Bug 468207: [StateMachine Diagram] cannot delete elements

https://bugs.eclipse.org/bugs/show_bug.cgi?id=468207

When a state machine has only one region, that region's zone annotation
is the empty string.  When that region has a stereotype applied (as
it does in Papyrus-RT real-time state machines), then the region has
a stereotype-comment compartment.  In that case, deletion of the
region view fails with a SIOOBE on attempt to take a substring of the
empty zone annotation value.

9 files changed, 205 insertions, 19 deletions

diff --git a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine/custom-src/org/eclipse/papyrus/uml/diagram/statemachine/custom/helpers/Zone.java b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine/custom-src/org/eclipse/papyrus/uml/diagram/statemachine/custom/helpers/Zone.java
index 1f17b3f2227..4e5b8d737ef 100644
--- a/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine/custom-src/org/eclipse/papyrus/uml/diagram/statemachine/custom/helpers/Zone.java
+++ b/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine/custom-src/org/eclipse/papyrus/uml/diagram/statemachine/custom/helpers/Zone.java
@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2014 CEA LIST.
+ * Copyright (c) 2014, 2016 CEA LIST, Christian W. Damus, and others.
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -8,6 +8,7 @@
  *
  * Contributors:
  *  CEA LIST - Initial API and implementation
+ *  Christian W. Damus - bug 468207
  */
 package org.eclipse.papyrus.uml.diagram.statemachine.custom.helpers;
 
@@ -28,6 +29,8 @@ import org.eclipse.papyrus.uml.diagram.statemachine.edit.parts.RegionEditPart;
 import org.eclipse.papyrus.uml.diagram.statemachine.edit.parts.StateMachineEditPart;
 import org.eclipse.papyrus.uml.diagram.statemachine.part.UMLVisualIDRegistry;
 
+import com.google.common.base.Strings;
+
 /**
  * Helper class used to manage the encoding of a region position within a state
  * machine or a state.
@@ -567,18 +570,20 @@ public class Zone {
 	 * @return the counterpart zone
 	 */
 	private static String getZoneCounterpart(String s) {
-		String cs = s.substring(0, s.length() - 1);
-		if (Zone.isRight(s)) {
-			return Zone.setLeft(cs);
-		}
-		if (Zone.isLeft(s)) {
-			return Zone.setRight(cs);
-		}
-		if (Zone.isBottom(s)) {
-			return Zone.setTop(cs);
-		}
-		if (Zone.isTop(s)) {
-			return Zone.setBottom(cs);
+		if (!Strings.isNullOrEmpty(s)) {
+			String cs = s.substring(0, s.length() - 1);
+			if (Zone.isRight(s)) {
+				return Zone.setLeft(cs);
+			}
+			if (Zone.isLeft(s)) {
+				return Zone.setRight(cs);
+			}
+			if (Zone.isBottom(s)) {
+				return Zone.setTop(cs);
+			}
+			if (Zone.isTop(s)) {
+				return Zone.setBottom(cs);
+			}
 		}
 		return s;
 	}
@@ -806,7 +811,7 @@ public class Zone {
 		// get the region zone
 		String zone = getZone(region);
 		// get its counterpart
-		if (zone == null) {
+		if (Strings.isNullOrEmpty(zone)) {
 			return;
 		}
 		String cZone = getZoneCounterpart(zone);
diff --git a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/META-INF/MANIFEST.MF b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/META-INF/MANIFEST.MF
index d4f6240dbb6..2f51a76fd63 100644
--- a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/META-INF/MANIFEST.MF
+++ b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/META-INF/MANIFEST.MF
@@ -20,9 +20,9 @@ Require-Bundle: org.eclipse.ui,
  org.eclipse.papyrus.infra.core.sasheditor;bundle-version="1.1.4",

  org.junit;bundle-version="4.10.0",

  org.eclipse.papyrus.junit.framework;bundle-version="1.1.4",

- org.eclipse.gmf.tooling.runtime;bundle-version="[3.3.0,

- 4.0.0)",

- org.eclipse.papyrus.junit.utils;bundle-version="1.1.4"

