diff -r 62f1a55535e7 -r 0b33b9396851 ucx/list.c
--- a/ucx/list.c	Mon Feb 04 14:46:11 2019 +0100
+++ b/ucx/list.c	Mon Feb 04 17:49:50 2019 +0100
@@ -1,7 +1,7 @@
 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
- * Copyright 2016 Olaf Wintermann. All rights reserved.
+ * Copyright 2017 Mike Becker, Olaf Wintermann All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -26,7 +26,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "list.h"
+#include "ucx/list.h"
 
 UcxList *ucx_list_clone(UcxList *l, copy_func fnc, void *data) {
     return ucx_list_clone_a(ucx_default_allocator(), l, fnc, data);
@@ -77,6 +77,7 @@
 }
 
 void ucx_list_free_content(UcxList* list, ucx_destructor destr) {
+    if (!destr) destr = free;
     while (list != NULL) {
         destr(list->data);
         list = list->next;
@@ -106,41 +107,6 @@
     }
 }
 
-UcxList *ucx_list_append_once(UcxList *l, void *data,
-        cmp_func cmpfnc, void *cmpdata) {
-    return ucx_list_append_once_a(ucx_default_allocator(), l,
-            data, cmpfnc, cmpdata);
-}
-
-UcxList *ucx_list_append_once_a(UcxAllocator *alloc, UcxList *l, void *data,
-        cmp_func cmpfnc, void *cmpdata) {
-
-    UcxList *last = NULL;
-    {
-        UcxList *e = l;
-        while (e) {
-            if (cmpfnc(e->data, data, cmpdata) == 0) {
-                return l;
-            }
-            last = e;
-            e = e->next;
-        }
-    }
-    
-    UcxList *nl = ucx_list_append_a(alloc, NULL, data);
-    if (!nl) {
-        return NULL;
-    }
-
-    if (last == NULL) {
-        return nl;
-    } else {
-        nl->prev = last;
-        last->next = nl;
-        return l;
-    }
-}
-
 UcxList *ucx_list_prepend(UcxList *l, void *data) {
     return ucx_list_prepend_a(ucx_default_allocator(), l, data);
 }
@@ -241,7 +207,7 @@
 }
 
 static UcxList *ucx_list_sort_merge(int length,
-        UcxList* restrict ls, UcxList* restrict le, UcxList* restrict re,
+        UcxList* ls, UcxList* le, UcxList* re,
         cmp_func fnc, void* data) {
 
     UcxList** sorted = (UcxList**) malloc(sizeof(UcxList*)*length);
@@ -291,7 +257,7 @@
     UcxList *lc;
     int ln = 1;
 
-    UcxList *restrict ls = l, *restrict le, *restrict re;
+    UcxList *ls = l, *le, *re;
     
     // check how many elements are already sorted
     lc = ls;