Failed prepare() calls aren't checked in Collection\Mysql

[elazar]

It's possible for the prepare() call on this line to fail and return a boolean value of false (e.g. if the database is missing the relevant table), but there's no check for this (e.g. one equivalent to the one for the execute() call below it).

Here's an example of a refactor that might add this check:

/**
 * Fetch the data matching the results of the SQL operation
 *
 * @param string $sql SQL statement
 * @param array $data Data to use in fetch operation
 * @param boolean $single Only fetch a single record
 * @return array Fetched data
 */
public function fetch($sql, array $data = array(), $single = false)
{
    $sth = $this->getDb()->prepare($sql);
    if ($this->isFailure($sth, $sth)) {
        return false;
    }

    $result = $sth->execute($data);
    if ($this->isFailure($sth, $result)) {
        return false;
    }

    $results = $sth->fetchAll(\PDO::FETCH_ASSOC);
    return ($single === true) ? array_shift($results) : $results;
}

/**
 * @param PDOStatement|boolean $sth
 * @param mixed $result
 * @return boolean TRUE if $result indicates failure, FALSE otherwise
 */
private function isFailure($sth, $result)
{
    if ($result === false) {
        $error = $sth->errorInfo();
        $this->lastError = 'DB ERROR: ['.$sth->errorCode().'] '.$error[2];
        error_log($this->lastError);
        return true;
    }
    return false;
}

[enygma]

Looks good to me - mind dropping that into a PR?