[cairo] configure errs in determing if xrender backend supported on RHE 2.1

[Charles Tuckey]

Hi,

This is a small thing. I am compiling cairo-0.1.21 on RHE 2.1 which has 
a older version of Xrender that won't work with the cairo xlib surface.

The configure script checks for xrender.pc which it doesn't find on RHE 
2.1. Then it checks for Xrender.h. The configure script finds this and 
assumes that cairo can support the xlib surface. On RHE 2.1 this is the 
wrong assumption.

I don't know what the fix is. There doesn't appear to be any version 
info in Xrender.h. Perhaps if the pkg-config check fails then the 
assumption should be that xlib surfaces are not supported. This would be 
consistent with the way decisions about the other surfaces are made.

I am aware I can give the parameter --disable-xlib to the configure 
script. I'm just trying to help make the build process automagical.

charlie

-- 
Charles Tuckey, MSc.
Software Developer
Verano, Inc.
403.299.4765