filecache: create an entry in _filecache when __set__ is called for a missing one...
filecache: create an entry in _filecache when __set__ is called for a missing one
Preserve the invariant that if P is a filecached property on X then
P in X.__dict__ => P in X._filecache.
Previously, it was possible for a filecached property to become out of sync
with the filesystem if it was set before getting it first, since the initial
filecacheentry was created in __get__.
Old behaviour:
repo.prop = x
repo.invalidate() # prop has no entry in _filecache, it's not removed
# from __dict__
repo.prop # returns x like before without checking with the
# filesystem
New:
repo.prop = x # an empty entry is created in _filecache
repo.invalidate() # prop is removed from __dict__
repo.prop # recreates prop
