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/
|