This method was supposed to return only the file under the dist-info
directory, but it actually returned all installed files.
The tests didn’t catch this because they were flawed; I updated them.
Thanks to Nadeem Vawda and Jeremy Kloth for testing.
As a bonus, the removal of os.path.relpath use should also fix the
Windows buildbots.
The two public functions in database default to sys.path if the given
*paths* argument is None; the private functions don’t have default
values for their arguments anymore, which is fine as the public
functions that call them pass their arguments down. Likewise in
install, the functions will pass down their *paths* arguments down to
database functions.
A one-line unneeded function in install was removed instead of being
changed, and the few remaining tests that used brute-force restoration
of sys.path have been cleaned up to use sys.path.remove.
