+void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
+/* Transfers an interim allocation from one query to another, so that
+ * the `to' query will have room for the data when we get to makefinal
+ * and so that the free will happen when the `to' query is freed
+ * rather than the `from' query.
+ *
+ * It is legal to call adns__transfer_interim with a null pointer; this
+ * has no effect.
+ *
+ * _transfer_interim also ensures that the expiry time of the `to' query
+ * is no later than that of the `from' query, so that child queries'
+ * TTLs get inherited by their parents.
+ */
+