Bug#288615: apache2: Issue with language negotiation exceptions

[Vincent Untz <vincent@vuntz.net>]

Package: apache2
Version: 2.0.52-3
Severity: normal


Looking at http://httpd.apache.org/docs-2.0/content-negotiation.html, I
can read this:

=======
The server will also attempt to match language-subsets when no other
match can be found. For example, if a client requests documents with the
language en-GB for British English, the server is not normally allowed
by the HTTP/1.1 standard to match that against a document that is marked
as simply en. (Note that it is almost surely a configuration error to
include en-GB and not en in the Accept-Language header, since it is very
unlikely that a reader understands British English, but doesn't
understand English in general. Unfortunately, many current clients have
default configurations that resemble this.) However, if no other
language match is possible and the server is about to return a "No
Acceptable Variants" error or fallback to the LanguagePriority, the
server will ignore the subset specification and match en-GB  against en
documents. Implicitly, Apache will add the parent language to the
client's acceptable language list with a very low quality value. But
note that if the client requests "en-GB; q=0.9, fr; q=0.8", and the
server has documents designated "en" and "fr", then the "fr" document
will be returned. This is necessary to maintain compliance with the
HTTP/1.1 specification and to work effectively with properly configured
clients.
=======

This looks good except it seems there's a small issue when Apache adds
the parent languages. I have a client that requests: "fr-fr,en-us;q=0.3"
and the server is configured like this:
AddLanguage fr .fr
AddLanguage en .en
LanguagePriority en fr

So, apache is adding the parent languages to the client request because
the server is not configured to deal with fr-fr and en-us.
However, the client gets the english page. So it seems apache is adding
the parent languages in the "en fr" order (the one defined by
LanguagePriority). I would expect apache to add the parent languages in
the order they appear in the client request, so the user can get the
french page.

Tell me if you need more informations.

Thanks,

Vincent

-- System Information:
Debian Release: 3.1
  APT prefers testing
  APT policy: (991, 'testing'), (500, 'unstable')
Architecture: i386 (i686)
Kernel: Linux 2.6.8-1-686
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)

Versions of packages apache2 depends on:
ii  apache2-mpm-prefork           2.0.52-3   Traditional model for Apache2

-- no debconf information