKind.ADD) {
+					if (diff instanceof ProfileApplicationChange && diff.getKind() == DifferenceKind.ADD
+							&& diff.getSource() == stereotypeApplicationChange.getSource()) {
 						stereotypeApplicationChange.getRequires().add(diff);
 					}
 				}
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeAttributeChangeFactory.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeAttributeChangeFactory.java
index f5f8d8eb4..5d6ac4019 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeAttributeChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeAttributeChangeFactory.java
@@ -128,7 +128,9 @@ public class UMLStereotypeAttributeChangeFactory extends AbstractUMLChangeFactor
 	 */
 	@Override
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
-		extension.getRefinedBy().add(refiningDiff);
+		if (refiningDiff.getSource() == extension.getSource()) {
+			extension.getRefinedBy().add(refiningDiff);
+		}
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeReferenceChangeFactory.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeReferenceChangeFactory.java
index 6b1e3e7c5..79b6a5a25 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeReferenceChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypeReferenceChangeFactory.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2013 Obeo.
+ * Copyright (c) 2013, 2015 Obeo.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -128,7 +128,9 @@ public class UMLStereotypeReferenceChangeFactory extends AbstractUMLChangeFactor
 	 */
 	@Override
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
-		extension.getRefinedBy().add(refiningDiff);
+		if (refiningDiff.getSource() == extension.getSource()) {
+			extension.getRefinedBy().add(refiningDiff);
+		}
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypedElementChangeFactory.java b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypedElementChangeFactory.java
index d1b148208..48e5e4004 100644
--- a/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypedElementChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare.uml2/src/org/eclipse/emf/compare/uml2/internal/postprocessor/extension/stereotype/UMLStereotypedElementChangeFactory.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2014 Obeo.
+ * Copyright (c) 2014, 2015 Obeo.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -10,6 +10,7 @@
  *******************************************************************************/
 package org.eclipse.emf.compare.uml2.internal.postprocessor.extension.stereotype;
 
+import com.google.common.collect.Collections2;
 import com.google.common.collect.Lists;
 
 import java.util.Collections;
@@ -24,6 +25,7 @@ import org.eclipse.emf.compare.uml2.internal.StereotypedElementChange;
 import org.eclipse.emf.compare.uml2.internal.UMLCompareFactory;
 import org.eclipse.emf.compare.uml2.internal.postprocessor.AbstractUMLChangeFactory;
 import org.eclipse.emf.compare.uml2.internal.postprocessor.util.UMLCompareUtil;
+import org.eclipse.emf.compare.utils.EMFComparePredicates;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.util.Switch;
 import org.eclipse.uml2.uml.Element;
@@ -95,8 +97,12 @@ public class UMLStereotypedElementChangeFactory extends AbstractUMLChangeFactory
 	public void setRefiningChanges(Diff extension, DifferenceKind extensionKind, Diff refiningDiff) {
 		// super.setRefiningChanges(extension, extensionKind, refiningDiff);
 		List<StereotypeApplicationChange> stereotypeApplicationChanges = getStereotypeApplicationChanges((ReferenceChange)refiningDiff);
-		extension.getRefinedBy().addAll(stereotypeApplicationChanges);
-		extension.getRefinedBy().add(refiningDiff);
+		if (refiningDiff.getSource() == extension.getSource()) {
+			extension.getRefinedBy().add(refiningDiff);
+			extension.getRefinedBy().addAll(
+					Collections2.filter(stereotypeApplicationChanges, EMFComparePredicates.fromSide(extension
+							.getSource())));
+		}
 
 	}
 
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/internal/postprocessor/factories/AbstractChangeFactory.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/internal/postprocessor/factories/AbstractChangeFactory.java
index 061508d1a..86307cdcf 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/internal/postprocessor/factories/AbstractChangeFactory.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/internal/postprocessor/factories/AbstractChangeFactory.java
@@ -11,6 +11,7 @@
 package org.eclipse.emf.compare.internal.postprocessor.factories;
 
 import com.google.common.base.Predicate;
+import com.google.common.collect.Collections2;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Iterators;
 import com.google.common.collect.Lists;
@@ -31,6 +32,7 @@ import org.eclipse.emf.compare.ReferenceChange;
 import org.eclipse.emf.compare.ResourceAttachmentChange;
 import org.eclipse.emf.compare.internal.utils.ComparisonUtil;
 import org.eclipse.emf.compare.util.CompareSwitch;
+import org.eclipse.emf.compare.utils.EMFComparePredicates;
 import org.eclipse.emf.compare.utils.MatchUtil;
 import org.eclipse.emf.ecore.EObject;
 
