bin/40393: groupmod -g allowed reusing GID even without -o switch

[reed%reedmedia.net@localhost]

>Number:         40393
>Category:       bin
>Synopsis:       groupmod -g allowed reusing GID even without -o switch
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jan 14 02:10:00 +0000 2009
>Originator:     reed%reedmedia.net@localhost
>Release:        NetBSD 5.0_BETA
>Organization:
  Jeremy C. Reed
>Environment:
        
        
Architecture: x86_64
Machine: amd64
>Description:

$ sudo groupmod -g 20000 school
$ grep :20000: /etc/group 
school:*:20000:
avery:*:20000:

Should have failed since I didn't use -o.

>How-To-Repeat:
        
>Fix:
        

>Unformatted: