Comment 4 for bug 247330

This currently breaks -x, since "-x foo bar" ends up running /bin/sh -c foo bar.

We can either quote it so it runs sh -c "foo bar" and so -x foo \&\& bar will work as -e "foo && bar", or we can pass it directly to exec if there's more than one argument (so -x "foo && bar" will Just Work, but -x foo \&\& bar will run /path/to/foo "&&" "bar").

The latter seems like a reasonable compromise.