Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!cwjcc!ukma!xanth!talos!kjones
From: kjones@talos.uucp (Kyle Jones)
Newsgroups: comp.emacs
Subject: Re: Problem with buffer object life in GNU Emacs Lisp
Message-ID: <1989Aug7.152011.10962@talos.uucp>
Date: 7 Aug 89 15:20:11 GMT
References: <1414@novavax.UUCP>
Reply-To: kjones%talos.uucp@uunet.uu.net
Lines: 17

Bob Weiner writes:
 > If you do something like:
 > 
 > (setq rmail-summary-buffer (get-buffer "RMAIL-summary"))
 > 
 > and then kill the actual summary buffer, rmail-summary-buffer will now
 > reference a 'killed buffer' object.  Typical code uses get-buffer to
 > check if such a buffer exists, if it does not, get-buffer usually returns
 > nil.  The global reference rmail-summary-buffer prevents the object from
 > being garbage collected so (get-buffer "RMAIL-summary") still returns a
 > non-nil value and your conditional code fails.
 > [...]
 > This is all based on GNU Emacs 18.52.  Thanks for any help.

I tried this under GNU Emacs 18.52 here and get-buffer returned nil.
Could you have confused get-buffer with bufferp?  The latter will return
non-nil even if it's argument is a killed buffer.