Comment 6 for bug 33505

Thanks for this additional feedback and sorry for my late reply.

I looked at the code and rfc2616 again and will attach a patch that may fix the problem. Testing is welcome, I'm happy to build a test-version of apt for you and put it on people.ubuntu.com.

It will always set Cache-Control: max-age=0 for indexfiles. rfc2616 is clear what this means:
"""
The request includes "max-age=0" cache-control directive, which forces each cache along the path to the origin server to revalidate its own entry, if any, with the next cache or server.
"""

I have to admit that I'm puzzled that Acquire::http::No-Cache=True dosn't work (on the first run). The rfc is pretty clear here:
"""
The request includes a "no-cache" cache-control directive or, for compatibility with HTTP/1.0 clients, "Pragma: no-cache". Field names MUST NOT be included with the no-cache directive in a request. The server MUST NOT use a cached copy when responding to such a request.
"""

Could you please make a dump (with -o Debug::Acquire::http=true) of the first and second run? And attach it here?

Thanks,
 Michael