Repeated headers produce 400 Bad Request

[Bugzilla-Briareos@…]

I've filed a bug in the squid-cache bugzilla (http://www.squid-cache.org/bugs/show_bug.cgi?id=1677) that squid produces a duplicate "If-None-Match:" header in it's request, which seems to make lighttpd return a "400 Bad Request":

# telnet localhost 80
GET / HTTP/1.0
If-Modified-Since: Thu, 06 Jul 2006 09:57:57 GMT
If-None-Match: "714413461"
If-None-Match: "714413461"

HTTP/1.0 400 Bad Request
Connection: close
Content-Type: text/html
Content-Length: 349
Date: Wed, 12 Jul 2006 08:14:49 GMT
Server: lighttpd/1.4.11

But - according to RFC 2616, the repeated "If-None-Match:" header is both legal and equivalent to

If-None-Match: "714413461", "714413461"

which, if used instead, works just fine.

(Excerpt from RFC 2616:

| 4.2 Message Headers
[...]
|    Multiple message-header fields with the same field-name MAY be
|    present in a message if and only if the entire field-value for that
|    header field is defined as a comma-separated list [i.e., #(values)].
|    It MUST be possible to combine the multiple header fields into one
|    "field-name: field-value" pair, without changing the semantics of the
|    message, by appending each subsequent field-value to the first, each
|    separated by a comma. The order in which header fields with the same
|    field-name are received is therefore significant to the
|    interpretation of the combined field value, and thus a proxy MUST NOT
|    change the order of these field values when a message is forwarded.

| 14.26 If-None-Match
[...]
|        If-None-Match = "If-None-Match" ":" ( "*" | 1#entity-tag )

)

So while squid shouldn't duplicate the header in the first place, lighttpd should not produce a 400 Bad Request in response...

(Yeah, it should also probably say "HTTP/1.1" in the request from squid (which they said they won't do before they're fully 1.1 compliant), but changing the request into a valid HTTP/1.1 request still produces a 400 response code...)

[hno@…]

More bugs in If-None-Match processing. Looks like lighttpd reads If-None-Match as a string header and not a list header.

If-None-Match: "currentetag"

produces a 304

If-None-Match: "currentetag", "anotheretag"

produces a 200, where a 304 was expected..