"William A. Rowe, Jr." <wr...@rowe-clan.net> writes: > Joe Orton wrote: >> >> Does 2616 mandate that a resource must always >> exactly the same set of content-codings across methods and time? >> (AFAICT there is no MUST on that front; it's a SHOULD if anything) > > Read through to the end, it breaks all proxied content; > > 9.4 HEAD > > The HEAD method is identical to GET except that the server MUST NOT > return a message-body in the response. The metainformation contained > in the HTTP headers in response to a HEAD request SHOULD be identical > to the information sent in response to a GET request. This method can > be used for obtaining metainformation about the entity implied by the > request without transferring the entity-body itself. This method is > often used for testing hypertext links for validity, accessibility, > and recent modification. > > The response to a HEAD request MAY be cacheable in the sense that the > information contained in the response MAY be used to update a > previously cached entity from that resource. If the new field values > indicate that the cached entity differs from the current entity (as > would be indicated by a change in Content-Length, Content-MD5, ETag > or Last-Modified), then the cache MUST treat the cache entry as > stale.
Doesn't that last sentence just indicate that the cache entry will be invalidated? That would add some possibly unnecessary work fetching the content again the next time it's requested, but I wouldn't think it would break anything. -- Dan Poirier <poir...@pobox.com>
