Subject: bug#17568: 24.4.50; Unknown button type 'help-xref' when do C-x C-s in shell mode

From: Drew Adams <[email-masked]>
Date: Fri, 23 May 2014 14:56:04 -0700 (PDT)

My crystal ball tells me this might represent more collateral damage
from bug #17109.  I say this because I've seen similar breakage
elsewhere, the problem being that existing code expected a buffer
to be in `help-mode' after `with-output-to-temp-buffer'.

HTH.  If not, ignore.