get_server_name requires an IP, passing empty is invalid

2 files changed, 6 insertions, 11 deletions

diff --git a/waitress/server.py b/waitress/server.py
index 7175c64..22bcae7 100644
--- a/waitress/server.py
+++ b/waitress/server.py
@@ -193,15 +193,11 @@ class BaseWSGIServer(wasyncore.dispatcher, object):
 
     def get_server_name(self, ip):
         """Given an IP or hostname, try to determine the server name."""
-        if ip:
-            server_name = str(ip)
-        else:
-            server_name = str(self.socketmod.gethostname())
-
-        # Convert to a host name if necessary.
-        for c in server_name:
-            if c != '.' and not c.isdigit():
-                return server_name
+
+        if not ip:
+            raise ValueError('Requires an IP to get the server name')
+
+        server_name = str(ip)
         try:
             if server_name == '0.0.0.0' or server_name == '::':
                 return 'localhost'
diff --git a/waitress/tests/test_server.py b/waitress/tests/test_server.py
index 76eade5..27285fe 100644
--- a/waitress/tests/test_server.py
+++ b/waitress/tests/test_server.py
@@ -74,8 +74,7 @@ class TestWSGIServer(unittest.TestCase):
 
     def test_get_server_name_empty(self):
         inst = self._makeOneWithMap(_start=False)
-        result = inst.get_server_name('')
-        self.assertTrue(result)
+        self.assertRaises(ValueError, inst.get_server_name, '')
 
     def test_get_server_name_with_ip(self):
         inst = self._makeOneWithMap(_start=False)