Bug 5092 Open type list - no longer works if ever cancelled during indexing
Build 205 Attempting to patch a binary project. I manually expanded its sources in a source folder, and then force a refresh from local. Then immediatly, I tried to open the type I wanted to patch, I got a dialog indicating that indexing was still in progress. I then cancelled my action (open type), and got a "No types available". Tried again later. The dialog came up again with "No types available", even though indexing was finished by then. It seems to have cached the empty list, and I remember this bug around 0.9.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/util/TypeCache.java
if (delta.getElement().getElementType() == IJavaElement.COMPILATION_UNIT)
				return false;
					
			
			if (delta.getFlags() != IJavaElementDelta.F_CHILDREN)
				return true;
	
			
			if (delta.getElement().getElementType() == IJavaElement.TYPE)
				return false;
	
			if ((delta.getAddedChildren() != null)
				&& (delta.getAddedChildren().length != 0))
				return true;
	
			return false;
		}
	
		/*
		 * returns false iff list is flushed and we can stop processing
		 */
		private boolean processDelta(IJavaElementDelta delta) {
			if (mustStopProcessing(delta))
				return true;
	
			if (mustFlush(delta)) {
				flush();
				return false;
			}
			IJavaElementDelta[] affectedChildren= delta.getAffectedChildren();