[515819] Do not lose the cross referencer after DND to resource root

Sometimes the model element contents and cross references are modified
before the REMOVE notification. If an object is dropped as a new
resource root, it has no container after the move to
resource.getContents(), the eContainer() is null but the element is
still contained in a resource (which has the cross ref adapter) so it
should not be removed or we will a sub-tree of the model without the
semantic cross referencer.

Bug: 515819
Cherry-picked-from: 515684
Change-Id: Ieecc9f652abf7a692745ad4fa6af6b435d5b618b
Signed-off-by: Maxime Porhel <maxime.porhel@obeo.fr>

2 files changed, 83 insertions, 20 deletions

diff --git a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/util/LazyCrossReferencer.java b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/util/LazyCrossReferencer.java
index 516dbd17d4..23665544a6 100644
--- a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/util/LazyCrossReferencer.java
+++ b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/util/LazyCrossReferencer.java
@@ -21,7 +21,8 @@ import org.eclipse.emf.ecore.resource.Resource;
 import com.google.common.collect.Iterables;
 
 /**
- * A lazy cross referencer which does nothing until one of its method is called. <BR>
+ * A lazy cross referencer which does nothing until one of its method is called.
+ * <BR>
  * <BR>
  * This cross referencer also reacts to {@link EObject} removal from their
  * containing reference : it removes itself automatically from their adapters
@@ -192,7 +193,11 @@ public class LazyCrossReferencer extends ECrossReferenceAdapterWithUnproxyCapabi
 
     /**
      * This method does not remove the adapter from the notification old value
-     * if its new container is already set and also has the adapter.
+     * in two cases:
+     * <ul>
+     * <li>if its new container is already set and also has the adapter</li>
+     * <li>if the element is now a root of a resource which has the adapter</li>
+     * </ul>
      * 
      * @param notification
      *            a containment notification
@@ -203,7 +208,12 @@ public class LazyCrossReferencer extends ECrossReferenceAdapterWithUnproxyCapabi
         boolean toRemove = true;
 
         if (oldValue instanceof EObject) {
-            EObject currentContainer = ((EObject) oldValue).eContainer();
+            EObject removedEObject = (EObject) oldValue;
+
+            Notifier currentContainer = removedEObject.eContainer();
+            if (currentContainer == null) {
+                currentContainer = removedEObject.eResource();
+            }
 
             if (currentContainer != null && currentContainer != notification.getNotifier() && currentContainer.eAdapters().contains(this)) {
                 toRemove = false;
diff --git a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/SiriusCrossReferenceAdapterTests.java b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/SiriusCrossReferenceAdapterTests.java
index fd98b27099..331b1c2ea2 100644
--- a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/SiriusCrossReferenceAdapterTests.java
+++ b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/SiriusCrossReferenceAdapterTests.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2015 THALES GLOBAL SERVICES.
+ * Copyright (c) 2015, 2017 THALES GLOBAL SERVICES 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
@@ -16,8 +16,14 @@ import java.util.Iterator;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.emf.common.command.IdentityCommand;
 import org.eclipse.emf.common.notify.Adapter;
+import org.eclipse.emf.common.notify.Notification;
+import org.eclipse.emf.common.util.TreeIterator;
 import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.InternalEObject;
+import org.eclipse.emf.ecore.impl.ENotificationImpl;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.ecore.resource.ResourceSet;
 import org.eclipse.emf.transaction.RecordingCommand;
@@ -28,14 +34,14 @@ import org.eclipse.sirius.common.tools.api.util.LazyCrossReferencer;
 import org.eclipse.sirius.common.tools.api.util.SiriusCrossReferenceAdapter;
 import org.eclipse.sirius.tests.sample.component.Component;
 import org.eclipse.sirius.tests.sample.component.ComponentFactory;
+import org.eclipse.sirius.tests.sample.component.ComponentPackage;
 import org.eclipse.sirius.tests.support.api.SiriusTestCase;
 import org.eclipse.sirius.tools.api.command.ICommandFactory;
 import org.eclipse.sirius.viewpoint.DAnalysisSessionEObject;
 
