commit: remove special handling of IOError (actually dead code)
In the past, IOError was used to mark a file as removed. The differentiation
between OSError and IOError in this place was introduced in
e553a425751d, to
avoid that “normal” OSErrors / IOErrors accidentally mark files as removed.
This weird internal API was removed in
650b5b6e75ed. It seems like that
changeset should have removed the differentiation, at least I don’t see any
reason for keeping it.
On Python 3, OSError and IOError are aliased. Therefore the removed code was
actually dead.
py3: catch specific OSError subclasses instead of checking errno
On Python 3, the "not a directory" error is mapped to ENOTDIR instead of
EINVAL. Therefore, catching the NotADirectoryError subclass is sufficient.