sh: Exempt $@ and $* from set -u

This seems more useful and will likely be in the next POSIX standard.

Also document more precisely in the man page what set -u does (note that
$@, $* and $! are the only special parameters that can ever be unset, all
the others are always set, although they may be empty).

1 files changed, 12 insertions, 0 deletions

diff --git a/tools/regression/bin/sh/expansion/set-u2.0 b/tools/regression/bin/sh/expansion/set-u2.0
new file mode 100644
index 0000000..f81aa62
--- /dev/null
+++ b/tools/regression/bin/sh/expansion/set-u2.0
@@ -0,0 +1,12 @@
+# $FreeBSD$
+
+set -u
+: $* $@ "$@" "$*"
+set -- x
+: $* $@ "$@" "$*"
+shift $#
+: $* $@ "$@" "$*"
+set -- y
+set --
+: $* $@ "$@" "$*"
+exit 0