+/*
+ return 1 if ptr is a parent of context
+*/
+static int _talloc_is_parent(const void *context, const void *ptr)
+{
+ struct talloc_chunk *tc;
+
+ if (context == NULL) {
+ return 0;
+ }
+
+ tc = talloc_chunk_from_ptr(context);
+ while (tc) {
+ if (TC_PTR_FROM_CHUNK(tc) == ptr) {
+ return 1;
+ }
+ while (tc && tc->prev) tc = tc->prev;
+ if (tc) {
+ tc = tc->parent;
+ }
+ }
+ return 0;
+}
+
+/*
+ move a lump of memory from one talloc context to another return the
+ ptr on success, or NULL if it could not be transferred.
+ passing NULL as ptr will always return NULL with no side effects.
+*/
+static void *__talloc_steal(const void *new_ctx, const void *ptr)
+{
+ struct talloc_chunk *tc, *new_tc;
+
+ if (unlikely(!ptr)) {
+ return NULL;
+ }
+
+ if (unlikely(new_ctx == NULL)) {
+ new_ctx = null_context;
+ }
+
+ tc = talloc_chunk_from_ptr(ptr);
+
+ if (unlikely(new_ctx == NULL)) {
+ if (tc->parent) {
+ _TLIST_REMOVE(tc->parent->child, tc);
+ if (tc->parent->child) {
+ tc->parent->child->parent = tc->parent;
+ }
+ } else {
+ if (tc->prev) tc->prev->next = tc->next;
+ if (tc->next) tc->next->prev = tc->prev;
+ }
+
+ tc->parent = tc->next = tc->prev = NULL;
+ return discard_const_p(void, ptr);
+ }
+
+ new_tc = talloc_chunk_from_ptr(new_ctx);
+
+ if (unlikely(tc == new_tc || tc->parent == new_tc)) {
+ return discard_const_p(void, ptr);
+ }
+
+ if (tc->parent) {
+ _TLIST_REMOVE(tc->parent->child, tc);
+ if (tc->parent->child) {
+ tc->parent->child->parent = tc->parent;
+ }
+ } else {
+ if (tc->prev) tc->prev->next = tc->next;
+ if (tc->next) tc->next->prev = tc->prev;
+ }
+
+ tc->parent = new_tc;
+ if (new_tc->child) new_tc->child->parent = NULL;
+ _TLIST_ADD(new_tc->child, tc);
+
+ return discard_const_p(void, ptr);
+}