David Z Maze <dmaze@mit.edu> writes:

> nnrss is this neat theoretical concept for me, but I've never quite
> gotten it working (including through the 5.10.x series, so I'll ask
> the newsgroup).  I'm running current CVS Gnus.  If I try to subscribe
> to an RSS group, this happens:
>
>   G R http://donut.mit.edu/blog/index.rss
>   (*Gnus churns for a bit, prodding donut*)
>   Title: blog.donut
>   Description: blog.donut
>   No such newsgroup: nnrss:blog.donut

So after much hacking, I finally found out that the root of my
problems is that the RSS feed declares

<rdf:RDF 
  xmlns="http://purl.org/rss/1.0/"
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
  xmlns:dc="http://purl.org/dc/elements/1.1/"
  xmlns:admin="http://webns.net/mvcb/"
  xmlns:content="http://purl.org/rss/1.0/modules/content/"
  xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/"
> 

but nnrss-get-namespace-prefix was returning a prefix of ":" when
looking for "http://purl.org/rss/1.0/" as an XML namespace; it should
have returned "".  It turns out that you can have two distinct empty
elisp strings that are equal but not eq, so: