bug#9197: 24.0.50; Visiting a remote file in one server, when default directory is in another one

[Dani Moncayo <dmoncayo@gmail.com>]

Recipe from "emacs -Q":

1. Change the current buffer's default directory to some path in
"host-a": M-x cd <RET> /user-a@host-a:/dir-a <RET>.
2. Try to visit some (existing) file in host-b: C-x C-f
/user-b@host-b:/path-to-some-file <RET>.

Note that, in step #2, just before hitting <RET>, the contents of the
minibuffer are:
   /user-a@host-a:/dir-a//user-b@host-b:/path-to-some-file

Expected behavior: the file "/path-to-some-file" (from "host-b") is visited.

Observed behavior: an error occurs, because Emacs tried to visit a
(nonexistent) file in "host-a", whose path is
"/user-b@host-b:/path-to-some-file".

Note also a different but related problem: the highlighting of the
minibuffer text is consistent with the current behavior (only the
"/dir-a/" part is in gray color).  Thus, this should be fixed too, to
make it consistent with the right behavior. I.e., in this example, the
part in gray should be "/user-a@host-a:/dir-a/".


In GNU Emacs 24.0.50.1 (i386-mingw-nt5.1.2600)
 of 2011-07-25 on 3249CTO
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.5) --no-opt'

-- 
Dani Moncayo