diff -r 104e75d18ede -r 9574a181ec26 src/string_list.c
--- a/src/string_list.c	Wed May 22 10:57:17 2013 +0200
+++ b/src/string_list.c	Wed May 22 13:00:36 2013 +0200
@@ -40,19 +40,28 @@
 }
 
 void destroy_string_list_t(string_list_t* list) {
-  if (list->items != NULL) {
-    free(list->items);
-  }
-  free(list);
-}
-
-void add_string(string_list_t* list, char* item) {
-  char** reallocated_list =
-    realloc(list->items, sizeof(char*) * (list->count + 1));
-  if (reallocated_list != NULL) {
-    list->items = reallocated_list;
-    list->items[list->count] = item;
-    list->count++;
+  if (list) {
+    if (list->items) {
+      free(list->items);
+    }
+    free(list);
   }
 }
 
+/* Adds an item to the list, if a NULL-list is specified, the item will
+ * be freed. This way a NULL-list can be used as garbage bin.
+ */
+void add_string(string_list_t* list, char* item) {
+  if (list) {
+    char** reallocated_list =
+      realloc(list->items, sizeof(char*) * (list->count + 1));
+    if (reallocated_list != NULL) {
+      list->items = reallocated_list;
+      list->items[list->count] = item;
+      list->count++;
+    }
+  } else {
+    free(item);
+  }
+}
+