Well, the test program should test the result of `gtk_init_check()` and early out, but what to return, if it returns failure any environment where it doesn't init is left with a failure to handle, but on the other hand return success isn't right either as it gives the impression the test ran. I can see why @kugel- ignored it.
My personal approach would be to return fail unless the whole test ran, and environments where the test cannot run need to disable it.