gh-152298: Cover module attribute lazy reification

Author: 1sgtpepper

Lib/test/test_lazy_import/__init__.py

@@ -544,6 +544,36 @@ def custom_import(name, globals=None, locals=None, fromlist=None,
         """)
         assert_python_ok("-c", code)
 
+    @support.requires_subprocess()
+    def test_module_attribute_reification_does_not_clobber_changed_global(self):
+        code = textwrap.dedent("""
+            import builtins
+            import sys
+            import types
+
+            real_import = builtins.__import__
+            module = sys.modules[__name__]
+
+            lazy import target_module as target
+
+            def custom_import(name, globals=None, locals=None, fromlist=None,
+                              level=0):
+                if name == "target_module":
+                    module.__dict__["target"] = "user value"
+                    resolved = types.ModuleType(name)
+                    resolved.VALUE = "resolved"
+                    return resolved
+                return real_import(name, globals, locals, fromlist, level)
+
+            builtins.__import__ = custom_import
+            try:
+                assert module.target.VALUE == "resolved"
+                assert module.__dict__["target"] == "user value"
+            finally:
+                builtins.__import__ = real_import
+        """)
+        assert_python_ok("-c", code)
+
 
 class SyntaxRestrictionTests(LazyImportTestCase):
     """Tests for syntax restrictions on lazy imports."""