rev = _git(self.upstream, 'log', '--format=%H', '-n1').strip().decode()
d = git_cache.ensure_rev_available(self.upstream, 'otherbranch', rev)
self.assertEqual(_git(d, 'show', '%s:foofile' % rev), b'foo')
rev = _git(self.upstream, 'log', '--format=%H', '-n1').strip().decode()
d = git_cache.ensure_rev_available(self.upstream, 'otherbranch', rev)
self.assertEqual(_git(d, 'show', '%s:foofile' % rev), b'foo')