linked list: fix ll_extend bug

pobrn · Jul 23, 2020 · 9139a93 · 9139a93
1 parent 2ba2258
commit 9139a93
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/ll.c b/ll.c
@@ -118,7 +118,12 @@ EXPORT struct ll *ll_extend(struct ll *list, struct ll *other)
 	if (!other)
 		return list;
 
-	LL_NEXT(LL_TAIL(list)) = LL_HEAD(other);
+	if (!LL_IS_EMPTY(other)) {
+		LL_NEXT(LL_TAIL(list)) = LL_HEAD(other);
+		LL_PREV(LL_HEAD(other)) = LL_TAIL(list);
+		LL_TAIL(list) = LL_TAIL(other);
+	}
+
 
 	free(other);