[334319] Cannot open editor for unknown content types

bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java

diff --git a/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java b/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java
index 2a1c79f..67b939f 100644
--- a/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java
+++ b/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/StructuredTextEditor.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2001, 2010 IBM Corporation and others.
+ * Copyright (c) 2001, 2011 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
@@ -79,6 +79,7 @@
 import org.eclipse.jface.text.information.InformationPresenter;
 import org.eclipse.jface.text.reconciler.IReconciler;
 import org.eclipse.jface.text.source.Annotation;
+import org.eclipse.jface.text.source.ContentAssistantFacade;
 import org.eclipse.jface.text.source.DefaultCharacterPairMatcher;
 import org.eclipse.jface.text.source.ICharacterPairMatcher;
 import org.eclipse.jface.text.source.ISourceViewer;
@@ -860,7 +861,9 @@
 					}
 					
 				};
-				((StructuredTextViewer) viewer).getContentAssistFacade().addCompletionListener(fCompletionListener);
+				ContentAssistantFacade facade = ((StructuredTextViewer) viewer).getContentAssistFacade();
+				if (facade != null)
+					facade.addCompletionListener(fCompletionListener);
 			}
 		}
 
@@ -884,7 +887,9 @@
 		void dispose() {
 			ISourceViewer viewer = getSourceViewer();
 			if (viewer instanceof StructuredTextViewer) {
-				((StructuredTextViewer) viewer).getContentAssistFacade().removeCompletionListener(fCompletionListener);
+				ContentAssistantFacade facade = ((StructuredTextViewer) viewer).getContentAssistFacade();
+				if (facade != null)
+					facade.removeCompletionListener(fCompletionListener);
 			}
 
 			for (int i = 0; i < fInserters.length; i++) {