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

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]

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):
 

Misc/NEWS

@@ -203,6 +203,8 @@ Core and Builtins
 
 - Issue #17867: Raise an ImportError if __import__ is not found in __builtins__.
 
+- Issue #18698: Ensure importlib.reload() returns the module out of sys.modules.
+
 - Issue #17857: Prevent build failures with pre-3.5.0 versions of sqlite3,
   such as was shipped with Centos 5 and Mac OS X 10.4.