rem: int fd = sys_open_entry_ref(1, device, parent, name, O_RDONLY, 0);
add: if (name == NULL || parent == 0) return;  fd = sys_open_entry_ref(1, device, parent, name, O_RDONLY, 0);
context: tracker_query_file(dev_t device, ino_t parent, char *name){	struct stat stat;	int status;	int fd = sys_open_entry_ref(1, device, parent, name, O_RDONLY, 0);	if (fd < 0)	{		printf("tracker: could not open file: %s\n", name);		return;	}	status = sys_rstat(true, fd, NULL, &stat, 1);	if (status < 0) {		printf("tracker: could not stat file: %s\n", name);	}	sys_close(true, fd);}