+ org.eclipse.gmf.tooling.runtime;bundle-version="[3.3.0,4.0.0)",

+ org.eclipse.papyrus.junit.utils;bundle-version="1.1.4",

+ org.eclipse.papyrus.infra.services.edit;bundle-version="1.1.4"

 Bundle-ActivationPolicy: lazy

 Bundle-ManifestVersion: 2

 Bundle-Activator: org.eclipse.papyrus.uml.diagram.statemachine.tests.Activator

diff --git a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/build.properties b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/build.properties
index 1b08f841b5e..c672072f1a8 100644
--- a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/build.properties
+++ b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/build.properties
@@ -3,5 +3,6 @@ output.. = bin/
 bin.includes = META-INF/,\

                .,\

                about.html,\

-               plugin.properties

+               plugin.properties,\

+               resources/

 src.includes = about.html

diff --git a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.di b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.di
new file mode 100644
index 00000000000..bf9abab340f
--- /dev/null
+++ b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.di
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xmi:XMI xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI"/>
diff --git a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.notation b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.notation
new file mode 100644
index 00000000000..e14e655d55b
--- /dev/null
+++ b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.notation
@@ -0,0 +1,57 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<notation:Diagram xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ecore="http://www.eclipse.org/emf/2002/Ecore" xmlns:notation="http://www.eclipse.org/gmf/runtime/1.0.2/notation" xmlns:style="http://www.eclipse.org/papyrus/infra/viewpoints/policy/style" xmlns:uml="http://www.eclipse.org/uml2/5.0.0/UML" xmi:id="_e2dM8PgUEeW8Us5SRbfNZA" type="PapyrusUMLStateMachineDiagram" name="SmDiagram" measurementUnit="Pixel">
+  <children xmi:type="notation:Shape" xmi:id="_e2dM8fgUEeW8Us5SRbfNZA" type="2000">
+    <children xmi:type="notation:DecorationNode" xmi:id="_e2dM8vgUEeW8Us5SRbfNZA" type="2001">
+      <layoutConstraint xmi:type="notation:Bounds" xmi:id="_e2dM8_gUEeW8Us5SRbfNZA" width="700" height="16"/>
+    </children>
+    <children xmi:type="notation:BasicCompartment" xmi:id="_e2dM9PgUEeW8Us5SRbfNZA" type="2002">
+      <children xmi:type="notation:Shape" xmi:id="_e2dM9fgUEeW8Us5SRbfNZA" type="3000">
+        <eAnnotations xmi:type="ecore:EAnnotation" xmi:id="_e2dM9vgUEeW8Us5SRbfNZA" source="RegionAnnotationKey">
+          <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_e2dM9_gUEeW8Us5SRbfNZA" key="RegionZoneKey" value=""/>
+        </eAnnotations>
+        <children xmi:type="notation:BasicCompartment" xmi:id="_e2dM-PgUEeW8Us5SRbfNZA" type="3002">
+          <children xmi:type="notation:Shape" xmi:id="_uy1CsPgXEeW8Us5SRbfNZA" type="8000">
+            <children xmi:type="notation:DecorationNode" xmi:id="_uy1CsvgXEeW8Us5SRbfNZA" type="8001">
+              <layoutConstraint xmi:type="notation:Location" xmi:id="_uy1Cs_gXEeW8Us5SRbfNZA" x="25" y="3"/>
+            </children>
