Julian Reschke from the IETF WebDAV WG filed a PR saying that we were in violation of the RFC because mod_dav didn't allow weak entity tags. This is part of the 'Summary of If header eval tests' thread on the w3c-dist-auth mailing list.Allow mod_dav to do weak entity comparison function rather than a strong entity comparison function. (i.e. it will optionally strip the W/ prefix.)That doesn't really follow the spirit of etag validation in HTTP. In theory, the client is not allowed to use weak etags for anything other than cache consistency checks, so this won't help any client that is actually HTTP-compliant. It would be better to send a strong entity tag in the first place.
The problem has to do when a weak entity tag is generated on a file that has just changed (therefore, MUST be weak). When a request tries to use that weak entity tag on a If: in a subsequent request (after the etag is now strong), mod_dav would reject it because it was weak.
Julian said that was incorrect behavior. I'm not currently in a position to disagree. Feel free to disagree with him. I have to admit that this area is *very* unclear in the RFCs. I tend to say that we should be forgiving in this case (liberal in what you accept, blah, blah). But, I have no problem backing it out if the protocol gurus say so. =) -- justin
