diff -up ksh-20100621/src/cmd/ksh93/sh/name.c.oopfix ksh-20100621/src/cmd/ksh93/sh/name.c
--- ksh-20100621/src/cmd/ksh93/sh/name.c.oopfix	2010-05-24 20:32:32.000000000 +0200
+++ ksh-20100621/src/cmd/ksh93/sh/name.c	2012-03-02 13:57:35.630402636 +0100
@@ -362,6 +362,8 @@ void nv_setlist(register struct argnod *
 					}
 				}
 				np = nv_open(cp,shp->var_tree,flag|NV_ASSIGN);
+			        if(nv_isattr(np,NV_RDONLY) && np->nvfun && !(flags&NV_RDONLY))
+				        errormsg(SH_DICT,ERROR_exit(1),e_readonly, nv_name(np));
 				if(typ && !array  && (nv_isnull(np) || nv_isarray(np)))
 					nv_settype(np,typ,0);
 				if((flags&NV_STATIC) && !nv_isattr(np,NV_EXPORT) && !nv_isnull(np))