X forwarding problem

[Julien Demoor]

Hi,

I'm working on a program (for Linux) that uses OpenSSH with multiplexing
and X11 forwarding. The first call to ssh has arguments -MNfX, so the
connection is only established. Later, remote commands using X are
called with "ssh -S path -fX remoteCommand".
For some obscure reason, this does not work from my program, which is
also responsible for starting the X server and setting the
authorizations. I have tried everything I could think of, without success.
It seems that the problem come from the first call to ssh. There must be
something my program does at the same time that prevents ssh from
initializing X forwarding locally. Unfortunately, even with the -vvv
option, ssh gives very little information about X forwarding (few when
it works, none when it doesn't).
I'm looking for ideas as to why ssh can't initialize X or indications to
what parts of the OpenSSH source code I should look into.

Thanks in advance for your help.


Julien Demoor