--- src/cmd/ksh93/bltins/typeset.c
+++ src/cmd/ksh93/bltins/typeset.c	2014-02-18 15:57:51.077469326 +0000
@@ -549,7 +549,7 @@ static int     setall(char **argv,regist
 	}
 	else if(*shp->prefix==0)
 		shp->prefix = 0;
-	if(*argv[0]=='+')
+	if(*argv && *argv[0]=='+')
 		nvflags |= NV_NOADD;
 	flag &= ~(NV_NOARRAY|NV_NOSCOPE|NV_VARNAME|NV_IDENT|NV_STATIC|NV_COMVAR|NV_IARRAY);
 	if(argv[1])