TCI - Possible NPE during dispose on EnumComboViewer

Change-Id: I45b5c39f859d75c21ebc9b1ee517bf5a0ced116e
Signed-off-by: Eugen Neufeld <eneufeld@eclipsesource.com>
diff --git a/bundles/org.eclipse.emf.ecp.view.core.swt/src/org/eclipse/emf/ecp/view/internal/core/swt/renderer/EnumComboViewerSWTRenderer.java b/bundles/org.eclipse.emf.ecp.view.core.swt/src/org/eclipse/emf/ecp/view/internal/core/swt/renderer/EnumComboViewerSWTRenderer.java
index 5f32645..44ea86b 100644
--- a/bundles/org.eclipse.emf.ecp.view.core.swt/src/org/eclipse/emf/ecp/view/internal/core/swt/renderer/EnumComboViewerSWTRenderer.java
+++ b/bundles/org.eclipse.emf.ecp.view.core.swt/src/org/eclipse/emf/ecp/view/internal/core/swt/renderer/EnumComboViewerSWTRenderer.java
@@ -254,7 +254,9 @@
 	@Override
 	protected void dispose() {
 		super.dispose();
-		pushValue.dispose();
+		if (pushValue != null) {
+			pushValue.dispose();
+		}
 	}
 
 	/**