tentative correction double.c insert

Chains_across_the_Island/Fundamentals/double/double.c

@@ -28,7 +28,12 @@ int dlist_insert(struct dlist **l, size_t index, int e)
     //struct dlist *tmp = *l;
 
     if(index == 0){ 
-        dlist_append(*l, e);
+        
+        new_node->prev = NULL;
+        new_node->next = *l;
+        new_node->data = e;
+
+        //dlist_append(*l, e);
         return 0;
     }