HTTP

This page is an attempt to document some discrepancies between browsers and RFC 2068 (and its successor, RFC 2616) because the HTTP WG seems unwilling to resolve those issues. Hopefully one day someone writes HTTP5 and takes this into account.

Header parsing: newlines

http://lists.w3.org/Archives/Public/ietf-http-wg/2014JulSep/0123.html

Header parsing: handling "duplicates"

https://bugzilla.mozilla.org/show_bug.cgi?id=376756

Content-Encoding

Under certain conditions this header needs to be stripped: http://hg.mozilla.org/mozilla-central/file/366b5c0c02d3/netwerk/protocol/http/nsHttpChannel.cpp#l4042

Not raised. Monkey patched in Fetch.

Content-Length

In cases where Content-Length doesn't equal the actual content length, browsers truncate to the Content-Length value if it's smaller, but behaviour varies if Content-Length value is larger than actual content. Test results: https://github.com/slightlyoff/ServiceWorker/issues/362#issuecomment-49011736

Content-Type parsing

Pretty sure I (Anne) raised this at some point. A trailing ";" after a MIME type is considered invalid, but works fine in all implementations.

mnot: relevant spec - http://httpwg.github.io/specs/rfc7231.html#media.type I don't remember this being raised; we can either record it as errata or work it into the next revision.

Raised:: http://www.rfc-editor.org/errata_search.php?rfc=7231&eid=4031

Potential replacement: http://mimesniff.spec.whatwg.org/#parsing-a-mime-type

Redirects

For 301 and 302 redirects browsers uniformly ignore HTTP and use GET for the subsequent request if the initial request uses an unsafe method. (And the user is not prompted.)

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2007JanMar/thread.html#msg225

mnot: See http://httpwg.github.io/specs/rfc7231.html#status.3xx

(Seems this is mostly solved now. Would still be good to explicitly require behavior here. Maybe in Fetch.)

Location header: URLs

Browsers handle relative URIs and URIs with invalid characters in interoperable fashion.

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2009JanMar/thread.html#msg276

mnot: see note in: http://httpwg.github.io/specs/rfc7231.html#header.location If there's an updated URL spec that's able to be referenced when 7231 is revised, we can point at that.

Location header: duplicates

Nothing defines what happens with multiple Location headers. Apparently if their values match it is okay, but otherwise a network error.

Location header: fragment

https://bugzilla.mozilla.org/show_bug.cgi?id=1034819

Content-Location header

Browsers cannot support this header.

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2006OctDec/thread.html#msg190

This has apparently been fixed by making Content-Location have no UA conformance criteria. (It's not clear what it's good for at this point.)

Accept header

Accept header should preferably be done without spaces.

(not raised, odinho: I came across a site that didn't like the spaces, the developer said he'd gotten it off php.net or stackoverflow. He fixed the site. This could be disputed.)

Requiring two interoperable browser implementations

To prove that RFC 2616 can be implemented there should be two compatible implementations in browsers.

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2007JanMar/0222.html

mnot: That'll happen when RFC723x go to full Standard.

Assume Vary: Cookie

http://www.ietf.org/mail-archive/web/http-state/current/msg01447.html

HTTP 0.9 (and Legacy Shoutcast support)

See https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/qS63pYso4P0/7_cMXoKXAwAJ