Custom RSS feed for custom post type not working with qtranslate-slug plugin

[Ishanjn]

There is some issue with custom rss feed after installing "qtranslate-slug" plugin. I customised rss feed url to include my custom post type. I added custom post type into standard feed URL ex. http://www.example.com/feed/?post_type=custom_post_type and in function.php apply a hook to handled custom template for rss feed like below -

remove_all_actions('do_feed_rss2');
add_action('do_feed_rss2', 'custom_feed_rss2', 10, 1);
function custom_feed_rss2($for_comments) {
$rss_template = get_template_directory() . '/feed_custom_post_type.php';
if (get_query_var('post_type') == 'custom_post_type' && file_exists($rss_template))
load_template($rss_template);
else
do_feed_rss2($for_comments); // Call default function
}

As you look into code, i tried to get query string value using get_query_var('post_type'); but it's returning empty string. Also in template feed_custom_post_type.php i didn't get all post for this post type.

Can you please help me to resolve this problem?
A bunch of thanks in advance...!!!