Closes issue #18698: ensure importlib.reload() returns the module out of sys.modules.

2 files changed, 19 insertions, 1 deletions

diff --git a/Lib/importlib/__init__.py b/Lib/importlib/__init__.py
index 6732977..69ca9ce 100644
--- a/Lib/importlib/__init__.py
+++ b/Lib/importlib/__init__.py
@@ -118,7 +118,9 @@ def reload(module):
         if parent_name and parent_name not in sys.modules:
             msg = "parent {!r} not in sys.modules"
             raise ImportError(msg.format(parent_name), name=parent_name)
-        return module.__loader__.load_module(name)
+        module.__loader__.load_module(name)
+        # The module may have replaced itself in sys.modules!
+        return sys.modules[module.__name__]
     finally:
         try:
             del _RELOADING[name]
diff --git a/Lib/test/test_importlib/test_api.py b/Lib/test/test_importlib/test_api.py
index 3a28cb7..0c0e851 100644
--- a/Lib/test/test_importlib/test_api.py
+++ b/Lib/test/test_importlib/test_api.py
@@ -162,6 +162,22 @@ class ReloadTests(unittest.TestCase):
                     module = importlib.import_module(mod)
                     importlib.reload(module)
 
+    def test_module_replaced(self):
+        def code():
+            import sys
+            module = type(sys)('top_level')
+            module.spam = 3
+            sys.modules['top_level'] = module
+        mock = util.mock_modules('top_level',
+                                 module_code={'top_level': code})
+        with mock:
+            with util.import_state(meta_path=[mock]):
+                module = importlib.import_module('top_level')
+                reloaded = importlib.reload(module)
+                actual = sys.modules['top_level']
+                self.assertEqual(actual.spam, 3)
+                self.assertEqual(reloaded.spam, 3)
+
 
 class InvalidateCacheTests(unittest.TestCase):