+            <children xmi:type="notation:DecorationNode" xmi:id="_uy1CtPgXEeW8Us5SRbfNZA" type="8002">
+              <layoutConstraint xmi:type="notation:Location" xmi:id="_uy1CtfgXEeW8Us5SRbfNZA" x="25" y="-10"/>
+            </children>
+            <element xmi:type="uml:Pseudostate" href="model.uml#_uywKMPgXEeW8Us5SRbfNZA"/>
+            <layoutConstraint xmi:type="notation:Bounds" xmi:id="_uy1CsfgXEeW8Us5SRbfNZA" x="60" y="45"/>
+          </children>
+          <layoutConstraint xmi:type="notation:Bounds" xmi:id="_e2dM-fgUEeW8Us5SRbfNZA"/>
+        </children>
+        <element xmi:type="uml:Region" href="model.uml#_e2cl4PgUEeW8Us5SRbfNZA"/>
+        <layoutConstraint xmi:type="notation:Bounds" xmi:id="_e2dM-vgUEeW8Us5SRbfNZA" width="700" height="287"/>
+      </children>
+      <children xmi:type="notation:Shape" xmi:id="_uCACsPgXEeW8Us5SRbfNZA" type="StereotypeComment">
+        <styles xmi:type="notation:TitleStyle" xmi:id="_uCACsfgXEeW8Us5SRbfNZA" showTitle="true"/>
+        <styles xmi:type="notation:EObjectValueStyle" xmi:id="_uCACs_gXEeW8Us5SRbfNZA" name="BASE_ELEMENT">
+          <eObjectValue xmi:type="uml:Region" href="model.uml#_e2cl4PgUEeW8Us5SRbfNZA"/>
+        </styles>
+        <element xsi:nil="true"/>
+        <layoutConstraint xmi:type="notation:Bounds" xmi:id="_uCACsvgXEeW8Us5SRbfNZA" x="200"/>
+      </children>
+      <layoutConstraint xmi:type="notation:Bounds" xmi:id="_e2dM-_gUEeW8Us5SRbfNZA" y="16" width="700" height="287"/>
+    </children>
+    <element xmi:type="uml:StateMachine" href="model.uml#_ejtQEPgUEeW8Us5SRbfNZA"/>
+    <layoutConstraint xmi:type="notation:Bounds" xmi:id="_e2dM_PgUEeW8Us5SRbfNZA" x="30" y="30" width="700" height="303"/>
+  </children>
+  <styles xmi:type="notation:StringValueStyle" xmi:id="_e2dM_fgUEeW8Us5SRbfNZA" name="diagram_compatibility_version" stringValue="1.1.0"/>
+  <styles xmi:type="notation:DiagramStyle" xmi:id="_e2dM_vgUEeW8Us5SRbfNZA"/>
+  <styles xmi:type="style:PapyrusViewStyle" xmi:id="_e2dM__gUEeW8Us5SRbfNZA">
+    <owner xmi:type="uml:Class" href="model.uml#_djwO8PgUEeW8Us5SRbfNZA"/>
+  </styles>
+  <element xmi:type="uml:StateMachine" href="model.uml#_ejtQEPgUEeW8Us5SRbfNZA"/>
+  <edges xmi:type="notation:Connector" xmi:id="_uCACtPgXEeW8Us5SRbfNZA" type="StereotypeCommentLink" source="_e2dM9fgUEeW8Us5SRbfNZA" target="_uCACsPgXEeW8Us5SRbfNZA">
+    <styles xmi:type="notation:FontStyle" xmi:id="_uCACtfgXEeW8Us5SRbfNZA"/>
+    <styles xmi:type="notation:EObjectValueStyle" xmi:id="_uCACufgXEeW8Us5SRbfNZA" name="BASE_ELEMENT">
+      <eObjectValue xmi:type="uml:Region" href="model.uml#_e2cl4PgUEeW8Us5SRbfNZA"/>
+    </styles>
+    <element xsi:nil="true"/>
+    <bendpoints xmi:type="notation:RelativeBendpoints" xmi:id="_uCACtvgXEeW8Us5SRbfNZA" points="[0, 0, 0, 0]$[0, 0, 0, 0]"/>
+    <sourceAnchor xmi:type="notation:IdentityAnchor" xmi:id="_uCACt_gXEeW8Us5SRbfNZA"/>
+    <targetAnchor xmi:type="notation:IdentityAnchor" xmi:id="_uCACuPgXEeW8Us5SRbfNZA"/>
+  </edges>
+</notation:Diagram>
diff --git a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.uml b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.uml
new file mode 100644
index 00000000000..86492b1ac59
--- /dev/null
