Hi, 

Ido doesn't show known hosts with read-directory-name with tramp
directories. For example /ssh: or /ftp: show completions on
read-file-name, but not on read-directory-name. This simple patch fixes
that.

If I am not mistaken this was also a request of bug#10911:

  http://emacs.1067599.n5.nabble.com/bug-10911-24-0-94-ido-read-directory-name-should-offer-known-hosts-for-completion-td4703.html


Vitalie