Properly handle cache being cleared

Previously the code deleted the entry of all of the DocItems of the page
after its contents were requested once, but this caused problems when
the cache was cleared when it expired.

Instead of deleting the entry to check if it should be queued on the
next item request, we keep it and create an entry in the
_item_futures dict for all items again and check for containment there.
To avoid populating the queue multiple times with the same item in some
cases the futures cleanup task will now only run when the queue is empty

0 files changed, 0 insertions, 0 deletions