XSLT and autoindex XML output: conditionally transform XML only when it's autoindex output?

[Moritz Wilhelmy]

Hi,

The documentation said it's possible to transform XML dirlistings into
XHTML in order to customize what they look like, so I did one that makes
them look like lighttpd's:
https://gist.github.com/wilhelmy/5a59b8eea26974a468c9

This works fine, but does anybody know how I apply the XSLT only
to transform directory indexes but not other XML files that might be
around? Currently, the way this config works is that all XML files are
being transformed by this stylesheet.

The config looks like this:
https://gist.github.com/wilhelmy/5a59b8eea26974a468c9#file-nginx-snippet-conf

Thanks and best regards,

Moritz