MUST fix Content-Length?

[mnot@…]

When talking about a Content-Length header field with multiple

identical values, Part 1 Section 3.3.2 of HTTPbis says:

the recipient MUST either reject the message as invalid or replace the duplicated field-values with a single valid Content-Length field containing that decimal value prior to determining the message body length.

It is not clear whether "recipient MUST replace" (a requirement on the recipient) also implies that "a sender MUST replace [...] when forwarding the message" (a requirement on the sender). This issue has been raised on 2011/11/28, but the discussion diverged, and I could not tell whether there was a consensus on what the correct interpretation is.

Please decide whether a proxy MUST "fix" such Content-Length headers when forwarding the message and adjust the above text to clarify one way or another.

[mnot@…]

Proposal from list:

recipient MUST either reject the message as invalid or replace the duplicated field-values with a single valid Content-Length field containing that decimal value prior to determining the message body length or forwarding the message.

[julian.reschke@…]

From [2319]:

intermediaries need to fix C-L too (see #483)