[ksh93-integration-discuss] command substitution, exec, and stdout redirection cause allocation loop

[David Powell]

   Hi guys,

   The following one-liner (including back ticks) causes ksh93 to spin
   out of control consuming all memory at a *very* rapid pace:

     `exec program > file`

   If "file" is a real file (as opposed to /dev/null), the file will
   also grow without bound.  "program" need not exist, i.e.

     `exec > file`

   has the same result.  Using $() instead of `` also has the same
   effect.

   This works fine under all other bourne-compatible shells.

   (I've filed this as bug 6687139.)

   Dave