### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/DeltaProcessor.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/DeltaProcessor.java,v
retrieving revision 1.331
diff -u -r1.331 DeltaProcessor.java
--- model/org/eclipse/jdt/internal/core/DeltaProcessor.java	7 Jan 2009 16:29:42 -0000	1.331
+++ model/org/eclipse/jdt/internal/core/DeltaProcessor.java	6 Feb 2009 07:30:00 -0000
@@ -1897,7 +1897,8 @@
 				return;
 
 			case IResourceChangeEvent.PRE_REFRESH:
-				JavaModelManager.getExternalManager().refreshReferences((IProject) resource, null);
+				if (resource != null)
+					JavaModelManager.getExternalManager().refreshReferences((IProject) resource, null);
 				return;
 
 			case IResourceChangeEvent.POST_CHANGE :