[PATCH:app/xdm] Replace -D_XOPEN_SOURCE & -D_BSD_SOURCE with AC_USE_SYSTEM_EXTENSIONS

[Julien Cristau]

On Fri, Sep 11, 2009 at 11:11:10 -0700, Alan Coopersmith wrote:

> Signed-off-by: Alan Coopersmith <alan.coopersmith at sun.com>
> ---
>  Since this mostly affects Linux systems, I'd appreciate those with more
>  experience there confirming this is the right idea.  
>  
>  AC_USE_SYSTEM_EXTENSIONS defines _GNU_SOURCE, which seems to include
>  both _BSD_SOURCE & _XOPEN_SOURCE if I read features.h correctly, but
>  may have other side effects.    xdm seems to build fine with this patch
>  on Fedora 11, but I haven't tested it extensively.
> 
I've been building with _GNU_SOURCE on Debian since June, seems to work
fine.

Acked-by: Julien Cristau <jcristau at debian.org>

Cheers,
Julien