Fix OSS-Fuzz #371445205: Heap-use-after-free in attr_free

zend_hash_get_current_key() does not return a string with incremented
refcount, so it shouldn't get released. This release cause

Fix OSS-Fuzz #371445205: Heap-use-after-free in attr_free

zend_hash_get_current_key() does not return a string with incremented
refcount, so it shouldn't get released. This release caused a UAF later
when the attribute was destroyed. This wasn't noticed earlier because
object_init_with_constructor() was only ever tested with interned
strings.

Closes GH-16349.

show more ...