AddRef texture only if there is one for the requested stage.
[wine] / dlls / glu32 /
drwxr-xr-x   ..
-rw-r--r-- 53 .cvsignore
-rw-r--r-- 283 Makefile.in
-rw-r--r-- 20939 glu.c
-rw-r--r-- 3302 glu32.spec