OpenSearch: search more than one parameter

OpenSearch does not work as expected when specifying more than one search paramenter.

Example:

1. Create a query to to search the string "lorem" in Colfluence. The URL of the search is:

   <CONFLUENCE_URL>/plugins/servlet/opensearch?query=lorem&format=rss_2.0

   The results, as seen in OpenSearch1.png, are correct.

2. Lets filter the results only to pages by adding type:page. The URL in this case is:

   <CONFLUENCE_URL>/plugins/servlet/opensearch?query=lorem%26type=page&format=rss_2.0

   Even when most of the previous results where pages, in this case the search return no results, as seen in OpenSearch2.png.

This happen for any parameters added. It only works fine if you specify only one search condition. For example this URL provides the expected results:

<CONFLUENCE_URL>/plugins/servlet/opensearch?query=type:page&format=rss_2.0