If an entry is Prefetched, it's parent may not have a cached List entry but it may have originated from an earlier ancestor. If there's an immediate parent that listed the entry still clear it, but if not search for an ancestor that prefetched child entries and clear that instead.
If an entry is Prefetched, it's parent may not have a cached List entry but it may have originated from an earlier ancestor. If there's an immediate parent that listed the entry still clear it, but if not search for an ancestor that prefetched child entries and clear that instead.
Fixes #770.