Remove password protected posts from default RSS feed

I want to remove all password protected posts from the default RSS feed. Unfortunately I was only able to find one code example, but it looks like something is missing.

function rss_filter_protected( $query ) {
    if ( $query->is_feed ) {
        add_filter( 'posts_where', 'rss_filter_password_where' );
    }
    return $query;
}
add_filter( 'pre_get_posts','rss_filter_protected' );

As soon as I save this function the RSS feed displays all post types (attachments, etc.) that are registered to the system instead of only published posts.

If possible I would like to solve this without an additional plugin.

Thanks

Answers:

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Method 1

Here’s the filter to exclude password protected posts from the default RSS feed:

function rss_filter_protected( $query ) {
    if ( $query->is_feed ) {
        $query->set( 'has_password', false );
    }
    return $query;
}
add_filter( 'pre_get_posts','rss_filter_protected' );

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