bug#30195: 26.0.91; emacs-26: eww incorrectly follows relative link in debian reference manual

[Lars Ingebrigtsen <larsi@gnus.org>]

Eric Brown <brown@fastmail.com> writes:

> Tested with 'emacs -Q'.  The operating system is Debian Testing
> (buster), with emacs-26 head.
>
> With eww, browse to file:///usr/share/debian-reference.  This is the
> landing page which leads to the Debian Reference manuals various
> languages.
>
> Attempt to follow the link to English: HTML (multi files) and rather
> than going to:
>
> file:///usr/share/debian-reference/index.en.html
>
> eww attempts to go to:
>
> file:///usr/share/index.en.html
>
> instead of:
>
> file:///usr/share/debian-reference/index.en.html

The problem here is that file:///usr/share/debian-reference doesn't
exist.  But if you run url-retrieve on that, the URL library helpfully
roots around in that directory to see whether it can find a likely file
to display instead, and it finds
file:///usr/share/debian-reference/index.html.  But it doesn't report
this back to eww in any way, so eww thinks that the document is
file:///usr/share/debian-reference, and so all the references are wrong.

I don't really know what to do about this corner case...

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no