Fix test for socket.getfqdn() to also include the name returned by

socket.gethostname() in the check for a valid return.

Also clarified docs (official and docstring) that the value from gethostname()
is returned if gethostbyaddr() doesn't do the job.

Doc/lib/libsocket.tex

@@ -202,8 +202,8 @@ If \var{name} is omitted or empty, it is interpreted as the local
 host.  To find the fully qualified name, the hostname returned by
 \function{gethostbyaddr()} is checked, then aliases for the host, if
 available.  The first name which includes a period is selected.  In
-case no fully qualified domain name is available, the hostname is
-returned.
+case no fully qualified domain name is available, the hostname as
+returned by \function{gethostname()} is returned.
 \versionadded{2.0}
 \end{funcdesc}
 

Lib/socket.py

@@ -102,7 +102,7 @@ def getfqdn(name=''):
 
     First the hostname returned by gethostbyaddr() is checked, then
     possibly existing aliases. In case no FQDN is available, hostname
-    is returned.
+    from gethostname() is returned.
     """
     name = name.strip()
     if not name or name == '0.0.0.0':

Lib/test/test_socket.py

@@ -267,7 +267,7 @@ class GeneralModuleTests(unittest.TestCase):
         except socket.error:
             # Probably a similar problem as above; skip this test
             return
-        all_host_names = [hname] + aliases
+        all_host_names = [hostname, hname] + aliases
         fqhn = socket.getfqdn()
         if not fqhn in all_host_names:
             self.fail("Error testing host resolution mechanisms.")