+++ b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/model.uml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xmi:XMI xmi:version="20131001" xmlns:xmi="http://www.omg.org/spec/XMI/20131001" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ecore="http://www.eclipse.org/emf/2002/Ecore" xmlns:states="http:///schemas/states/_pBeIEPgXEeW8Us5SRbfNZA/0" xmlns:uml="http://www.eclipse.org/uml2/5.0.0/UML" xsi:schemaLocation="http:///schemas/states/_pBeIEPgXEeW8Us5SRbfNZA/0 states.profile.uml#_pBhLYfgXEeW8Us5SRbfNZA">
+  <uml:Model xmi:id="_bgcTYPgUEeW8Us5SRbfNZA" name="model">
+    <packagedElement xmi:type="uml:Class" xmi:id="_djwO8PgUEeW8Us5SRbfNZA" name="Class1" classifierBehavior="_ejtQEPgUEeW8Us5SRbfNZA">
+      <ownedBehavior xmi:type="uml:StateMachine" xmi:id="_ejtQEPgUEeW8Us5SRbfNZA" name="StateMachine1">
+        <region xmi:type="uml:Region" xmi:id="_e2cl4PgUEeW8Us5SRbfNZA" name="Region1">
+          <subvertex xmi:type="uml:Pseudostate" xmi:id="_uywKMPgXEeW8Us5SRbfNZA" name="Initial1"/>
+        </region>
+      </ownedBehavior>
+    </packagedElement>
+    <profileApplication xmi:type="uml:ProfileApplication" xmi:id="_sQXtAPgXEeW8Us5SRbfNZA">
+      <eAnnotations xmi:type="ecore:EAnnotation" xmi:id="_sQYUEfgXEeW8Us5SRbfNZA" source="PapyrusVersion">
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_sQYUEvgXEeW8Us5SRbfNZA" key="Version" value="0.0.1"/>
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_sQYUE_gXEeW8Us5SRbfNZA" key="Comment" value=""/>
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_sQYUFPgXEeW8Us5SRbfNZA" key="Copyright" value=""/>
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_sQYUFfgXEeW8Us5SRbfNZA" key="Date" value="2016-04-01"/>
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_sQYUFvgXEeW8Us5SRbfNZA" key="Author" value=""/>
+      </eAnnotations>
+      <eAnnotations xmi:type="ecore:EAnnotation" xmi:id="_sQYUEPgXEeW8Us5SRbfNZA" source="http://www.eclipse.org/uml2/2.0.0/UML">
+        <references xmi:type="ecore:EPackage" href="states.profile.uml#_pBhLYfgXEeW8Us5SRbfNZA"/>
+      </eAnnotations>
+      <appliedProfile xmi:type="uml:Profile" href="states.profile.uml#_f3edsPgXEeW8Us5SRbfNZA"/>
+    </profileApplication>
+  </uml:Model>
+  <states:S1 xmi:id="_uBtu0PgXEeW8Us5SRbfNZA" base_Region="_e2cl4PgUEeW8Us5SRbfNZA"/>
+</xmi:XMI>
diff --git a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/states.profile.uml b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/states.profile.uml
new file mode 100644
index 00000000000..e669235e136
--- /dev/null
+++ b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/resources/bug468207/states.profile.uml
@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<uml:Profile xmi:version="20131001" xmlns:xmi="http://www.omg.org/spec/XMI/20131001" xmlns:ecore="http://www.eclipse.org/emf/2002/Ecore" xmlns:uml="http://www.eclipse.org/uml2/5.0.0/UML" xmi:id="_f3edsPgXEeW8Us5SRbfNZA" name="states" metaclassReference="_lA5OkPgXEeW8Us5SRbfNZA">
+  <eAnnotations xmi:type="ecore:EAnnotation" xmi:id="_pBhLYPgXEeW8Us5SRbfNZA" source="http://www.eclipse.org/uml2/2.0.0/UML">
+    <contents xmi:type="ecore:EPackage" xmi:id="_pBhLYfgXEeW8Us5SRbfNZA" name="states" nsURI="http:///schemas/states/_pBeIEPgXEeW8Us5SRbfNZA/0" nsPrefix="states">
+      <eAnnotations xmi:type="ecore:EAnnotation" xmi:id="_pBiZgfgXEeW8Us5SRbfNZA" source="PapyrusVersion">
