I just got 1.5.21 compiled on my Red Hat Enterprise Linux 5.5 system and
noticed that the behavior of auto_view has changed (for me). In my
.mailcap, I have two text/html entries. The first is to launch my
browser (via Gary Johnson's old "browser launcher from mutt script"),
and the second entry is to run elinks.
In 1.5.20 while I was in the Attachments page, my browser was used. But
in 1.5.21 elinks is used. Furthermore, if I comment out the elinks line
in the .mailcap file, mutt launches /usr/bin/htmlview (which I don't
have specified anywhere).