broken MIME parse? also, another MIME error thrown

[Karl Kleinpaste <karl@justresearch.com>]

In p0.48 + last evening's patch to fix `2 b' failing in *Article*...

I got a message off a mailing list which had MIME-Version and
Content-Type headers, including a boundary="..." spec, but then there
were no parts in the message containing that boundary.  The result was 
that the message did not display at all.  Also, not recognizing the
nature of the problem at first, I tried `1 b' to render something I
thought must be hidden, which threw this error:

Signaling: (wrong-type-argument integer-or-marker-p nil)
  gnus-mime-display-alternative(nil nil (#<marker at 1214 in *Article*>) 1)
  (lambda (handles) (gnus-mime-display-alternative (quote nil) nil (quote ...) 1))(nil)
  gnus-article-press-button()
  gnus-article-view-part(1)
  call-interactively(gnus-article-view-part)

Disregarding the error thrown, is this proper behavior in the MIME
context, that the entire content be left unrendered in the absence of
boundaries?

E.g., given source for a message:
	________________

	From: nobody@no.where
	To: karl
	Mime-Version: 1.0
	Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01BE1207.AEDC5960"
	Subject: MIME failure test

	Random junk here.

	In fact, a lot more random garbage here.
	________________

I fed that to "sendmail -t"; the result in Gnus was:
	________________

	X-From-Line: nobody@no.where.jprc.com  Tue Nov 17 17:26:57 1998
	Return-Path: <nobody@no.where.jprc.com>
	Received: (from karl@localhost)
		by beaver.jprc.com (8.8.7/8.8.7) id RAA05548;
		Tue, 17 Nov 1998 17:26:56 -0500
	Date: Tue, 17 Nov 1998 17:26:56 -0500
	From: nobody@no.where.jprc.com
	Message-Id: <199811172226.RAA05548@beaver.jprc.com>
	To: karl@beaver.jprc.com
	Mime-Version: 1.0
	Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01BE1207.AEDC5960"
	Subject: MIME failure test
	Lines: 4
	Xref: beaver.jprc.com mailer-daemon:30887
	
	Random junk here.

	In fact, a lot more random garbage here.
	________________

But it displays as just:
	________________

	From: nobody@no.where.jprc.com
	Subject: MIME failure test
	To: karl@justresearch.com
	X-Sent: 2 minutes, 49 seconds ago

	1.  
	________________