>>> Stefan Monnier on Wed, 20 Nov 2013 08:29:17 -0500 wrote:

 >> +		(and (ido-final-slash (concat dir name))
 > Can expand-file-name be used here instead of concat?

Not really. The dir is like /ssh: and the name is like "amazon:". The
concat is for ido-final-slash to see that the name actually contains the
tramp root. 

The following patch is probably a cleaner implementation of the same
idea: