HashTableIterators of empty hashtables are not poisoned upon destruction

Description

Using the zend_hash_iterators_* API, non-empty arrays are properly marked as poisoned in the HashTableIterator entries when destroyed.

However there is an edge case: if nNumUsed == 0 (thanks to deletion of entries during iteration), then the zend_hash_iterators_remove call is skipped in zend_hash_destroy.

Thus, we either should:
a) fix this by always calling the removal ... or
b) completely remove the auto-removal on destruction and leave it the extension authors responsibility to clear the iterators (making zend_hash_iterators_remove public API)

From the perspective of the code in php-src there is no need to have the auto-removal on free, as every iterating thing holds a reference to it.

PHP Version

master

Operating System

No response

Rà soát đường đi của zend_hash_destroy cùng với zend_hash_iterators_remove, tập trung vào trường hợp nNumUsed == 0 sau khi xóa trong quá trình lặp. Xác định hành vi dọn dẹp iterator nào mà API cần đảm bảo, sau đó kiểm tra rằng các hashtable rỗng và không rỗng để lại trạng thái poisoned như mong đợi.