Bug 63485 [projection] DefaultJavaFoldingStructureProvider's element changes listener not removed
I200405211200 For each Java editor opened a DefaultJavaFoldingStructureProvider is leaked as an element change listener is not getting removed from JavaCore. When the editor is closed, a new element changed listener is added when the document is set to null. The original element changes listener (added when the editor is first opened) is never removed.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/folding/DefaultJavaFoldingStructureProvider.java
/*
		 * @see org.eclipse.jdt.core.IElementChangedListener#elementChanged(org.eclipse.jdt.core.ElementChangedEvent)
		 */
		public void elementChanged(ElementChangedEvent e) {
			IJavaElementDelta delta= findElement(fInput, e.getDelta());
			if (delta != null)
				processDelta(delta);
		}
		
		private IJavaElementDelta findElement(IJavaElement target, IJavaElementDelta delta) {
			
			if (delta == null || target == null)
				return null;
			
			IJavaElement element= delta.getElement();
			
			if (element.getElementType() > IJavaElement.CLASS_FILE)
				return null;