[VM] mail-default-headers requires trailing newline?

[Skip Montanaro]

(I know this isn't a VM question, but it is a mail question, and 
folks here are likely to cross the GNU Emacs/XEmacs chasm from
time-to-time.)

I just noticed that my mail-default-headers variable broke when I
switched from XEmacs 21.x to GNU Emacs 23.x.  XEmacs doesn't
require a trailing newline.  GNU Emacs does.  Is this just another
place where there are annoying differences between the two
dialects, or is there a good reason to prefer one way over the
other?

Thx,

Skip