TECHNICAL INFORMATION DOCUMENT

TITLE:  TF2085 - csh setenv patch
DATE:  12OCT95
README FOR:  TF2085
PRODUCT and VERSION:

UnixWare 2.01

Installation Instructions:  

DATATYPE: datastream

1.  Download the tf2085.Z and tf2085.txt files to the /tmp directory
    on your machine.

2.  Read the release notes contained in this file and follow the 
    instuctions to add the package to your system.

3.  Now become root, uncompress the file and add the package to your 
    system using the following commands:

        $ su
        # uncompress /tmp/tf2085.Z
        # pkgadd -d /tmp/tf2085

ENGINEERING RELEASE NOTES
-------------------------

Title
-----

PTF2085 - csh setenv patch

Product And Version
-------------------

UnixWare 2.01, UnixWare 2.02

Abstract
--------

The csh command has a timing problem when it forks processes; a race
condition exists when a child process changes its process group ID.

Symptom
--------

When using csh interactively, a pipeline (e.g. setenv | pg) may hang;
you may or may not get the message, "Stopped (tty output)".


SOLUTION SPECIFICS
------------------

General Description.
-------------------

In sh.proc.c,  added a handshake between parent and child processes
if the child is going to be changing its process group.  This will
prevent the race condition whereby the group leader exits before the
child has had a chance to join the group.


New Features.
------------

None

Software Notes and Recommendations.
----------------------------------

This PTF can be installed on UnixWare 2.01 or 2.02 systems which have the
Advanced Commands (cmds) package installed.  If the fix is installed on
UnixWare 2.01, and the system is then upgraded to 2.02, the fix does NOT
need to be reinstalled.

Testing of the modified software contained in this package has been
conducted only to the extent necessary to confirm that it resolves the
problem(s) stated above ("Symptom").  Such testing consists of
recreating the problem conditions and verifying that the problem no 
longer occurs.  No other testing of this software has been done.

Hardware Notes and Recommendations.
----------------------------------

This PTF is targeted for the i386, i486 and Pentium CPU's.