tramp inconsistent completion over default directory

[Yuri D'Elia]

Using emacs+tramp from master here.
When I try to open a location using the syntax:

/-:remote:<TAB>

the contents of the home directory on the remote host are shown.
Assuming a "projects/" subdirectory exists, when I try to complete it:

/-:remote:proj<TAB>

I get "no match". But if I type manually the path until the first slash:

/-:remote:projects/<TAB>

everything works from then onwards. So it seems that completion in the
home directory doesn't work as a special case (again, no slash?).

If I explicitly use ~ (/-:remote:~/proj<TAB>) the completion works as
intended.