lksh also reads $ENV so make sure it doesn’t try this one

dot.mkshrc

@@ -1,5 +1,5 @@
 # $Id$
-# $MirOS: src/bin/mksh/dot.mkshrc,v 1.79 2013/04/05 15:39:52 tg Exp $
+# $MirOS: src/bin/mksh/dot.mkshrc,v 1.80 2013/04/27 18:19:44 tg Exp $
 #-
 # Copyright (c) 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010,
 #		2011, 2012, 2013
@@ -22,6 +22,12 @@
 #-
 # ${ENV:-~/.mkshrc}: mksh initialisation file for interactive shells
 
+# catch non-mksh (including lksh) trying to shell this file
+case $KSH_VERSION in
+*MIRBSD\ KSH*) ;;
+*) return 0 ;;
+esac
+
 PS1='#'; (( USER_ID )) && PS1='$'; [[ ${HOSTNAME:=$(ulimit -c 0; hostname -s \
     2>/dev/null)} = *([	 ]|localhost) ]] && HOSTNAME=$(ulimit -c 0; hostname \
     2>/dev/null); : ${EDITOR:=/bin/ed} ${HOSTNAME:=nil} ${TERM:=vt100}