Feed format: Returns empty file for empty query result

[s7eph4n]

When a query returns a result with 0 entries the feed format will return an empty file (looks like an HTTP 500, but isn't).
I don't know the spec for RSS, so this may actually be correct behavior, but intuitively I would have expected some valid XML, just without any entries. Something like

<?xml version="1.0"?>
<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
    <channel>
        <title>Testwiki</title>
        <link>http://127.0.0.1/mw/index.php/Special:Ask</link>
        <description>From Testwiki</description>
        <language>en</language>
        <generator>MediaWiki 1.27alpha</generator>
        <lastBuildDate>Wed, 24 Feb 2016 23:04:48 GMT</lastBuildDate>
    </channel>
</rss>

[JeroenDeDauw]

I don't know the spec either, but this is also how I expect it to work.

[mwjames]

After a superficial look into FeedResultPrinter, how about?

    protected function getResultText( SMWQueryResult $res, $outputMode ) {

        if ( $outputMode == SMW_OUTPUT_FILE ) {
            if ( $res->getCount() == 0 ){
                $res->addErrors( array( $this->getContext()->msg( 'smw_result_noresults' )->inContentLanguage()->text() ) );
-               return '';
+           //  return '';

to return something like:

<rss xmlns:dc="http://purl.org/dc/elements/1.1/" version="2.0">
<channel>
<title>mw-26-00</title>
<link>
http://localhost:8080/mw-26-00/index.php/Special:Ask
</link>
<description>From mw-26-00</description>
<language>en</language>
<generator>MediaWiki 1.26.0</generator>
<lastBuildDate>Thu, 25 Feb 2016 09:13:48 GMT</lastBuildDate>
</channel>
</rss>

[s7eph4n]

👍