Bug 1116072

Sorry about that ... apparently hit "return" at an inopportune time.

Description of problem:

When calling a function inside of command substitution and the function both opens and closes the file descriptor "3", the output generated by the function is not returned as a result of the command substitution.

Sample code:
------------------------------------------------------------------------------
#!/bin/ksh

tmpfile=/tmp/bug.$$

function get_value
{
    #
    # Bug is not exhibited for empty files or files like
    # /etc/passwd, so create a file here.
    #
    ls > $tmpfile

    #
    # Bug is not exhibited if choosing a higher-numbered file
    # descriptor (e.g., 4).  However, since we don't know if we'll
    # be called from within command substitutions, or the number of
    # levels of command substitution, this is not a general solution.
    #
    exec 3< $tmpfile

    #
    # My actual program performs some "read -u3" statments, but that
    # is not necessary to exercise bug.
    #

    if [[ $1 = close_fd ]]
    then
        exec 3<&-
    fi

    print return-value
}


value=$(get_value close_fd)
print ${value:-error: no return value}
rm $tmpfile

value=$(get_value noclose_fd)
print ${value:-no value}
rm $tmpfile

exit 0
------------------------------------------------------------------------------


Version-Release number of selected component (if applicable):
This appears to have been introduced sometime between ast-ksh.2012-01-01 (works correctly) and ast-ksh.2012-02-02 (exhibits bug).  The bug persists in ast-ksh.2012-08-01, the last stable version on the AT&T Website at this time.  The bug is still present in ast-ksh.2013-10-10 but is fixed in ast-ksh.2014-06-25 (these are the only two releases after ast-ksh.2012-08-01 that I can find).

How reproducible:
Always.

Steps to Reproduce:
1.  Run sample code above
2.  There is no #2.
3.

Actual results:
error: no return value
return-value

Expected results:
return-value
return-value

Additional info:

reproducible

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-1450.html