[509970] Avoid to open a new Sirius session on GoTo marker

This commit fixes several problems:
1- SessionEditorInput: Only add a getExistingSession() in the
create(URI) method of SessionEditorInput is OK, if there is
no refresh that modifies the editor at opening. Tested with
o.e.s.t.swtbot.GoToMarkerTraceabilityWithUserInteractionTest.testTraceabilityWithNoOpenedRepresentationsWithoutRefreshAtOpening().
In other cases, there is an "IllegalStateException: Cannot activate
read/write transaction in read-only transaction context" because we try
to refresh the diagram (modify it) in the read transaction launched by
editingDomain.runExclusive() of
AbstractModelMarkerNavigationProvider.gotoMarker().
2- Copy of AbstractModelMarkerNavigationProvider: To avoid above problem
the GMF class AbstractModelMarkerNavigationProvider has been copied to
not launch the gotoMarker in runExclusive if the "refresh at opening" is
set to true. Tested with
o.e.s.t.swtbot.GoToMarkerTraceabilityWithUserInteractionTest.testTraceabilityWithNoOpenedRepresentationsWithRefreshAtOpening()
3- SessionEditorInput: If the session does not exist, we create it and
open it. It is then reused by the "real" editor. Tested with
o.e.s.t.swtbot.GoToMarkerTraceabilityWithUserInteractionTest.testTraceabilityWithClosedSession().
4- In SessionEditorInput, the status initialization has also been
changed (to avoid regressions detected by
DialectEditorsOpeningWithFailingSessionOpeningTests). The initialization
of the field can override a setting done indirectly by the super() that
calls getSession().

Bug: 509970
Change-Id: Ic26b562bf867621ad563e4a8f095e960518791ee
Signed-off-by: Laurent Redor <laurent.redor@obeo.fr>

