1 files changed, 4 insertions, 1 deletions
diff --git a/list.c b/list.c
index 6aacfbd..6ac5421 100644
--- a/list.c
+++ b/list.c
@@ -13,6 +13,9 @@ struct list *list_create() {
 /* frees all memory associated with the list */
 void list_destroy(struct list *list) {
     struct list_node *node, *next;
+
+    if (!list)
+	return;
     
     for (node = list->first; node; node = next) {
 	free(node->data);
@@ -47,7 +50,7 @@ void *list_shift(struct list *list) {
     struct list_node *node;
     void *data;
     
-    if (!list->first)
+    if (!list || !list->first)
 	return NULL;
     
     node = list->first;