chsh overwrites encrypted password

My patch for the NIS shadow password security vulnerability introduced a new bug.
One of my NIS users informed me
that she could not login any more after she had used chsh to change her
login shell. The reason was that in the shadow file, the encrypted
password had been replaced by an 'x'. This happens because in my
patch, file nis-pwd.c, the string "##<username>" is replaced with "x".

I thought that this replacement is necessary to let libc6 search for
the encrypted password in the shadow map. But now I found out that it
is not necessary and that without it everything works fine: logging in,
changing password and changing the shell.

I have attached a new patch that simply lets the password field of the
passwd.byname map alone

ProblemType: Bug
Architecture: amd64
Date: Tue Feb 23 16:17:28 2010
Dependencies:
 libgcc1 1:4.2.4-1ubuntu3
 gcc-4.2-base 4.2.4-1ubuntu3
 libc6 2.7-10ubuntu5
DistroRelease: Ubuntu 8.04
Package: libc6 2.7-10ubuntu5
PackageArchitecture: amd64
ProcEnviron:
 SHELL=/bin/tcsh
 PATH=/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games
 LANG=en_US.UTF-8
SourcePackage: glibc
Uname: Linux 2.6.24-24-generic x86_64