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Re: If-Match header question

From: Julian Reschke <julian.reschke@gmx.de>
Date: Tue, 23 Aug 2005 19:09:42 +0200
Message-ID: <430B5856.9090505@gmx.de>
To: Wilfredo Sánchez Vega <wsanchez@wsanchez.net>
CC: Webdav WG <w3c-dist-auth@w3c.org>

Wilfredo Sánchez Vega wrote:
>>>   However, it goes on to say that if, without the If-Match  header,  
>>> the request would have resulted in a 200-series response,  that the  
>>> header must be ignored.
>>
>>
>> ..other than a 2xx or a 412 (<http://greenbytes.de/tech/webdav/ 
>> rfc2616.html#rfc.section.14.24.p.6>):
>>
>> "If the request would, without the If-Match header field, result in  
>> anything other than a 2xx or 412 status, then the If-Match header  
>> MUST be ignored."
>>
>> So this has indeed been fixed.
> 
> 
>   No, my concern isn't about 412.  My concern is about any other  

I see. I thought that including the 412 into the sentence would resolve 
the issue, but it doesn't :-)

> possible error, such as permission errors, or other errors specific  to 
> the operation being requested.  In the case of PUT, if the PUT  would 
> fail due to a filesystem error which would result in an error  response 
> (for example, disk is full and a 507 is appropriate), the  spec as 
> written requires that I ignore the If-Match header.

Yes.

>   The problem is that in some cases, the only way to know what the  
> error condition would be is to actually try the operation.  Doing so  
> could be expensive, and could require restoring everything back to  its 
> original state when you find out that there is, in fact, no  error, 
> which is presumably the most common case.

I absolutely agree, and I don't think anybody actually implements this 
per spec. You probably should report this to the HTTP WG 
(<ietf-http-wg@w3.org>).

Best regards, Julian
Received on Tuesday, 23 August 2005 17:10:56 GMT

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