Re: _AC_CACHE_DUMP simplified

[Eric Blake]

>   what would you say about this simplification of _AC_CACHE_DUMP?
> 

+  case `(ac_space=' '; set | grep ^ac_space) 2>&1` in

Don't you have to quote leading ^ in portable shell?  As in

case `(ac_space=' '; set | grep '^ac_space') 2>&1` in

I searched autoconf.texi, but did not find a definitive answer to
my question (it did point out that ^ is not portable in filenames,
and that leading ^ in expr regex is not portable, but did not
really mention whether bare ^ in shells should be avoided), so
maybe I'm just propagating an urban legend.

-- 
Eric Blake