Im working with CalDAV, and I'm having a problem. The Yahoo CalDAV server appears to be completely ignoring the If-None-Match header. The "If-None-Match: *" request header is supposed to ensure that the client will not inadvertently overwrite an existing resource if the last path segment in the resourceURI turns out to already be used. This is per RFC 4791 - "Calendaring Extensions to WebDAV (CalDAV)"
The "If-Match: eTag" header works fine, which confuses me as to why "If-None-Match" is not supported.
Please advise, I really need a way to ensure I am adding a new event and not updating an existing event by accident. Thanks.