Description:
------------
This is a follow up to the bug #69592 about skipping 0-column rowsets

I've been using the suggested "if ($statement->columnCount())" workaround to avoid this problem, but it doesn't work after a non empty rowset: columnCount is not set correctly and reports the column count of the previous rowset.

Test script:
---------------
$pdo = new PDO("dblib:host=<host>;dbname=<dbname>", "username", "password");

$stmt = $pdo->query("
	SET NOCOUNT ON

	SELECT 1

	SET NOCOUNT ON

	SELECT 1
");

do
{
	echo "columns: " . $stmt->columnCount() . "\n";
	print_r($stmt->fetchAll(PDO::FETCH_ASSOC));
}
while ($stmt->nextRowset());

Expected result:
----------------
[with bug #69592]

columns: 0
Array
(
)
columns: 1
Array
(
    [0] => Array
        (
            [computed] => 1
        )

)
columns: 0
Array
(
)
columns: 1
Array
(
    [0] => Array
        (
            [computed] => 1
        )

)


Actual result:
--------------
columns: 0
Array
(
)
columns: 1
Array
(
    [0] => Array
        (
            [computed] => 1
        )

)
columns: 1
Array
(
)
columns: 1
Array
(
    [0] => Array
        (
            [computed] => 1
        )

)