Rewrite the `hostname mismatch' test as per GvR suggestion.

Don't assume gethostbyaddr()'s primary hostname is the same as
gethostname(), or even that gethostname() can be found in the list of
hosts returned by gethostbyaddr().  We do test for at least one FQDN
in gethostbyaddr().

Lib/test/test_socket.py

@@ -12,6 +12,7 @@ from test_support import verbose
 import socket
 import os
 import time
+import string
 
 def missing_ok(str):
     try:
@@ -67,14 +68,19 @@ for optional in ("AF_UNIX",
 hostname = socket.gethostname()
 ip = socket.gethostbyname(hostname)
 hname, aliases, ipaddrs = socket.gethostbyaddr(ip)
+all_host_names = [hname] + aliases
 
 if verbose:
     print hostname
     print ip
     print hname, aliases, ipaddrs
+    print all_host_names
 
-if hostname <> hname:
-    print 'hostname mismatch'
+for name in all_host_names:
+    if string.find(name, '.'):
+	break
+else:
+    print 'FQDN not found'
 
 print socket.getservbyname('telnet', 'tcp')
 try: