bin/45123: sort(1) -k field descriptions should take +[0-9]

[jkoshy%users.sf.net@localhost]

>Number:         45123
>Category:       bin
>Synopsis:       'sort -k +3' should work.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 07 12:35:00 +0000 2011
>Originator:     Joseph Koshy
>Release:        NetBSD 5.0.0_PATCH
>Organization:
elftoolchain (http://elftoolchain.sourceforge.net/)
>Environment:
        
        
System: NetBSD foobar 5.0.0_PATCH NetBSD 5.0.0_PATCH (XEN3_DOMU) #4: Tue Sep 8 
10:25:45 IST 2009 
root@pub:/home/build/src-5.0/sys/arch/amd64/compile/obj/XEN3_DOMU amd64
Architecture: x86_64
Machine: amd64
>Description:
        sort(1) should take + prefix to -k feild
>How-To-Repeat:
        $ sort -k +3
        sort: field numbers must be positive
        $
>Fix: