Description:
------------
I have a Postgresql (v9.3) view which contains column made from json_agg() function (array_agg works fine).
My response looks like:
array(5) {
  [0] => array(2) {
    ["aggcolumn"] => NULL
    [0] => NULL
  }
  [1] => array(2) {
    ["aggcolumn"] => string(14) "["test"]]"
    [0] => string(14) "["test"]]"
  }
  [2] => array(2) {
    ["aggcolumn"] => string(34) "["test", "test2"]]]"
    [0] => string(34) "["test", "test2"]]]"
  }
  [3] => array(2) {
    ["aggcolumn"] => string(26) "["test3"]]]]"
    [0] => string(26) "["test3"]]]]"
  }
  [4] => array(2) {
    ["aggcolumn"] => string(46) "["test2", "test3"]]]]]"
    [0] => string(46) "["test2", "test3"]]]]]"
  }
}

Test script:
---------------
try {
            $dbh = new PDO($dsn, $user, $password);
            $sth = $dbh->prepare('SELECT aggcolumn FROM view_test WHERE company_id = ? AND active_flag IS TRUE');
            $sth->execute(array(10));
            $res = $sth->fetchAll();
            var_dump($res);
        } catch (PDOException $e) {
            echo 'Connection failed: ' . $e->getMessage();
        }

Expected result:
----------------
Response should be valid JSON string.

Actual result:
--------------
As You may notice every row has a value with an extra ']' at the end, based on current iteration count. That makes string invalid JSON response