bin/46226: underscore character ignored at the end of password

[wlsidorenko%gmail.com@localhost]

>Number:         46226
>Category:       bin
>Synopsis:       underscore character ignored at the end of password
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Mar 19 09:20:00 +0000 2012
>Originator:     Vladimir Sidorenko
>Release:        5.1
>Organization:
IMB
>Environment:
NetBSD sidorenko.imb.invention.com 5.1 NetBSD 5.1 (GENERIC) #0: Sun Nov  7 
14:39:56 UTC 2010  
builds%b6.netbsd.org@localhost:/home/builds/ab/netbsd-5-1-RELEASE/i386/201011061943Z-obj/home/builds/ab/netbsd-5-1-RELEASE/src/sys/arch/i386/compile/GENERIC
 i386
>Description:
It seems, that underscore character is ignored at the end of one's password. 
For example if I set a password for user xxx to

1suirrel_

I'm able to do `su xxx' by just typing

1suirrel

And `1suirrel_'  works too. Though when underscore is used at the beginning of 
password it seemingly isn't ignored.

/etc/passwd.conf is default as it came with the base system
>cat /etc/passwd.conf
#       $NetBSD: passwd.conf,v 1.2 2002/04/15 07:48:00 ad Exp $
#
# passwd.conf(5) -
#       password configuration file
#

#default:
#       localcipher = md5
#       ypcipher = old

>How-To-Repeat:
1) set new password for user xxx
xxx>passwd
Old password:
New password: 1suirrel_
Retype new password: 1suirrel_

2) su to user yyy

3) try to su to xxx again and type 1suirrel as password
yyy> whoami
yyy

yyy> su xxx
Password: 1suirrel

xxx>whoami
xxx

>Fix: