BLOB to JPG transformation broken

[joltcoke]

Configuring a BLOB column to have browser transformation set to Inline JPG and clicking on the (also broken) thumbnail will result in the following warning:

Fatal error: Uncaught TypeError: Argument 1 passed to PhpMyAdmin\Core::downloadHeader() must be of the type string, null given, called in /var/www/html/transformation_wrapper.php on line 131 and defined in /var/www/html/libraries/classes/Core.php:631 Stack trace:
#0 /var/www/html/transformation_wrapper.php(131): PhpMyAdmin\Core::downloadHeader(NULL, 'Image/JPEG')
#1 {main} thrown in /var/www/html/libraries/classes/Core.php on line 631

Open new phpMyAdmin window

Notice in ./transformation_wrapper.php#131
 Undefined variable: cn

transformation_wrapper.php is expecting "cn" to be passed on the query string, which is not the case at the moment. Manually appending &cn= fixes the issue.

[joltcoke]

            $_url_params = [
                'db'            => $this->properties['db'],
                'table'         => $meta->orgtable,
                'where_clause_sign' => Core::signSqlQuery($whereClauseMap[$row_no][$meta->orgtable]),
                'where_clause'  => $whereClauseMap[$row_no][$meta->orgtable],
                'transform_key' => $meta->orgname,
            ];

Adding 'cn' => '', to _url_params in Results.php should fix it, not sure if this is the correct fix. Happy to provide a PR if someone can confirm this is the right approach.