diff -up ksh-20120801/src/cmd/ksh93/sh/xec.c.hokaido ksh-20120801/src/cmd/ksh93/sh/xec.c

--- ksh-20120801/src/cmd/ksh93/sh/xec.c.hokaido	2014-09-18 14:41:57.696756230 +0200

+++ ksh-20120801/src/cmd/ksh93/sh/xec.c	2014-09-18 14:43:55.439205247 +0200

@@ -1633,12 +1633,20 @@ int sh_exec(register const Shnode_t *t,

 #endif /* SHOPT_COSHELL */

 			if(shp->subshell)

 			{

+				int comsubsave = shp->comsub;

+				if(comsubsave==1)

+					shp->comsub = 2;

 				sh_subtmpfile(shp);

+				shp->comsub = comsubsave;

+				if(shp->comsub==1 && (!(shp->fdstatus[1]&IONOSEEK)))

+					unpipe = iousepipe(shp);

+

 				if((type&(FAMP|TFORK))==(FAMP|TFORK))

 				{

 					if(shp->comsub && !(shp->fdstatus[1]&IONOSEEK))

 					{

-						unpipe = iousepipe(shp);

+						if (!unpipe)

+							unpipe = iousepipe(shp);

 						sh_subfork();

 					}

 				}

@@ -2107,7 +2115,11 @@ int sh_exec(register const Shnode_t *t,

 			job.curjobid = 0;

 			if(shp->subshell)

 			{

+				int comsubsave = shp->comsub;

+				if(comsubsave==1)

+					shp->comsub = 2;

 				sh_subtmpfile(shp);

+				shp->comsub = comsubsave;

 				if(shp->comsub==1 && !(shp->fdstatus[1]&IONOSEEK))

 					iousepipe(shp);

 			}