Treat empty SDL_VIDEODRIVER var to check all video drivers.
diff --git a/src/video/SDL_video.c b/src/video/SDL_video.c
index 160190d..07c7aa5 100644
--- a/src/video/SDL_video.c
+++ b/src/video/SDL_video.c
@@ -489,7 +489,7 @@ SDL_VideoInit(const char *driver_name)
if (driver_name == NULL) {
driver_name = SDL_getenv("SDL_VIDEODRIVER");
}
- if (driver_name != NULL) {
+ if (driver_name != NULL && *driver_name != 0) {
const char *driver_attempt = driver_name;
while(driver_attempt != NULL && *driver_attempt != 0 && video == NULL) {
const char* driver_attempt_end = SDL_strchr(driver_attempt, ',');