Allocator is considered initialized after first sys_alloc, not during initialize_allocator.

src/initialize_allocator.c

@@ -144,8 +144,6 @@ void initialize_allocator(allocator_t *allocator) {
     (maptablenode+1)->next = NULL;
 #endif /* WITH_FIXED_LISTS */
 
-    allocator->initialized = true;
-
 #ifdef HAVE_LOCKS
     sbrk_unlock();
 #endif /* HAVE_LOCKS */

src/sys_alloc.c

@@ -57,6 +57,7 @@ void *sys_alloc(allocator_t *allocator, heap_t *heap, size_t size) {
     } else {
         previous_size = 0;
         previous_size_availability = 1; /* Occupied and of 0 size */
+        allocator->initialized = true;
     }
 
 #ifndef WITH_MEMORY_SPACE_AWARENESS