diff -up ksh-20100621/src/cmd/ksh93/sh/io.c.dontstop ksh-20100621/src/cmd/ksh93/sh/io.c
--- ksh-20100621/src/cmd/ksh93/sh/io.c.dontstop	2011-12-06 14:45:32.000000000 +0100
+++ ksh-20100621/src/cmd/ksh93/sh/io.c	2011-12-06 14:46:06.854854711 +0100
@@ -1123,7 +1123,7 @@ int	sh_redirect(Shell_t *shp,struct iono
 						message = e_file;
 						goto fail;
 					}
-					if(shp->subshell && dupfd==1)
+					if(shp->subshell && dupfd==1 && (sfset(sfstdout,0,0)&SF_STRING))
 					{
 						if(sfset(sfstdout,0,0)&SF_STRING)
 							sh_subtmpfile(shp);