Running an inferior with non-ASCII leading directories

I was debugging a program in a directory that has non-ASCII characters
in its name.  I noticed that argv[0] in the debuggee has the non-ASCII
characters removed.  E.g., if the program is /foo/bar/xAAAAA/prog,
where AAAAA are non-ASCII characters, then argv[0] inside the inferior
prints as "/foo/bar/x/prog".

This was on GNU/Linux with GDB 7.5, which is the latest one I have on
that machine.

Is/was such a problem in GDB, and if so, is there a work-around?  Or
did I make some stupid cockpit error?

TIA