proper way of doing list move

libasn1parser/asn1p_list.h

@@ -10,9 +10,15 @@
 		type**tq_tail;				\
 	}
 
-#define	TQ_HEAD_COPY(to, from)			\
-	do { (to)->tq_head = (from)->tq_head;	\
-	(to)->tq_tail = (from)->tq_tail; } while(0)
+#define	TQ_MOVE(to, from)	do {			\
+	if(&(TQ_FIRST(from)) == (from)->tq_tail) {	\
+		TQ_INIT(to);				\
+	} else {					\
+		(to)->tq_head = (from)->tq_head;	\
+		(to)->tq_tail = (from)->tq_tail;	\
+	}						\
+	TQ_INIT(from);					\
+	} while(0)
 
 #define	TQ_ENTRY(type)					\
 	struct {					\