Re: Autoconf 2.60?

[Paul Eggert]

Ludovic Courtès <address@hidden> writes:

> http://lists.gnu.org/archive/html/bug-autoconf/2004-06/msg00019.html
> ...
> However, Tru64's, IRIX' and HPUX' /bin/sh really _stop_ the script.
> In other words, the following script prints "hello" when /bin/sh is
> Bash, and doesn't otherwise:
>
>   #!/bin/sh
>   ENV=sdf
>   readonly ENV
>   unset ENV
>   echo "hello"

OK, but the referenced patch doesn't do that.  It does something like
this instead.  Why is this a problem with those other shells?

#!/bin/sh
ENV=sdf
readonly ENV
as_unset=unset
for as_var in ENV MAIL MAILPATH
do ($as_unset $as_var) >/dev/null 2>&1 && $as_unset $as_var
done
echo "hello"