- From: Henrik Nordstrom <henrik@henriknordstrom.net>
- Date: Sat, 13 Jun 2009 01:48:35 +0200
- To: Brian Smith <brian@briansmith.org>
- Cc: "'Mark Nottingham'" <mnot@mnot.net>, "'HTTP Working Group'" <ietf-http-wg@w3.org>
mån 2009-06-01 klockan 14:22 -0500 skrev Brian Smith: > Mark Nottingham wrote: > > The text in question is in p3 section 3.2.1: > > > If and only if the media type is not given by a Content-Type field, > > > the recipient MAY attempt to guess the media type via inspection of > > > its content and/or the name extension(s) of the URI used to identify > > > the resource. If the media type remains unknown, the recipient > > > SHOULD treat it as type "application/octet-stream". > > "If and only if...MAY..." is not the same as "MUST NOT ... if not". That is, > the above statement doesn't forbid an implementation from doing content > sniffing since it isn't a MUST NOT requirement. Correct, it's just a SHOULD NOT, which is the level it should be. The text as-is tries to say that receiving agents SHOULD NOT attempt to guess the media type of the message if there is an Content-Type indication. This means that from the protocol perspective it's recommended the media type indication in the protocol is what is used for determining the media type of the enclosed entity. This does not forbid agents from using other means for finding the media type as there is no MUST level requirements, but clearly sets the tone on what the HTTP protocol considers as authoritative media type indication for the entity contained within the HTTP message. Imho the correct resolution of #155 is to remove just the text "and only if", softening the tone just slightly. Removing the whole condition on when guessing/sniffing is allowed opens it up too much, downgrading the whole text almost to the level of pure ignorance, giving a general MAY level rule that sniffing/guessing of the media type is allowed under all conditions which is not what the HTTP protocol intends. Regards Henrik
Received on Friday, 12 June 2009 23:49:24 UTC