scp reject remote users with space in username

[Christophe LYON]

Hello,

I have noticed that since release 5.x of openssh, the scp command 
rejects remote user names with white spaces. (We have such user names on 
Windows hosts)

For instance:
$ scp myfile "my user"@machine:.
used to work with openssh-4.2p1 and fails with 5.2p1 and 5.3p1:
my user: invalid user name.

I have traced this down to revision 1.129 of scp.c which now calls okname().

OTOH, ssh "my user"@machine works.

Is this a bug, or a feature, and if so is there a workaround?

Thanks.

Christophe.