Make sure the datatype for the "logger" section type adds a NullHandler if

no other handlers are provided.  This is needed to avoid warnings on stderr
from the logging package.

src/zLOG/datatypes.py

@@ -235,8 +235,12 @@ class LoggerWrapper:
             logger.handlers = []
             logger.propagate = 0
             logger.setLevel(self.level)
-            for handler_factory in self.handler_factories:
-                handler =  handler_factory()
-                logger.addHandler(handler)
+            if self.handler_factories:
+                for handler_factory in self.handler_factories:
+                    handler =  handler_factory()
+                    logger.addHandler(handler)
+            else:
+                from zLOG.LogHandlers import NullHandler
+                logger.addHandler(NullHandler())
             self.resolved = logger
         return self.resolved

src/zLOG/tests/testzLogConfig.py

@@ -19,6 +19,7 @@ import logging
 import unittest
 
 import ZConfig
+import zLOG.LogHandlers
 import zLOG.tests
 
 
@@ -54,7 +55,11 @@ class TestzLOGConfig(unittest.TestCase):
         self.assertEqual(conf.logger.level, logging.INFO)
         logger = conf.logger()
         self.assert_(isinstance(logger, logging.Logger))
-        self.assertEqual(logger.handlers, [])
+        # Make sure there's a NullHandler, since a warning gets
+        # printed if there are no handlers:
+        self.assertEqual(len(logger.handlers), 1)
+        self.assert_(isinstance(logger.handlers[0],
+                                zLOG.LogHandlers.NullHandler))
 
     # XXX need to make sure each loghandler datatype gets exercised.