4 files changed, 364 insertions, 39 deletions

diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/internal/providers/AbstractModelMarkerNavigationProvider.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/internal/providers/AbstractModelMarkerNavigationProvider.java
new file mode 100644
index 0000000000..406360da69
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/internal/providers/AbstractModelMarkerNavigationProvider.java
@@ -0,0 +1,220 @@
+/******************************************************************************
+ * Copyright (c) 2002, 2018 IBM Corporation 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    IBM Corporation - initial API and implementation 
+ ****************************************************************************/
+package org.eclipse.sirius.diagram.ui.internal.providers;
+
+import java.io.UnsupportedEncodingException;
+import java.net.URLDecoder;
+import java.util.Iterator;
+import java.util.List;
+
+import org.eclipse.core.resources.IMarker;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.common.util.WrappedException;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.emf.ecore.resource.ResourceSet;
+import org.eclipse.emf.edit.domain.EditingDomain;
+import org.eclipse.emf.edit.domain.IEditingDomainProvider;
+import org.eclipse.emf.transaction.TransactionalEditingDomain;
+import org.eclipse.gmf.runtime.common.core.util.Log;
+import org.eclipse.gmf.runtime.common.core.util.Trace;
+import org.eclipse.gmf.runtime.common.ui.services.marker.AbstractMarkerNavigationProvider;
+import org.eclipse.gmf.runtime.emf.ui.internal.MslUIDebugOptions;
+import org.eclipse.gmf.runtime.emf.ui.internal.MslUIPlugin;
+import org.eclipse.gmf.runtime.emf.ui.internal.MslUIStatusCodes;
+import org.eclipse.sirius.ui.business.api.dialect.DialectUIManager;
+import org.eclipse.ui.IEditorPart;
+
+/**
+ * Abstract Model Marker Navigation Provider this abstract class provides the necessary wrapping required to perform
+ * model operations related to the navigation of markers. If the marker attributes contain model element information
+ * that needs to be resolved, the corresponding marker provider should be derived from this class.
+ * <p>
+ * Derived classes should implement the getContext() and the doGotoMarker() methods. The latter method will be called
+ * within a model read operation.
+ * <p>
+ * Class copied from org.eclipse.gmf.runtime.emf.ui.providers.marker.AbstractModelMarkerNavigationProvider to not run
+ * the goto marker in exclusive if refresh at opening is set to true (as the refresh can make modification).
+ * 
+ * @author Kevin Cornell
+ */
+public abstract class AbstractModelMarkerNavigationProvider
+    extends AbstractMarkerNavigationProvider {
+
+    private TransactionalEditingDomain editingDomain;
+    
+    /**
+     * Perform the feedback for navigating to the given marker within a
+     * model read action.
+     */
+    @Override
+    public final void gotoMarker(
+        final IEditorPart editor,
+        final IMarker marker) {
+
+        // Must save the editor first since it will probably be used in 
+        // the logic to obtain the model operation context.
+        setEditor(editor);
+        
+        // Remember the editing domain associated with this editor
+        IEditingDomainProvider domainProvider = getEditor().getAdapter(IEditingDomainProvider.class);
+        
+        if (domainProvider != null) {
+            EditingDomain domain = domainProvider.getEditingDomain();
+            
+            if (domain instanceof TransactionalEditingDomain) {
+                editingDomain = (TransactionalEditingDomain) domain;
+            }
+        }
+        
+        // If the refresh at opening is activated, we do not run the gotoMarker
+        // in runExclusive since the refresh can modify the model. See bug
+        // 509970.
+        if (DialectUIManager.INSTANCE.isRefreshActivatedOnRepresentationOpening()) {
+            AbstractModelMarkerNavigationProvider.super.gotoMarker(editor, marker);
+        } else if (editingDomain != null) {
+            if (editingDomain != null) {
+    
+                // Perform the "goto" in a read operation.
+                try {
+                    editingDomain.runExclusive(new Runnable() {
+
+                        @Override
+                        public void run() {
+                            AbstractModelMarkerNavigationProvider.super.gotoMarker(editor, marker);
+                        }
+                    });
+
+                } catch (InterruptedException e) {
+                    Trace.catching(MslUIPlugin.getDefault(), MslUIDebugOptions.EXCEPTIONS_CATCHING, getClass(), "gotoMarker", e); //$NON-NLS-1$
+                    Log.error(MslUIPlugin.getDefault(), MslUIStatusCodes.IGNORED_EXCEPTION_WARNING, e.getLocalizedMessage(), e);
+                }
+            }
+        }
+    }
+    
+    /**
+     * Determines the EMF resource to which a marker is attached.
+     * 
+     * @param marker a marker
+     * @return the corresponding EMF resource, or <code>null</code> if either
+     *     the marker doesn't {@link IMarker#exists() exist} or its resource
+     *     cannot be loaded by EMF
+     */
+    protected Resource getResource(IMarker marker) {
+    	Resource result = null;
+    	
+    	if (marker.exists()) {
+    		// a non-existent marker cannot have a resource
+    		
+	        IPath resourcePath = marker.getResource().getLocation();
+	        
+	        if (resourcePath != null) {
+	        	// if the resource path is null, then I can't locate any objects
+	        	// referenced in this marker on that non-existent resource
+	        	 
+                ResourceSet resourceSet = editingDomain.getResourceSet();
+                URI uri = URI.createFileURI(resourcePath.toOSString());
+                result = resourceSet.getResource(uri, true);
+	        }
+    	}
+        
+        return result;
+    }
+    
+    /**
+     * Given a list of element IDs, looks up the elements, themselves, and
+     * returns them in the same order.
+     * <p>
+     * The <code>ids</code> passed to this method should follow a couple of
+     * conventions for compactness of implementation in a marker:
+     * <ul>
+     *   <li>any ID in the list that is a URI fragment (i.e., does not include
+     *       a resource URI) is assumed to be relative to the URI of the
+     *       specified <code>resource</code></li>
+     *   <li>any ID in the list that does not reference an object in the
+     *       specified <code>resource</code> must be a fully-qualified URI
+     *       (i.e., it must include a resource URI part)</li>
+     * </ul>
+     * Thus, in the majority of cases (where all referenced objects are in the
+     * resource that has the marker), the object IDs in the marker will be as
+     * compact as possible.
+     * </p>
+     * 
+     * 
+     * @param ids a list of element IDs, as described above
