http://issues.apache.org/bugzilla/show_bug.cgi?id=39727
We have some controversy surrounding this bug, and bugzilla has turned into a technical discussion that belongs here. Fundamental question: Does a weak ETag preclude (negotiated) changes to Content-Encoding? Summary: Original bug: mod_deflate may compress/decompress content but leave an existing ETag in place. [ various discussion followed ] Yesterday: I committed a fix to /trunk/, assuming it would be uncontroversial. The fix is that any existing ETag should be made a weak ETag if mod_deflate either inflates or deflates the contents. Rationale: a weak ETag promises equivalent but not byte-by-byte identical contents, and that's exactly what you have with mod_deflate. Henrik Nordstrom commented: "Not sufficient. The two versions is not semantically equivalen as one can not be exchanged for the other without breaking the protocol. In the context of If-None-Match the weak comparator is used in HTTP and there a strong ETag is equal to a weak ETag." Further discussion followed. I won't repost it here in full, but since there clearly is an issue, it needs discussing here. Cc: folks subscribed to the bug. -- Nick Kew Application Development with Apache - the Apache Modules Book http://www.apachetutor.org/