 /**
- * Class containing tests to update of {@link SiriusCrossReferenceAdapter} after
- * CRUD action on resources through DAnalysisSessionImpl such
- * unload/reload/remove resource, close session.
+ * Class containing tests to update of {@link SiriusCrossReferenceAdapter} after CRUD action on resources through
+ * DAnalysisSessionImpl such unload/reload/remove resource, close session.
  * 
  * @author <a href="mailto:laurent.fasani@obeo.fr">Laurent Fasani</a>
  */
@@ -50,18 +56,19 @@ public class SiriusCrossReferenceAdapterTests extends SiriusTestCase {
         super.setUp();
         setWarningCatchActive(true);
 
+        // create session with empty aird
+        genericSetUp();
+
+        // add semantic resources
+        initSemanticResource();
     }
 
     /**
-     * Check that fragmented resource is not reloaded during its unload when it
-     * has been externally modified.
+     * Check that fragmented resource is not reloaded during its unload when it has been externally modified.
      * 
      * @throws Exception
      */
     public void testDisablingCrossReferencerWhileReloadingResource() throws Exception {
-        genericSetUp();
-
-        initSemanticResource();
 
         // check that semantic crossRefAdapter is set on fragmented resource
         Resource fragmentedResource = ((DAnalysisSessionEObject) session).getControlledResources().get(0);
@@ -93,19 +100,12 @@ public class SiriusCrossReferenceAdapterTests extends SiriusTestCase {
     }
 
     /**
-     * Check that fragmented resource is not reloaded during its unload when it
-     * has been externally deleted.
+     * Check that fragmented resource is not reloaded during its unload when it has been externally deleted.
      * 
      * @throws Exception
      */
     public void testDisablingCrossReferencerWhileDeletingResource() throws Exception {
 
-        // create session with empty aird
-        genericSetUp();
-
-        // add semantic resources
-        initSemanticResource();
-
         // simulation of DELETION of fragmentResource
         File fragFile = ResourcesPlugin.getWorkspace().getRoot().getProject(TEMPORARY_PROJECT_NAME).getFile(FRAGMENT_FILE_NAME).getLocation().toFile();
         fragFile.delete();
@@ -129,6 +129,59 @@ public class SiriusCrossReferenceAdapterTests extends SiriusTestCase {
     }
 
     /**
+     * Check that if that the session cross referencer is not removed if a REMOVE notification is handled after the add,
+     * ie the old value is already added to a resource with the same cross reference adapter.
+     * 
+     * @throws Exception
+     */
+    public void testNoAdapterRemovalAfterLateRemoveNotificationReception() throws Exception {
+        // Check the initial check.
+        checkCrossReferenceIsInstalledOnAllSemanticElements();
+
+        final Component compoRoot = (Component) session.getSemanticResources().iterator().next().getContents().get(0);
+        final Component compo1 = compoRoot.getChildren().get(0);
+        final Component compo2 = compo1.getChildren().get(0);
+
+        // DND compo2 as second root of the semantic resource
+        session.getTransactionalEditingDomain().getCommandStack().execute(new RecordingCommand(session.getTransactionalEditingDomain()) {
+
+            @Override
+            protected void doExecute() {
+                compo1.getChildren().remove(compo2);
+                session.getSemanticResources().iterator().next().getContents().add(compo2);
+            }
+        });
+
+        // Check the lazy cross referencer installation
+        checkCrossReferenceIsInstalledOnAllSemanticElements();
+
+        // Simulate the reception of a late reception of the REMOVE notification
+        session.getTransactionalEditingDomain().getCommandStack().execute(new IdentityCommand() {
+            @Override
+            public void execute() {
+                Notification removeNotification = new ENotificationImpl((InternalEObject) compo1, Notification.REMOVE, ComponentPackage.Literals.COMPONENT__CHILDREN, compo2, null);
+                compo1.eNotify(removeNotification);
+            }
+        });
+
+        // Check the lazy cross referencer installation
+        checkCrossReferenceIsInstalledOnAllSemanticElements();
+    }
+
+    private void checkCrossReferenceIsInstalledOnAllSemanticElements() {
+        for (Resource res : session.getSemanticResources()) {
+            assertTrue("The semantic cross referencer is not installed on the resource " + res.getURI(), res.eAdapters().contains(session.getSemanticCrossReferencer()));
+
+            TreeIterator<EObject> eAllContents = res.getAllContents();
+            while (eAllContents.hasNext()) {
+                EObject obj = eAllContents.next();
+                assertTrue("The semantic cross referencer is not installed on " + obj, obj.eAdapters().contains(session.getSemanticCrossReferencer()));
+            }
+
+        }
+    }
+
+    /**
      * Initialize semantic resources
      */
     private void initSemanticResource() {