Split run in 2 tests su to root and su to user.

tests/su/01/su_user.test

@@ -0,0 +1,44 @@
+#!/bin/sh
+
+set -e
+
+cd $(dirname $0)
+
+# Rational:
+# Test that su can be used to switch to root and to a normal account
+
+# no testsuite password
+# root password: rootF00barbaz
+# myuser password: myuserF00barbaz
+
+save()
+{
+	[ ! -d tmp ] && mkdir tmp
+	for i in passwd group shadow gshadow
+	do
+		[ -f /etc/$i  ] && cp /etc/$i  tmp/$i
+	done
+
+	true
+}
+
+restore()
+{
+	for i in passwd group shadow gshadow
+	do
+		[ -f tmp/$i  ] && cp tmp/$i  /etc/$i  && rm tmp/$i
+	done
+	rmdir tmp
+}
+
+save
+
+# restore the files on exit
+trap 'restore' 0
+
+cp data/{passwd,shadow,group,gshadow} /etc/
+
+./run_su root rootF00barbaz '# '
+
+./run_su myuser myuserF00barbaz '$ '
+