Comment 3 for bug 781068

This is ~ok on a remote location, where determining if a path from list_dir() is a directory or a file is as expensive as just trying to open it. (at least in theory the one is a stat round-trip, the other is an open(.bzr/branch-format) round-trip).

In practice, it could be quite a bit more expensive.

Even further, locally it is extra expensive. The CPU overhead of Branch.open probably dominates. (arguably Branch.open() is way to slow already, but this exacerbates the problem.)