Bug 100429 dropping on type hierarchy method viewer updates input
20050616-0010 - Open a element in the type hierarchy - enable 'Show all inherited methods' - select a method from Object, drop it to itself - Hierarchy of Object is built Drop to itself can happen easely when clicking quickly on entries. Dropping on the method viewer should be disabled (and I think it was before)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
}
	
	/*
	 * Sets the member filter. <code>null</code> disables member filtering.
	 */	
	private void setMemberFilter(IMember[] memberFilter) {
		Assert.isNotNull(fAllViewers);
		for (int i= 0; i < fAllViewers.length; i++) {
			fAllViewers[i].setMemberFilter(memberFilter);
		}
	}	
	
	private IType getSelectableType(IJavaElement elem) {
		if (elem.getElementType() != IJavaElement.TYPE) {
			return getCurrentViewer().getTreeRootType();
		} else {
			return (IType) elem;
		}
	}
	
	private void internalSelectType(IMember elem, boolean reveal) {	
		TypeHierarchyViewer viewer= getCurrentViewer();
		viewer.removePostSelectionChangedListener(fSelectionChangedListener);
		viewer.setSelection(elem != null ? new StructuredSelection(elem) : StructuredSelection.EMPTY, reveal);
		viewer.addPostSelectionChangedListener(fSelectionChangedListener);
	}
		
	/*
	 * When the input changed or the hierarchy pane becomes visible,
	 * <code>updateHierarchyViewer<code> brings up the correct view and refreshes