+     * @param resource the resource that has a marker from which the list of
+     *     IDs was extracted.  URI fragments in the <code>ids</code> list are
+     *     assumed to be relative to this resource's URI.  Must not be
+     *     <code>null</code>
+     * @return the corresponding list of {@link EObject}s, in the same order as
+     *     the <code>ids</code>, though not including any elements that could
+     *     not be located (due to stale IDs)
+     */
+    protected List getEObjects(List ids, Resource resource) {
+    	List result = new java.util.ArrayList(ids.size());
+    	
+    	URI resourceUri = resource.getURI();
+    	ResourceSet rset = resource.getResourceSet();
+    	
+    	if (rset != null) {
+    		// can't do anything if the resource is not in a resource set
+    		
+    		for (Iterator iter = ids.iterator(); iter.hasNext();) {
+    			String nextId = (String) iter.next();
+    			
+    			URI nextUri;
+    			
+    			int hashPos = nextId.indexOf('#');
+    			
+    			if (hashPos <= 0) {
+    				// the ID is a URI fragment.  Make sure not to omit the
+    				//   hash symbol in the fragment if there is one
+    				nextUri = resourceUri.appendFragment(
+    					nextId.substring(hashPos + 1));
+    			} else {
+    				// the URI is a fully-qualified one.  The Resource URI
+    				// portion will need to be decoded but the EObject fragment
+    				// portion will not, because it is decoded by MSL
+    				String resUriStr = nextId.substring(0, hashPos);
+    				String elemIdStr = nextId.substring(hashPos + 1);
+    				
+    				try {
+    					// use UTF-8 encoding for the URI, which is the
+    					//   standard encoding for XMI
+    					resUriStr = URLDecoder.decode(resUriStr, "UTF-8"); //$NON-NLS-1$
+    				} catch (UnsupportedEncodingException e) {
+    					// UTF-8 is always available in any Java platform
+    				}
+    				
+    				nextUri = URI.createURI(resUriStr).appendFragment(elemIdStr);
+    			}
+    			
+    			// load on demand because we need to select the element in an
+    			// open model in the UI
+    			try {
+    				EObject element = rset.getEObject(nextUri, true);
+    				
+    				if (element != null) {
+    					result.add(element);
+    				}
+    			} catch (WrappedException e) {
+    				// this is expected in the case of cross-reference URIs that
+    				// can no longer be resolved because of a bad resource
+    			}
+    		}
+    	}
+    	
+    	return result;
+    }
+
+}
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/internal/providers/SiriusMarkerNavigationProvider.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/internal/providers/SiriusMarkerNavigationProvider.java
index 946bbf1944..8790e7529e 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/internal/providers/SiriusMarkerNavigationProvider.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/internal/providers/SiriusMarkerNavigationProvider.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2015 THALES GLOBAL SERVICES and others.
+ * Copyright (c) 2007, 2018 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
@@ -22,7 +22,6 @@ import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.gef.EditPart;
 import org.eclipse.gmf.runtime.diagram.ui.parts.DiagramEditor;
-import org.eclipse.gmf.runtime.emf.ui.providers.marker.AbstractModelMarkerNavigationProvider;
 import org.eclipse.gmf.runtime.notation.Diagram;
 import org.eclipse.sirius.diagram.DiagramPlugin;
 import org.eclipse.sirius.diagram.ui.part.SiriusDiagramEditorUtil;
diff --git a/plugins/org.eclipse.sirius.tests.swtbot/src/org/eclipse/sirius/tests/swtbot/GoToMarkerTraceabilityWithUserInteractionTest.java b/plugins/org.eclipse.sirius.tests.swtbot/src/org/eclipse/sirius/tests/swtbot/GoToMarkerTraceabilityWithUserInteractionTest.java
index 9631ca88b7..4a0ea3f80d 100644
--- a/plugins/org.eclipse.sirius.tests.swtbot/src/org/eclipse/sirius/tests/swtbot/GoToMarkerTraceabilityWithUserInteractionTest.java
+++ b/plugins/org.eclipse.sirius.tests.swtbot/src/org/eclipse/sirius/tests/swtbot/GoToMarkerTraceabilityWithUserInteractionTest.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2010, 2017 THALES GLOBAL SERVICES.
+ * Copyright (c) 2010, 2018 THALES GLOBAL SERVICES.
  * 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
@@ -21,7 +21,9 @@ import org.eclipse.emf.ecore.EValidator;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.ecore.resource.ResourceSet;
 import org.eclipse.emf.ecore.util.EcoreUtil;
+import org.eclipse.emf.edit.command.RemoveCommand;
 import org.eclipse.emf.edit.domain.IEditingDomainProvider;
+import org.eclipse.emf.transaction.TransactionalEditingDomain;
 import org.eclipse.gmf.runtime.common.ui.util.WorkbenchPartDescriptor;
 import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
 import org.eclipse.gmf.runtime.diagram.ui.parts.IDiagramWorkbenchPart;
@@ -29,6 +31,8 @@ import org.eclipse.gmf.runtime.notation.View;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.ITreeSelection;
+import org.eclipse.sirius.business.api.session.Session;
+import org.eclipse.sirius.common.ui.tools.api.util.EclipseUIUtil;
 import org.eclipse.sirius.diagram.DDiagram;
 import org.eclipse.sirius.diagram.ui.part.SiriusDiagramEditor;
 import org.eclipse.sirius.diagram.ui.part.ValidateAction;
@@ -36,12 +40,15 @@ import org.eclipse.sirius.table.metamodel.table.DTable;
 import org.eclipse.sirius.tests.swtbot.support.api.business.UILocalSession;
 import org.eclipse.sirius.tests.swtbot.support.api.business.UIResource;
 import org.eclipse.sirius.tests.swtbot.support.api.condition.SessionClosedCondition;
+import org.eclipse.sirius.tests.swtbot.support.api.condition.SessionSavedCondition;
 import org.eclipse.sirius.tests.swtbot.support.api.editor.SWTBotSiriusDiagramEditor;
 import org.eclipse.sirius.tests.swtbot.support.utils.SWTBotUtils;
 import org.eclipse.sirius.ui.business.api.dialect.DialectEditor;
 import org.eclipse.sirius.ui.business.api.dialect.marker.TraceabilityMarkerNavigationProvider;
+import org.eclipse.sirius.ui.business.api.session.SessionEditorInput;
 import org.eclipse.sirius.ui.tools.internal.editor.AbstractDTreeEditor;
 import org.eclipse.sirius.viewpoint.DRepresentationElement;
+import org.eclipse.sirius.viewpoint.provider.Messages;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swtbot.eclipse.finder.widgets.SWTBotEditor;
@@ -52,6 +59,9 @@ import org.eclipse.swtbot.swt.finder.widgets.SWTBotTree;
 import org.eclipse.swtbot.swt.finder.widgets.SWTBotTreeItem;
 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.IEditorReference;
+import org.eclipse.ui.IPartListener2;
+import org.eclipse.ui.IWorkbenchPartReference;
+import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.ide.IGotoMarker;
 import org.junit.Assert;
@@ -97,6 +107,59 @@ public class GoToMarkerTraceabilityWithUserInteractionTest extends AbstractScena
     private UILocalSession localSession;
 
