bin/154983: head returns EXIT_SUCCESS upon EOF

[Bjartur Thorlacius]

>Number:         154983
>Category:       bin
>Synopsis:       head returns EXIT_SUCCESS upon EOF
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Feb 23 19:00:19 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Bjartur Thorlacius
>Release:        Darwin 8.11.1
>Organization:
>Environment:
Darwin sophie.lan 8.11.1 Darwin Kernel Version 8.11.1: Wed Oct 10 18:23:28 PDT 2007; root:xnu-792.25.20~1/RELEASE_I386 i386 i386
>Description:
$(head -n $n) returns EXIT_SUCCESS upon premature end of file.

$(head -n $n) should only ever return EXIT_SUCCESS when $n lines have successfully been read to stdout.

P.S. Also affects GNU head.
>How-To-Repeat:
echo|
head -n2 &&
echo bug
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: