diff -r 07878573dad3 -r 9265805e77d5 components/ksh93/patches/17851169.patch
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/components/ksh93/patches/17851169.patch	Tue Mar 25 10:51:42 2014 +0100
@@ -0,0 +1,32 @@
+http://lists.research.att.com/pipermail/ast-developers/2014q1/003809.html
+---
+--- a/src/cmd/ksh93/sh/subshell.c
++++ b/src/cmd/ksh93/sh/subshell.c
+@@ -234,15 +234,22 @@ Namval_t *sh_assignok(register Namval_t *np,int add)
+ {
+ 	register Namval_t	*mp;
+ 	register struct Link	*lp;
+-	register struct subshell *sp = (struct subshell*)subshell_data;
+-	Shell_t			*shp = sp->shp;
+-	Dt_t			*dp= shp->var_tree;
++	register struct subshell *sp;
++	Shell_t			*shp;
++	Dt_t			*dp;
+ 	Namval_t		*mpnext;
+ 	Namarr_t		*ap;
+ 	int			save;
++
++        sp = (struct subshell*)subshell_data;
++
+ 	/* don't bother with this */
+-	if(!sp->shpwd || np==SH_LEVELNOD || np==L_ARGNOD || np==SH_SUBSCRNOD || np==SH_NAMENOD)
++	if(!sp || !sp->shpwd || np==SH_LEVELNOD || np==L_ARGNOD || np==SH_SUBSCRNOD || np==SH_NAMENOD)
+ 		return(np);
++
++	shp = sp->shp;
++	dp = shp->var_tree;
++
+ 	if((ap=nv_arrayptr(np)) && (mp=nv_opensub(np)))
+ 	{
+ 		shp->last_root = ap->table;
+