     /**
+     * A part listener to detect "Default Editor" activation and store the
+     * session of this editor to be compared after with the "real" editor.
+     */
+    private IPartListener2 defaultEditorPartListener = new IPartListener2() {
+        @Override
+        public void partActivated(IWorkbenchPartReference partRef) {
+            if (partRef instanceof IEditorReference && Messages.SessionEditorInput_defaultEditorName.equals(partRef.getTitle())) {
+                try {
+                    if (((IEditorReference) partRef).getEditorInput() instanceof SessionEditorInput) {
+                        sessionOfDummyEditor = ((SessionEditorInput) ((IEditorReference) partRef).getEditorInput()).getSession();
+                    }
+                } catch (PartInitException e) {
+                    // Do nothing
+                }
+            }
+        }
+
+        @Override
+        public void partVisible(IWorkbenchPartReference partRef) {
+        }
+
+        @Override
+        public void partOpened(IWorkbenchPartReference partRef) {
+        }
+
+        @Override
+        public void partInputChanged(IWorkbenchPartReference partRef) {
+        }
+
+        @Override
+        public void partHidden(IWorkbenchPartReference partRef) {
+        }
+
+        @Override
+        public void partDeactivated(IWorkbenchPartReference partRef) {
+        }
+
+        @Override
+        public void partClosed(IWorkbenchPartReference partRef) {
+        }
+
+        @Override
+        public void partBroughtToTop(IWorkbenchPartReference partRef) {
+        }
+    };
+
+    /**
+     * This variable is initialized when the above part listener is called and
+     * so when the dummy editor is activated.
+     */
+    private Session sessionOfDummyEditor;
+
+    /**
      * The icon in the outline displayed when labels are shown (not hidden).
      */
     protected Image shownImage;
@@ -124,6 +187,8 @@ public class GoToMarkerTraceabilityWithUserInteractionTest extends AbstractScena
         if (traceMarker != null) {
             traceMarker.delete();
         }
+        sessionOfDummyEditor = null;
+        defaultEditorPartListener = null;
     }
 
