NEW - bug 374119: NPE when handling a ContextChangeEvent 
https://bugs.eclipse.org/bugs/show_bug.cgi?id=374119

Change-Id: I90df753a0c8dfb8ec3f1858c3a7c7d275378c02e
diff --git a/org.eclipse.mylyn.mft.gmf.ui/src/org/eclipse/mylyn/mft/gmf/ui/ContextDecoratorProvider.java b/org.eclipse.mylyn.mft.gmf.ui/src/org/eclipse/mylyn/mft/gmf/ui/ContextDecoratorProvider.java
index 83cfc76..779e487 100644
--- a/org.eclipse.mylyn.mft.gmf.ui/src/org/eclipse/mylyn/mft/gmf/ui/ContextDecoratorProvider.java
+++ b/org.eclipse.mylyn.mft.gmf.ui/src/org/eclipse/mylyn/mft/gmf/ui/ContextDecoratorProvider.java
@@ -316,6 +316,9 @@
 	}
 
 	void refresh(IInteractionElement element) {
+		if (element == null || element.getContentType() == null) {
+			return;
+		}
 		if (element.getContentType().equals(getDomainUIBridge().getContentType())) {
 			String handleIdentifier = element.getHandleIdentifier();
 			Collection<ContextDecorator> values = decoratorsForModel.get(handleIdentifier);