Fix crash on inference of __dict__.items() of an imported module (#1367)

Author: DanielNoord

ChangeLog

@@ -31,6 +31,11 @@ Release date: TBA
   Closes #1282
   Ref #1103
 
+* Fixed crash when trying to infer ``items()`` on the ``__dict__``
+  attribute of an imported module.
+
+  Closes #1085
+
 What's New in astroid 2.9.4?
 ============================
 Release date: TBA

astroid/inference.py

@@ -317,6 +317,8 @@ def infer_attribute(self, context=None):
 
         if not context:
             context = InferenceContext()
+        else:
+            context = copy_context(context)
 
         old_boundnode = context.boundnode
         try:

tests/testdata/python3/data/module_dict_items_call/models.py

@@ -0,0 +1,5 @@
+import re
+
+
+class MyModel:
+    class_attribute = 1

tests/testdata/python3/data/module_dict_items_call/test.py

@@ -0,0 +1,7 @@
+import models
+
+
+def func():
+    for _, value in models.__dict__.items():
+        if isinstance(value, type):
+            value.class_attribute += 1

tests/unittest_inference.py

@@ -48,6 +48,7 @@
 import unittest
 from abc import ABCMeta
 from functools import partial
+from pathlib import Path
 from typing import Any, Callable, Dict, List, Tuple, Union
 from unittest.mock import patch
 
@@ -88,6 +89,7 @@ def get_node_of_class(start_from: nodes.FunctionDef, klass: type) -> nodes.Attri
 
 EXC_MODULE = "builtins"
 BOOL_SPECIAL_METHOD = "__bool__"
+DATA_DIR = Path(__file__).parent / "testdata" / "python3" / "data"
 
 
 class InferenceUtilsTest(unittest.TestCase):
@@ -1732,8 +1734,7 @@ def __init__(self):
         """
         ast = extract_node(code, __name__)
         expr = ast.func.expr
-        with pytest.raises(InferenceError):
-            next(expr.infer())
+        self.assertIs(next(expr.infer()), util.Uninferable)
 
     def test_tuple_builtin_inference(self) -> None:
         code = """
@@ -6584,5 +6585,13 @@ def test_relative_imports_init_package() -> None:
     )
 
 
+def test_inference_of_items_on_module_dict() -> None:
+    """Crash test for the inference of items() on a module's dict attribute.
+
+    Originally reported in https://github.com/PyCQA/astroid/issues/1085
+    """
+    builder.file_build(str(DATA_DIR / "module_dict_items_call" / "test.py"), "models")
+
+
 if __name__ == "__main__":
     unittest.main()