Subject: issue 201, was: header parsing, trailing OWS

From: Julian Reschke <[email-masked]>
Date: Thu, 21 Jan 2010 17:14:12 +0100

Julian Reschke wrote:
> Hi,
> 
> in part 1 we currently say:
> 
> "The field value MAY be preceded by optional whitespace; a single SP is 
> preferred. The field-value does not include any leading or trailing 
> white space: OWS occurring before the first non-whitespace character of 
> the field-value or after the last non-whitespace character of the 
> field-value is ignored and MAY be removed without changing the meaning 
> of the header field." -- 
> <http://greenbytes.de/tech/webdav/draft-ietf-httpbis-p1-messaging-07.html#rfc.section.4.2.p.4> 
> 
> 
> In the current edits, the last 'MAY' is a 'SHOULD', which makes it read
> 
> "A field value MAY be preceded by optional whitespace (OWS); a single SP 
> is preferred. The field value does not include any leading or trailing 
> white space: OWS occurring before the first non-whitespace character of 
> the field value or after the last non-whitespace character of the field 
> value is ignored and SHOULD be removed without changing the meaning of 
> the header field."
> 
> I think what we really should say is that they MAY be removed before 
> passing the field-value to a specific header parser, thus definitions of 
> headers MUST NOT make the presence of trailing/leading whitespace 
> semantically significant.

Now tracked as <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/201>.

Best regards, Julian

---

From: Julian Reschke <[email-masked]>
Date: Thu, 21 Jan 2010 17:39:23 +0100

Julian Reschke wrote:
>> "The field value MAY be preceded by optional whitespace; a single SP 
>> is preferred. The field-value does not include any leading or trailing 
>> white space: OWS occurring before the first non-whitespace character 
>> of the field-value or after the last non-whitespace character of the 
>> "A field value MAY be preceded by optional whitespace (OWS); a single 
>> SP is preferred. The field value does not include any leading or 
>> trailing white space: OWS occurring before the first non-whitespace 
>> character of the field value or after the last non-whitespace 
>> character of the field value is ignored and SHOULD be removed without 
>> changing the meaning of the header field."
>>
>> passing the field-value to a specific header parser, thus definitions 
>> of headers MUST NOT make the presence of trailing/leading whitespace 
> ...

I believe this is a purely editorial issue; the text in draft 8 was 
confusing after a minor change from draft 7.

I have now made it say:

"A field value MAY be preceded by optional whitespace (OWS); a single SP 
is preferred. The field value does not include any leading or trailing 
white space: OWS occurring before the first non-whitespace character of 
the field value or after the last non-whitespace character of the field 
value is ignored and SHOULD be removed before further processing (as 
this does not change the meaning of the header field)."

(<http://trac.tools.ietf.org/wg/httpbis/trac/changeset/748>)

Best regards, Julian