gh-111615: Fix regression in QueueHandler configuration. (GH-111638)

Lib/logging/config.py

@@ -1,4 +1,4 @@
-# Copyright 2001-2022 by Vinay Sajip. All Rights Reserved.
+# Copyright 2001-2023 by Vinay Sajip. All Rights Reserved.
 #
 # Permission to use, copy, modify, and distribute this software and its
 # documentation for any purpose and without fee is hereby granted,
@@ -734,7 +734,7 @@ class DictConfigurator(BaseConfigurator):
             lklass = kwargs['listener']
         else:
             lklass = logging.handlers.QueueListener
-        listener = lklass(q, *kwargs['handlers'], respect_handler_level=rhl)
+        listener = lklass(q, *kwargs.get('handlers', []), respect_handler_level=rhl)
         handler = klass(q)
         handler.listener = listener
         return handler
@@ -776,11 +776,12 @@ class DictConfigurator(BaseConfigurator):
                     raise ValueError('Unable to set target handler %r' % tn) from e
             elif issubclass(klass, logging.handlers.QueueHandler):
                 # Another special case for handler which refers to other handlers
-                if 'handlers' not in config:
-                    raise ValueError('No handlers specified for a QueueHandler')
+                # if 'handlers' not in config:
+                    # raise ValueError('No handlers specified for a QueueHandler')
                 if 'queue' in config:
+                    from multiprocessing.queues import Queue as MPQueue
                     qspec = config['queue']
-                    if not isinstance(qspec, queue.Queue):
+                    if not isinstance(qspec, (queue.Queue, MPQueue)):
                         if isinstance(qspec, str):
                             q = self.resolve(qspec)
                             if not callable(q):
@@ -813,6 +814,7 @@ class DictConfigurator(BaseConfigurator):
                         if not callable(listener):
                             raise TypeError('Invalid listener specifier %r' % lspec)
                         config['listener'] = listener
+                if 'handlers' in config:
                     hlist = []
                     try:
                         for hn in config['handlers']:

Lib/test/test_logging.py

@@ -3922,6 +3922,25 @@ class ConfigDictTest(BaseTest):
         # Logger should be enabled, since explicitly mentioned
         self.assertFalse(logger.disabled)
 
+    def test_111615(self):
+        # See gh-111615
+        import multiprocessing as mp
+
+        config = {
+            'version': 1,
+            'handlers': {
+                'sink': {
+                    'class': 'logging.handlers.QueueHandler',
+                    'queue': mp.get_context('spawn').Queue(),
+                },
+            },
+            'root': {
+                'handlers': ['sink'],
+                'level': 'DEBUG',
+            },
+        }
+        logging.config.dictConfig(config)
+
 class ManagerTest(BaseTest):
     def test_manager_loggerclass(self):
         logged = []

Misc/NEWS.d/next/Library/2023-11-02-10-13-31.gh-issue-111615.3SMixi.rst

@@ -0,0 +1,2 @@
+Fix a regression caused by a fix to gh-93162 whereby you couldn't configure
+a :class:`QueueHandler` without specifying handlers.