Add a check on the existence of __qualname__ (#8642)

Co-authored-by: anci3ntr0ck <hu_shuo@venustech.com.cn>
Co-authored-by: Sydney Runkle <54324534+sydney-runkle@users.noreply.github.com>

pydantic/_internal/_model_construction.py

@@ -334,6 +334,7 @@ def inspect_namespace(  # noqa C901
         elif (
             isinstance(value, type)
             and value.__module__ == namespace['__module__']
+            and '__qualname__' in namespace
             and value.__qualname__.startswith(namespace['__qualname__'])
         ):
             # `value` is a nested type defined in this namespace; don't error

tests/test_create_model.py

@@ -601,3 +601,12 @@ class Y:
     )
     Z = create_model('Z', y=(module.Y, ...))
     assert Z(y={'x': {}}).y is not None
+
+
+def test_type_field_in_the_same_module():
+    class A:
+        pass
+
+    B = create_model('B', a_cls=(type, A))
+    b = B()
+    assert b.a_cls == A