Add regression test for 'usermod -rG' -- it should not add users to groups they did not previously belong to

tests/usertools/62_usermod_remove_supplementary_groups/usermod.test

@@ -0,0 +1,43 @@
+#!/bin/sh
+
+set -e
+
+cd $(dirname $0)
+
+. ../../common/config.sh
+. ../../common/log.sh
+
+log_start "$0" "usermod can remove users from supplementary groups"
+
+save_config
+
+# restore the files on exit
+trap 'log_status "$0" "FAILURE"; restore_config' 0
+
+change_config
+
+echo -n "Remove user foo from the 'floppy' group (usermod -rG \"floppy\" foo)..."
+usermod -rG "floppy" foo
+echo "OK"
+
+echo -n "Remove user foo from the 'fax' group (usermod -rG \"fax\" foo)..."
+usermod -rG "fax" foo
+echo "OK"
+
+echo -n "Check the passwd file..."
+../../common/compare_file.pl config/etc/passwd /etc/passwd
+echo "OK"
+echo -n "Check the group file..."
+../../common/compare_file.pl data/group /etc/group
+echo "OK"
+echo -n "Check the shadow file..."
+../../common/compare_file.pl config/etc/shadow /etc/shadow
+echo "OK"
+echo -n "Check the gshadow file..."
+../../common/compare_file.pl data/gshadow /etc/gshadow
+echo "OK"
+
+log_status "$0" "SUCCESS"
+restore_config
+trap '' 0
+