Help with memory leak on zend_call_function

Hi all,

I am working on this PR: https://github.com/php/php-src/pull/4797

It implements the ability to set a userland callback function that would
allow or deny SQL queries in SQLite using its internal authorizer logic.
This is a native feature of SQLite that is currently missing from the
PHP extension.

It's quite straightforward, but I could not find much documentation on
zend_call_function and fci/fcc.

So I just tried to find existing examples that did the same (calling a
userland function callback from the C extension) and mostly used the one
from libxml.

So it works well, but I'm stuck on a memory leak, even though I'm using
zend_fcall_info_args_clear.

I'm not sure what's going on here and why.

So if someone could take a look or point me in the right direction, that
would be great :)

Thanks!