Hi!

We (Autoconf) have a big problem with Zsh 3.0.8.  You know it is
shipped on Darwin as /bin/sh.  But this version does not understand
${1+"$@"} properly.  We use this instead of "$@" to work around a bug
which still exists today in many many constructors' /bin/sh, so we
can't departure from it.

But then, I have no choice than systematically rejecting /bin/sh if it
turns out to be zsh 3.  Unless there is some magic that can make
${1+"$@"} work properly?  Thanks!