     /**
@@ -176,10 +241,22 @@ public class GoToMarkerTraceabilityWithUserInteractionTest extends AbstractScena
     }
 
     /**
-     * Ensure that after closing a representation editor having validation
-     * errors, it can be reopened using an error marker from the Problem view.
+     * Ensure that after closing a representation editor (with refresh at
+     * opening) having validation errors, it can be reopened using an error
+     * marker from the Problem view.
+     */
+    public void testTraceabilityWithNoOpenedRepresentationsWithRefreshAtOpening() {
+        changeSiriusUIPreference(org.eclipse.sirius.ui.business.api.preferences.SiriusUIPreferencesKeys.PREF_REFRESH_ON_REPRESENTATION_OPENING.name(), true);
+        processEditorOpeningFromMarker(false);
+    }
+
+    /**
+     * Ensure that after closing a representation editor (without refresh at
+     * opening) having validation errors, it can be reopened using an error
+     * marker from the Problem view.
      */
-    public void testTraceabilityWithNoOpenedRepresentations() {
+    public void testTraceabilityWithNoOpenedRepresentationsWithoutRefreshAtOpening() {
+        changeSiriusUIPreference(org.eclipse.sirius.ui.business.api.preferences.SiriusUIPreferencesKeys.PREF_REFRESH_ON_REPRESENTATION_OPENING.name(), false);
         processEditorOpeningFromMarker(false);
     }
 
@@ -205,6 +282,15 @@ public class GoToMarkerTraceabilityWithUserInteractionTest extends AbstractScena
         editor.close();
         SWTBotUtils.waitAllUiEvents();
 
+        // Make a semantic change that implies a change at the next
+        // diagram refresh (at opening in this case)
+        TransactionalEditingDomain ted = localSession.getOpenedSession().getTransactionalEditingDomain();
+        URI uri = URI.createURI("platform:/resource/DesignerTestProject/vp1038.ecore#//p3");
+        semanticElementForTraceability = ted.getResourceSet().getEObject(uri, true);
+        ted.getCommandStack().execute(RemoveCommand.create(ted, semanticElementForTraceability));
+        localSession.getOpenedSession().save(new NullProgressMonitor());
+        bot.waitUntil(new SessionSavedCondition(localSession.getOpenedSession()));
+
         if (fromClosedSession) {
             // Close session
             SessionClosedCondition sessionClosedCondition = new SessionClosedCondition(localSession.getOpenedSession());
@@ -217,15 +303,26 @@ public class GoToMarkerTraceabilityWithUserInteractionTest extends AbstractScena
         problemsView.setFocus();
         SWTBotTree problemsTree = problemsView.bot().tree();
         problemsTree.getTreeItem("Errors (3 items)").expand();
-
-        // Reopen the editor using a marker created during the validation
         final SWTBotTreeItem node = problemsTree.getTreeItem("Errors (3 items)").getNode("The namespace URI '' is not well formed");
         node.select();
 
