[cairo] _cairo_directfb_is_similar undeclared in cairo-directfb-surface.c

[Hans-Jürgen Koch]

I'm trying to compile cairo-1.4.8 with directfb enabled, and get this error:

cairo-directfb-surface.c:1575: error: '_cairo_directfb_is_similar' undeclared here (not in a function)

grep doesn't find that identifier in any *.c/*.h file. Can I simply set this pointer to NULL?

Thanks,
Hans