I have to agree with Mark on essentially all points, and with Neil on
most of them.
In particular, I already had a discussion with Nathaniel to the effect
that the Content-Size: field has to be interpreted as commentary, or at
best as a hint, since the encapsulation delimiters must continue to
represent the truth about the delimiters in the messages. That is,
there can't be two sources of truth in a message, since it's then
undefined what happens if they disagree. Worse, if they disagree, two
different agents will use one source as truth, and will never check the
other source (too much work); if the representations-of-truth disagree
(as they will in practice), then the two agents will both think they're
doing perfectly correct things, yet they can't both be right.
Thus, Content-Size must be viewed as commentary or hint, and truth must
reside in the encapsulation boundaries.
Craig