Description:
------------
In commit 352117b728cd3edb8b79c7ec4e45ae060224b6ad (https://github.com/php/php-src/commit/352117b728cd3edb8b79c7ec4e45ae060224b6ad) there was a change of condition which checked whether to call:
 zend_string_release(buffer);

from:
 if (stream) {

to:
 if (buffer) {

The problem is that buffer can point either to zend_string allocated in by php_stream_copy_to_mem() or to value of the bound parameter.

If the parameter is not a resource, buffer points to the value of the bound parameter and therefore it is released which later causes memory corruption and SIGSEGV - Segmentation fault.

With the supplied patch my test configuration runs OK. (I am sorry I cannot provide a test script, but its a bunch of unit tests run in PHP unit using SQLite as Doctrine metadata and DQL query cache.)

Expected result:
----------------
SQLite3Stmt::execute() should call zend_string_release() only on buffer containing result from php_stream_copy_to_mem().

Actual result:
--------------
SQLite3Stmt::execute() calls zend_string_release() on buffer containing Z_STR_P(parameter).