-        // Double click the error marker to reopen the diagram
         Assert.assertFalse("An error happened before opening an editor using an error marker: " + getErrorLoggersMessage(), doesAnErrorOccurs());
-        node.doubleClick();
-        Assert.assertFalse("An error happened on opening of an editor using an error marker: " + getErrorLoggersMessage(), doesAnErrorOccurs());
+        // Add a listener to detect the dummy editor opened after the goto
+        // marker
+        EclipseUIUtil.getActivePage().addPartListener(defaultEditorPartListener);
+        try {
+            // Double click the error marker to reopen the diagram
+            node.doubleClick();
+            Assert.assertFalse("An error happened on opening of an editor using an error marker: " + getErrorLoggersMessage(), doesAnErrorOccurs());
+            IEditorPart currentEditor = EclipseUIUtil.getActiveEditor();
+            assertTrue("The current editor, opened through a GoTo marker must have a SessionEditorInput as editor input", currentEditor.getEditorInput() instanceof SessionEditorInput);
+            if (sessionOfDummyEditor != null) {
+                assertEquals("The session of the editor, opened through a GoTo marker, must be the same as the dummy editor, temporarly opened to correctly resolve the GoTo marker.",
+                        sessionOfDummyEditor, ((SessionEditorInput) currentEditor.getEditorInput()).getSession());
+            }
+        } finally {
+            EclipseUIUtil.getActivePage().removePartListener(defaultEditorPartListener);
+        }
     }
 
     /**
@@ -258,10 +355,10 @@ public class GoToMarkerTraceabilityWithUserInteractionTest extends AbstractScena
     public void testTraceabilityWhenGoToMarkerIsCalledOnAllOpenedEditors() {
         setUpMarker(REPRESENTATION_EMPTY_DIAGRAM, "emptyDiagram", "platform:/resource/DesignerTestProject/vp1038.ecore#//p1/A");
 
-        final SWTBotSiriusDiagramEditor emptyDiagramEditor2 = (SWTBotSiriusDiagramEditor) openRepresentation(localSession.getOpenedSession(), REPRESENTATION_EMPTY_DIAGRAM, "emptyDiagram2",
+        openRepresentation(localSession.getOpenedSession(), REPRESENTATION_EMPTY_DIAGRAM, "emptyDiagram2",
                 DDiagram.class);
 
-        final SWTBotSiriusDiagramEditor emptyDiagramEditor3 = (SWTBotSiriusDiagramEditor) openRepresentation(localSession.getOpenedSession(), REPRESENTATION_EMPTY_DIAGRAM, "emptyDiagram3",
+        openRepresentation(localSession.getOpenedSession(), REPRESENTATION_EMPTY_DIAGRAM, "emptyDiagram3",
                 DDiagram.class);
 
         callGoToMarkerOnAllOpenedEditors(traceMarker);
@@ -332,6 +429,7 @@ public class GoToMarkerTraceabilityWithUserInteractionTest extends AbstractScena
      * 
      * @return a shadow marker simulating Traceability behavior
      * @throws CoreException
+     *             In case of marker problem
      */
     protected IMarker createShadowTraceabilityMarker() throws CoreException {
 
diff --git a/plugins/org.eclipse.sirius.ui/src/org/eclipse/sirius/ui/business/api/session/SessionEditorInput.java b/plugins/org.eclipse.sirius.ui/src/org/eclipse/sirius/ui/business/api/session/SessionEditorInput.java
index 86fd85b7ec..e662703f5e 100644
--- a/plugins/org.eclipse.sirius.ui/src/org/eclipse/sirius/ui/business/api/session/SessionEditorInput.java
+++ b/plugins/org.eclipse.sirius.ui/src/org/eclipse/sirius/ui/business/api/session/SessionEditorInput.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2017 THALES GLOBAL SERVICES and others.
+ * Copyright (c) 2007, 2018 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
@@ -13,7 +13,6 @@ package org.eclipse.sirius.ui.business.api.session;
 import java.lang.ref.WeakReference;
 
 import org.eclipse.core.resources.IFile;
-import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.OperationCanceledException;
@@ -26,7 +25,6 @@ import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.sirius.business.api.session.Session;
 import org.eclipse.sirius.business.api.session.SessionManager;
-import org.eclipse.sirius.business.api.session.factory.SessionFactory;
 import org.eclipse.sirius.viewpoint.DRepresentation;
 import org.eclipse.sirius.viewpoint.DRepresentationDescriptor;
 import org.eclipse.sirius.viewpoint.provider.Messages;
@@ -59,7 +57,7 @@ public class SessionEditorInput extends URIEditorInput {
 
     private WeakReference<EObject> inputRef;
 
