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
static boolean canReuse(int style, IJavaSearchScope scope){
		if (style != fgLastStyle)
			return false;
		if (! (scope instanceof JavaWorkspaceScope))
			return false;
		if (fgTypeList == null)
			return false;
		return true;		
	}
	
	static void flush(){
		fgTypeList= null;
	}
	
	static void setConfiguration(int style){
		fgLastStyle= style;
	}
	
	static void setCachedTypes(List types){ 
		fgTypeList= types;
	}
	
	static void registerIfNecessary(){
		if (fgIsRegistered)
			return;
		JavaCore.addElementChangedListener(new DeltaListener());
		fgIsRegistered= true;
	}
	
	private static class DeltaListener implements IElementChangedListener {