[ "x$@" != "x" ] || { usage 1>&2; exit 1; }
# Authorize the user.
-xauth extract - $DISPLAY | sudo -u "$USERNAME" xauth merge -
+# Use "sudo -H" to cover the case when env_keep+="HOME" is set in /etc/sudoers
+xauth extract - $DISPLAY | sudo -H -u "$USERNAME" xauth merge -
# Execute the command.
# NOTE: -i or -s can be passed in order to open a shell