@@ -66,11 +68,12 @@ public abstract class AbstractChangeFactory implements IChangeFactory {
 
 		final DifferenceKind extensionKind = getRelatedExtensionKind(input);
 		ret.setKind(extensionKind);
+		// It's important to set the source before calling setRefiningChanges()
+		// because refines/refinedBy EReferences demand diffs on the same side
+		ret.setSource(input.getSource());
 
 		setRefiningChanges(ret, extensionKind, input);
 
-		ret.setSource(input.getSource());
-
 		// FIXME: Maybe it would be better to get all conflict objects from all conflicting unit differences
 		// and
 		// create a new conflict object with these differences, to set on the macroscopic change (ret).
@@ -152,8 +155,10 @@ public abstract class AbstractChangeFactory implements IChangeFactory {
 		requiredExtensions.remove(macro);
 		requiringExtensions.remove(macro);
 
-		macro.getRequires().addAll(requiredExtensions);
-		macro.getRequiredBy().addAll(requiringExtensions);
+		macro.getRequires().addAll(
+				Collections2.filter(requiredExtensions, EMFComparePredicates.fromSide(macro.getSource())));
+		macro.getRequiredBy().addAll(
+				Collections2.filter(requiringExtensions, EMFComparePredicates.fromSide(macro.getSource())));
 	}
 
 	/**
@@ -178,8 +183,10 @@ public abstract class AbstractChangeFactory implements IChangeFactory {
 				}
 			}
 		}
-		macro.getRequires().addAll(requiredExtensions);
-		macro.getRequiredBy().addAll(requiringExtensions);
+		macro.getRequires().addAll(
+				Collections2.filter(requiredExtensions, EMFComparePredicates.fromSide(macro.getSource())));
+		macro.getRequiredBy().addAll(
+				Collections2.filter(requiringExtensions, EMFComparePredicates.fromSide(macro.getSource())));
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/req/DefaultReqEngine.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/req/DefaultReqEngine.java
index b645cc79f..6e7d595e1 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/req/DefaultReqEngine.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/req/DefaultReqEngine.java
@@ -39,6 +39,7 @@ import org.eclipse.emf.compare.FeatureMapChange;
 import org.eclipse.emf.compare.Match;
 import org.eclipse.emf.compare.ReferenceChange;
 import org.eclipse.emf.compare.ResourceAttachmentChange;
+import org.eclipse.emf.compare.utils.EMFComparePredicates;
 import org.eclipse.emf.compare.utils.MatchUtil;
 import org.eclipse.emf.compare.utils.ReferenceUtil;
 import org.eclipse.emf.ecore.EObject;
@@ -167,8 +168,12 @@ public class DefaultReqEngine implements IReqEngine {
 						.getSource(), DifferenceKind.ADD));
 			}
 
-			difference.getRequires().addAll(requiredDifferences);
-			difference.getRequiredBy().addAll(requiredByDifferences);
+			difference.getRequires().addAll(
+					Collections2.filter(requiredDifferences, EMFComparePredicates.fromSide(difference
+							.getSource())));
+			difference.getRequiredBy().addAll(
+					Collections2.filter(requiredByDifferences, EMFComparePredicates.fromSide(difference
+							.getSource())));
 		}
 
 	}
@@ -302,7 +307,8 @@ public class DefaultReqEngine implements IReqEngine {
 			if (valueMatch != null) {
 				for (Diff candidate : filter(valueMatch.getDifferences(), or(
 						instanceOf(ReferenceChange.class), instanceOf(FeatureMapChange.class)))) {
-					if (candidate.getKind() == DifferenceKind.DELETE || isDeleteOrUnsetDiff(candidate)) {
+					if (candidate.getSource() == sourceDifference.getSource()
+							&& (candidate.getKind() == DifferenceKind.DELETE || isDeleteOrUnsetDiff(candidate))) {
 						result.add(candidate);
 					}
 				}
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/utils/EMFComparePredicates.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/utils/EMFComparePredicates.java
index 2cb60ad6d..91121c0e0 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/utils/EMFComparePredicates.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/utils/EMFComparePredicates.java
@@ -555,6 +555,24 @@ public final class EMFComparePredicates {
 	}
 
 	/**
+	 * This can be used to check that a given Diff originates from the given {@code source} side.
+	 * 
+	 * @param diff
+	 *            The diff the side of which will be used to filter.
+	 * @return The created predicate.
+	 */
+	public static Predicate<? super Diff> sameSideAs(final Diff diff) {
+		if (diff == null) {
+			throw new IllegalArgumentException();
+		}
+		return new Predicate<Diff>() {
+			public boolean apply(Diff input) {
+				return input != null && input.getSource() == diff.getSource();
+			}
+		};
+	}
+
+	/**
 	 * This can be used in order to check that a Diff has been detected on the given EObject.
 	 * 
 	 * @param eObject