Description of problem:
When nscd is running, getservbyport() returns garbage.

With stock /etc/services, it returns spr-itunes (0 port) for any query.  With 0
port removed from /etc/services, it returns NULL for any query.

Version-Release number of selected component (if applicable):
glibc-2.8-3.i686
nscd-2.8-3.i386
setup-2.6.14-1.fc9.noarch

How reproducible:
always

Steps to Reproduce:

Use the following program:

#include <netdb.h>
#include <stdio.h>

int main(int argc, char **argv)
{
	struct servent *s;
	s = getservbyport(htons(atoi(argv[1])), argv[2]);
	if (s)
		printf("%s\n", s->s_name);
	else
		printf("port not found\n");
}


Without nscd everything is fine:

# service nscd stop
Stopping nscd:                                             [  OK  ]
# ./bug 25 tcp
smtp
# ./bug 7425 tcp
port not found


With nscd and 0 port in /etc/services (stock /etc/services from setup package):

# awk '$2 == "0/tcp" {print}' /etc/services
spr-itunes	0/tcp			# Shirt Pocket netTunes
spl-itunes	0/tcp			# Shirt Pocket launchTunes
# service nscd stop
Stopping nscd:                                             [FAILED]
# rm -f /var/db/nscd/*
# service nscd start
Starting nscd:                                             [  OK  ]
# ./bug 25 tcp
spr-itunes
# ./bug 7425 tcp
spr-itunes


With nscd and without 0 port in /etc/services:

# awk '$2 != "0/tcp"' /etc/services > /etc/services.nozero
# cat /etc/services.nozero > /etc/services
# service nscd stop
Stopping nscd:                                             [FAILED]
# rm -f /var/db/nscd/*
# service nscd start
Starting nscd:                                             [  OK  ]
# ./bug 25 tcp
port not found
# ./bug 7425 tcp
port not found