one of the issues that needed working out was dealing with multiple ETag
headers. my original idea was to have ap_weaken_etag guarantee that ETag
headers would be weak. with ETag headers entering err_headers_out via a
third party, there exists the possibility that the server would send
multiple ETag headers for a single request. while I'm not sure if this is
actually legal, I can't find anything that says it isn't.
RFC 2616, section 3.11, BNF does not allow multiple ETag header fields.
I think you need to work on making this patch more efficient -- it is
doing too much work for an activity in the critical path of servicing
a request. BTW, an entity tag does not identify the entity -- it merely
acts as a key for cache and range request handling. If a filter
consistently produces the same content, then it should not modify the
entity tag (the routine that arranges the filters must do that if needed).
....Roy