-    private IStatus status = Status.OK_STATUS;
+    private IStatus status;
 
     private URI repDescURI;
 
@@ -261,23 +259,8 @@ public class SessionEditorInput extends URIEditorInput {
             // previously closed session.
             if (sessionFromURI == null && restore) {
                 status = Status.OK_STATUS;
-                sessionFromURI = SessionManager.INSTANCE.openSession(sessionModelURI, new NullProgressMonitor(), SiriusEditPlugin.getPlugin().getUiCallback());
-            }
-
-            if (sessionFromURI != null && sessionFromURI.isOpen()) {
-                // The SessionUIManager creates and open an IEditingSession when
-                // a session is added to the SessionManager. This
-                // IEditingSession is closed and removed from the ui manager
-                // when the corresponding session is removed from the session
-                // manager (closed).
-                IEditingSession uiSession = SessionUIManager.INSTANCE.getUISession(sessionFromURI);
-                if (uiSession == null && restore) {
-                    uiSession = SessionUIManager.INSTANCE.getOrCreateUISession(sessionFromURI);
-                }
-                if (uiSession != null && !uiSession.isOpen()) {
-                    uiSession.open();
-                }
             }
+            sessionFromURI = openSession(sessionModelURI, restore, sessionFromURI);
         } catch (OperationCanceledException e) {
             sessionFromURI = null;
             status = new Status(IStatus.CANCEL, SiriusEditPlugin.ID, e.getLocalizedMessage(), e); // $NON-NLS-1$
@@ -294,6 +277,29 @@ public class SessionEditorInput extends URIEditorInput {
         return sessionFromURI;
     }
 
+    private static Session openSession(URI sessionModelURI, boolean restore, Session sessionFromURI) {
+        Session session = sessionFromURI;
+        if (session == null && restore) {
+            session = SessionManager.INSTANCE.openSession(sessionModelURI, new NullProgressMonitor(), SiriusEditPlugin.getPlugin().getUiCallback());
+        }
+
+        if (session != null && session.isOpen()) {
+            // The SessionUIManager creates and open an IEditingSession when
+            // a session is added to the SessionManager. This
+            // IEditingSession is closed and removed from the ui manager
+            // when the corresponding session is removed from the session
+            // manager (closed).
+            IEditingSession uiSession = SessionUIManager.INSTANCE.getUISession(session);
+            if (uiSession == null && restore) {
+                uiSession = SessionUIManager.INSTANCE.getOrCreateUISession(session);
+            }
+            if (uiSession != null && !uiSession.isOpen()) {
+                uiSession.open();
+            }
+        }
+        return session;
+    }
+
     @Override
     protected String getBundleSymbolicName() {
         return SiriusEditPlugin.getPlugin().getSymbolicName();
@@ -314,11 +320,10 @@ public class SessionEditorInput extends URIEditorInput {
      * @since 0.9.0
      */
     public static SessionEditorInput create(final URI sessionResourceURI) {
-        Session session;
-        try {
-            session = SessionFactory.INSTANCE.createSession(sessionResourceURI, new NullProgressMonitor());
-        } catch (CoreException e) {
-            return null;
+        // Use the existing session if there is one
+        Session session = SessionManager.INSTANCE.getExistingSession(sessionResourceURI);
+        if (session == null) {
+            session = SessionEditorInput.openSession(sessionResourceURI, true, null);
         }
         return new SessionEditorInput(sessionResourceURI, Messages.SessionEditorInput_defaultEditorName, session);
     }
@@ -389,6 +394,9 @@ public class SessionEditorInput extends URIEditorInput {
      * @return the status of the session opening, null is never returned
      */
     public IStatus getStatus() {
+        if (status == null) {
+            status = Status.OK_STATUS;
+        }
         return status;
     }
 
@@ -421,7 +429,7 @@ public class SessionEditorInput extends URIEditorInput {
         if (equals && o instanceof SessionEditorInput) {
             SessionEditorInput otherSessionEditorInput = (SessionEditorInput) o;
             IStatus otherStatus = otherSessionEditorInput.getStatus();
-            if (status != otherStatus) {
+            if (getStatus() != otherStatus) {
                 equals = false;
             } else {
                 EObject input = getInput(false);