python: Handle the possibility that no driver is selected.

diff --git a/src/gallium/state_trackers/python/st_softpipe_winsys.c b/src/gallium/state_trackers/python/st_softpipe_winsys.c
index cd3e786..9853741 100644 (file)
--- a/src/gallium/state_trackers/python/st_softpipe_winsys.c
+++ b/src/gallium/state_trackers/python/st_softpipe_winsys.c
@@ -46,6 +46,8 @@ st_software_screen_create(void)
    default_driver = "llvmpipe";
 #elif defined(HAVE_SOFTPIPE)
    default_driver = "softpipe";
+#else
+   default_driver = "";
 #endif
 
    ws = null_sw_create();