The developers used char* ext = strrchr(filename, '.') rather than CONST char* ext. Fixed. Please switch to Yafaray instead of Yafray in the portage tree (bug 273738).
Steps to Reproduce:
1. Emerge yafray with GCC 4.4.
GCC 4.4.0-r1, rest unimportant.
Created attachment 198367 [details, diff]
patch solving the issue
Yep, that does the trick.
+ 09 Jan 2010; Samuli Suominen <email@example.com>
+ yafray-0.0.9-r1.ebuild, +files/yafray-0.0.9-gcc44.patch:
+ Fix building with GCC 4.4+ wrt #278216.
Since you didn't use realname in bugzilla, I left the credits out...