There are two problems with list_remove_elem function in objc/objc-list.h file:
- function dumps core when remove first element of the list,
- if element is in the list more than once and copy of the element are one by one they do not be removed all.

    struct objc_list *list = 0;
    int elem_1 = 1;
    int elem_2 = 2;
    int elem_3 = 3;

    list = list_cons((void *)&elem_1, list);
    list = list_cons((void *)&elem_2, list);
    list = list_cons((void *)&elem_2, list);
    list = list_cons((void *)&elem_2, list);
    list = list_cons((void *)&elem_3, list);

    list_remove_elem(&list, (void *)&elem_2); // Remove only 2 elem_2!

    list_remove_elem(&list, (void *)&elem_1); // Core dumps!

After list_remove_head should have not changed pointer to tail. The following patch repair both problems.

--- /usr/include/objc/objc-list.h       2006-04-20 11:55:22.000000000 +0200
+++ objc-list.h 2009-01-16 21:05:04.000000000 +0100
@@ -106,7 +106,11 @@
 {
   while (*list) {
     if ((*list)->head == elem)
-      list_remove_head(list);
+      {
+        list_remove_head(list);
+        continue;
+      }
+
     list = &((*list)->tail);
   }
 }