[Zope] URL0 returns index_html not index.html

[Mark Barratt]

Zope 2.7.4 on Debian

DTML method index_html in the root says <dtml-var "_['index.html']">

A link in a page template to

tal:attributes="href string:${context/REQUEST/URL0}/source.html

where the page is addressed by [path]/ and is actually at [path]/index.html

returns [path]/index_html/source.html

I can vaguely see why this is happening. My question: is there a 
straightforward way of making the links (and error reports) return the 
actual page address?

(I think I understand that 'actual' 'page' and 'address' are all 
metaphors which may be leading me into error... )

Thanks for any help/enlightenment.

-- 
Mark Barratt