Adaptive fill in message-mode is weird

[Chris Brierley <brierley@pobox.com>]

Hi all,

I'm not really sure if this is really a pgnus question (because
of message-mode), or a general adaptive-fill-mode question, so I
figured I'd start here first.

I use the following attribution style:

---+ John Doe <jdoe@fard.com> wrote:
   | 
   | Some stuff that John wrote.
   | 
   | More stuff that John wrote.  Blah, blah, blah, blah, blah,
   | blah, blah, blah, blah, blah, blah, blah, blah, blah, blah, blah,
   | blah, blah, blah, blah, blah, blah, blah, blah, blah, blah,
   | blah, blah.

Now, my understanding of adaptive-fill-mode is pretty tenous, but
here's the deal.  If I leave my draft in message-mode, put point
on the first line of text that John wrote (   | Some ...) and hit
M-q, all of the text is filled as if it was one giant paragraph
of normal text.  However, if I put the draft in mail-mode and do
the same thing, the message is filled appropriately.

Now, this makes sense to me, because investigating the values of
adaptive-fill-first-line-regexp and adaptive-fill-regexp shows
that they are different in each mode:

message-mode:
adaptive-fill-first-line-regexp's value is 
"[ 	]*[-a-z0-9A-Z]*\\(>[ 	]*\\)+[ 	]*\\|\\`[ 	]*\\'"
adaptive-fill-regexp's value is 
"[ 	]*[-a-z0-9A-Z]*\\(>[ 	]*\\)+[ 	]*\\|[ 	]*\\([-|#;>*]+ *\\|(?[0-9]+[.)] *\\)*"

mail-mode:
adaptive-fill-first-line-regexp's value is 
"\\`[ 	]*\\'\\|[ 	]*[-a-z0-9A-Z]*>+[ 	]*"
adaptive-fill-regexp's value is 
"[ 	]*\\([-|#;>*]+ *\\|(?[0-9]+[.)] *\\)+\\|[ 	]*[-a-z0-9A-Z]*>+[ 	]*\\|[ 	]*"

But, the wierd thing is that if I put the draft in message-mode
and *change* adaptive-fill-first-line-regexp and
adaptive-fill-regexp to be the same strings as mail-mode, filling
still *doesn't* work right.  It works the same way it did with
default message-mode values for those variables.

So, this has me completely flummoxed.  How can it be that if I
make those variables the same as in mail-mode, filling still
works differently.

Anyone have any ideas on why this isn't working for me?  Or,
perhaps does anyone have adaptive-fill regexp's that will fill my
example properly?

Thanks very much!