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_pBiZgvgXEeW8Us5SRbfNZA" key="Version" value="0.0.1"/>
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_pBiZg_gXEeW8Us5SRbfNZA" key="Comment" value=""/>
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_pBiZhPgXEeW8Us5SRbfNZA" key="Copyright" value=""/>
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_pBiZhfgXEeW8Us5SRbfNZA" key="Date" value="2016-04-01"/>
+        <details xmi:type="ecore:EStringToStringMapEntry" xmi:id="_pBiZhvgXEeW8Us5SRbfNZA" key="Author" value=""/>
+      </eAnnotations>
+      <eClassifiers xmi:type="ecore:EClass" xmi:id="_pBhLYvgXEeW8Us5SRbfNZA" name="S1">
+        <eAnnotations xmi:type="ecore:EAnnotation" xmi:id="_pBhLY_gXEeW8Us5SRbfNZA" source="http://www.eclipse.org/uml2/2.0.0/UML" references="_lsLAMPgXEeW8Us5SRbfNZA"/>
+        <eStructuralFeatures xmi:type="ecore:EReference" xmi:id="_pBhLZPgXEeW8Us5SRbfNZA" name="base_Region" ordered="false" lowerBound="1">
+          <eType xmi:type="ecore:EClass" href="http://www.eclipse.org/uml2/5.0.0/UML#//Region"/>
+        </eStructuralFeatures>
+      </eClassifiers>
+    </contents>
+  </eAnnotations>
+  <elementImport xmi:type="uml:ElementImport" xmi:id="_lA5OkPgXEeW8Us5SRbfNZA" alias="Region">
+    <importedElement xmi:type="uml:Class" href="pathmap://UML_METAMODELS/UML.metamodel.uml#Region"/>
+  </elementImport>
+  <packagedElement xmi:type="uml:Stereotype" xmi:id="_lsLAMPgXEeW8Us5SRbfNZA" name="S1">
+    <ownedAttribute xmi:type="uml:Property" xmi:id="_nPZGcPgXEeW8Us5SRbfNZA" name="base_Region" association="_nPWqMPgXEeW8Us5SRbfNZA">
+      <type xmi:type="uml:Class" href="pathmap://UML_METAMODELS/UML.metamodel.uml#Region"/>
+    </ownedAttribute>
+  </packagedElement>
+  <packagedElement xmi:type="uml:Extension" xmi:id="_nPWqMPgXEeW8Us5SRbfNZA" name="E_S1_Region1" memberEnd="_nPYfYPgXEeW8Us5SRbfNZA _nPZGcPgXEeW8Us5SRbfNZA">
+    <ownedEnd xmi:type="uml:ExtensionEnd" xmi:id="_nPYfYPgXEeW8Us5SRbfNZA" name="extension_S1" type="_lsLAMPgXEeW8Us5SRbfNZA" aggregation="composite" association="_nPWqMPgXEeW8Us5SRbfNZA"/>
+  </packagedElement>
+</uml:Profile>
diff --git a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/src/org/eclipse/papyrus/uml/diagram/statemachine/custom/helpers/tests/ZoneTest.java b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/src/org/eclipse/papyrus/uml/diagram/statemachine/custom/helpers/tests/ZoneTest.java
new file mode 100644
index 00000000000..de974c094bc
--- /dev/null
+++ b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/src/org/eclipse/papyrus/uml/diagram/statemachine/custom/helpers/tests/ZoneTest.java
@@ -0,0 +1,61 @@
+/*****************************************************************************
+ * Copyright (c) 2016 Christian W. Damus 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:
+ *   Christian W. Damus - Initial API and implementation
+ *   
+ *****************************************************************************/
+
+package org.eclipse.papyrus.uml.diagram.statemachine.custom.helpers.tests;
+
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.junit.Assert.assertThat;
+
+import org.eclipse.gmf.runtime.common.core.command.ICommand;
+import org.eclipse.gmf.runtime.emf.type.core.requests.DestroyElementRequest;
+import org.eclipse.gmf.runtime.notation.Diagram;
