PDOStatement::nextRowSet() is broken in MySQL 5.6.16 on Windows - php

Question

This question without an accepted answer raises a catastrophic problem with MySQL that I am experiencing on MySQL version 5.6.16 on Windows in a modified form.
The problem is easily reproducible: I include it here (copied from the above-linked question, but with changes applicable to my code):
$pdo = /* connection stuff here */
$sql = "call test();"; // call stored procedure - see below
$statement = $connection->query($sql);
do {
$rowset = $statement->fetchAll(PDO::FETCH_ASSOC);
if($rowset) {
// Do stuff with $rowset
}
} while($statement->nextRowset());
Here is the definition of the stored procedure test:
DELIMITER $$
DROP PROCEDURE IF EXISTS `test`$$
CREATE PROCEDURE `test`()
BEGIN
SELECT 1; SELECT 2; SELECT 3; SELECT 4;
END$$
DELIMITER ;
The only difference between my code, and the above-linked code, is that I pack the SQL query into a stored procedure.
In my case, the while statement returns true four times, rather than three times (it should be just three times). After the fourth time, fetchAll(...) throws a SQLSTATE[HY000]: General error error.
Unfortunately, this problem is catastrophic. There is no other way with PDO to iterate to following rowsets other than using the nextRowSet() function. Therefore, I may revert to a previous version of MySQL in order to work around this issue.
I have found two links that seem to indicate this issue, listed here:
https://bugs.php.net/bug.php?id=67130 and
http://permalink.gmane.org/gmane.comp.php.devel/81518
I would appreciate a confirmation that this is, indeed, a bug with version 5.6.16 of MySQL on Windows. Even more, I would appreciate a workaround. Thanks.

Answer 1

I had same problem with PDO::nextRowset(), as it returns true even there are no more rowsets available, therefore when calling fetchAll(), it raises exception HY000. (tested on PHP 5.5.12 windows, Mysql 5.5.17 linux)
A workaround for this problem is to check number of columns with method PDO::columnCount() before fetching rowset. If it is non-zero, you have a valid rowset, and thus you could call PDO::fetchAll().
Even if PDO::nextRowset() reports true, columnCount() will report number of columns before moving to next rowset.
Example:
while ($objQuery->columnCount()) {
$tab[] = $objQuery->fetchAll(\PDO::FETCH_ASSOC);
$objQuery->nextRowset();
}

Answer 2

If the problem is being caused by multiple result sets, then maybe the best work around would be to find ways of avoiding multiple result sets in a single query.
For example, if the expected results are in the same format (which I expect they probably are because you intend to use the same code to deal with all of them) then you could potentially use UNION to compound the four queries together.
SELECT 1
UNION ALL
SELECT 2
UNION ALL
SELECT 3
UNION ALL
SELECT 4;
Failing that, you can execute a separate query for each SELECT and hand the result off to a function to do the processing.