1 files changed, 7 insertions, 2 deletions
diff --git a/ll.c b/ll.c
index 910b869..3481b8b 100644
--- a/ll.c
+++ b/ll.c
@@ -1,9 +1,14 @@
 #include <stdlib.h>
+#include <assert.h>
 #include "ll.h"
 
-llnode* appendll(llnode* tail, char* str){
+llnode* appendll(llnode* tail, /*@nottemp@*/char* str){
     llnode* new = malloc(sizeof(llnode));
-    if (tail != NULL) tail->next = new;
+    assert(new != NULL);
+    if (tail != NULL) {
+        assert(tail->next == NULL);
+        tail->next = new;
+    }
     new->str = str;
     new->next = NULL;
     return new;