+import org.eclipse.papyrus.infra.services.edit.service.ElementEditServiceUtils;
+import org.eclipse.papyrus.junit.framework.classification.tests.AbstractPapyrusTest;
+import org.eclipse.papyrus.junit.utils.rules.ActiveDiagram;
+import org.eclipse.papyrus.junit.utils.rules.PapyrusEditorFixture;
+import org.eclipse.papyrus.junit.utils.rules.PluginResource;
+import org.eclipse.papyrus.uml.diagram.statemachine.custom.helpers.Zone;
+import org.eclipse.uml2.uml.Behavior;
+import org.eclipse.uml2.uml.BehavioredClassifier;
+import org.junit.Rule;
+import org.junit.Test;
+
+/**
+ * Regression tests for the {@link Zone} utility class.
+ */
+public class ZoneTest extends AbstractPapyrusTest {
+	@Rule
+	public final PapyrusEditorFixture editor = new PapyrusEditorFixture();
+
+	/**
+	 * Verifies that no exception occurs to block the deletion of a diagram
+	 * that has a region with an empty zone annotation, as occurs in
+	 * Papyrus-RT real-time state machine diagrams.
+	 */
+	@Test
+	@PluginResource("resources/bug468207/model.di")
+	@ActiveDiagram("SmDiagram")
+	public void deleteDiagramWithEmptyZoneAnnotation_bug468207() {
+		Diagram smDiagram = editor.getActiveDiagram().getDiagramView();
+		Behavior stateMachine = ((BehavioredClassifier) editor.getModel().getOwnedType("Class1")).getOwnedBehaviors().get(0);
+
+		// Delete it, which deletes the diagram
+		DestroyElementRequest req = new DestroyElementRequest(editor.getEditingDomain(), stateMachine, false);
+		ICommand cmd = ElementEditServiceUtils.getCommandProvider(stateMachine.getContext()).getEditCommand(req);
+		editor.execute(cmd);
+
+		// The diagram was successfully deleted
+		assertThat(smDiagram.eResource(), nullValue());
+	}
+
+}
diff --git a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/src/org/eclipse/papyrus/uml/diagram/statemachine/tests/AllTests.java b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/src/org/eclipse/papyrus/uml/diagram/statemachine/tests/AllTests.java
index aa86ef762ce..705d1dd57dc 100644
--- a/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/src/org/eclipse/papyrus/uml/diagram/statemachine/tests/AllTests.java
+++ b/tests/junit/plugins/uml/diagram/org.eclipse.papyrus.uml.diagram.statemachine.tests/src/org/eclipse/papyrus/uml/diagram/statemachine/tests/AllTests.java
@@ -1,5 +1,5 @@
 /*****************************************************************************

- * Copyright (c) 2014 CEA LIST.

+ * Copyright (c) 2014, 2016 CEA LIST, Christian W. Damus, and others.

  *    

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

@@ -8,9 +8,11 @@
  *

  * Contributors:

  * Patrick Tessier (CEA LIST) - Initial API and implementation

+ * Christian W. Damus - bug 468207

  *****************************************************************************/

 package org.eclipse.papyrus.uml.diagram.statemachine.tests;

 

+import org.eclipse.papyrus.uml.diagram.statemachine.custom.helpers.tests.ZoneTest;

 import org.eclipse.papyrus.uml.diagram.statemachine.tests.canonical.AllCanonicalTests;

 import org.junit.runner.RunWith;

 import org.junit.runners.Suite;

@@ -25,6 +27,7 @@ import org.junit.runners.Suite.SuiteClasses;
 AllCanonicalTests.class,

 // load

 //LoadTests.class

+ZoneTest.class,

 })

 public class AllTests {

 }