Bug#431925: xserver-xorg-input-evtouch: Doesn't move pointer and most times crashes X on

["Martin Letenay" <mle@whitestein.com>]

I've also faced consistent crashes of X server anytime I've touched the
touchscreen on my unstable at amd64(x86_64).

After a lot of trials and errors with the package source I've found a fix:

Add the following code snippet to the beginning of libtouch.c :

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

The include was present in evtouch.c but was missing in libtouch.c.

It's been 10 years since I coded in C last time, so I don't exactly
understand why this helps, but it does.
It seems to be related to some x64 compile directive ? 
Someone knowledgeable may have an explanation ...

Regards,
Martin