Avoid invoking the current script again when we need

to issue sub-commands, e.g., restart = stop + start.
By calling run_rc_command instead, we provide rc.d
scripts with full control over their configuration
variables.

For an example problem the former approach caused, see
http://lists.freebsd.org/pipermail/freebsd-rc/2005-October/000311.html

Reviewed by:	freebsd-rc
Tested by:	Dirk Engling erdgeist <at> erdgeist.org
MFC after:	2 weeks

etc/rc.subr

@@ -770,8 +770,9 @@ $command $rc_flags $command_args"
 			fi
 			_rc_restart_done=true
 
-			( $0 ${_rc_prefix}stop $rc_extra_args )
-			$0 ${_rc_prefix}start $rc_extra_args
+			# run stop in a subshell to keep variables for start
+			( run_rc_command ${_rc_prefix}stop $rc_extra_args )
+			run_rc_command ${_rc_prefix}start $rc_extra_args
 
 			if [ -n "$_postcmd" ]; then
 				eval $_postcmd $rc_extra_args