Fix crash in callable check (#2901)

4 files changed, 22 insertions, 1 deletions

diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index ea603452b..d01b830aa 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -299,3 +299,5 @@ contributors:
 
 * Zeb Nicholls: contributor
     - Made W9011 compatible with 'of' syntax in return types
+
+* Martin Vielsmaier: contributor
diff --git a/ChangeLog b/ChangeLog
index 59b18f0ef..93192a473 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,8 @@ What's New in Pylint 2.4.0?
 
 Release date: TBA
 
+* Fix crash happening when parent of called object cannot be determined
+
 * Allow of in `GoogleDocstring.re_multiple_type`
 
 * Added `subprocess-run-check` to handle subrocess.run without explicitly set `check` keyword.
diff --git a/pylint/checkers/typecheck.py b/pylint/checkers/typecheck.py
index d5981ab3b..1b96d5d26 100644
--- a/pylint/checkers/typecheck.py
+++ b/pylint/checkers/typecheck.py
@@ -1051,7 +1051,8 @@ accessed. Python regular expressions are accepted.",
             if isinstance(called, astroid.Instance) and (
                 not has_known_bases(called)
                 or (
-                    isinstance(called.scope(), astroid.ClassDef)
+                    called.parent is not None
+                    and isinstance(called.scope(), astroid.ClassDef)
                     and "__get__" in called.locals
                 )
             ):
diff --git a/pylint/test/unittest_checker_typecheck.py b/pylint/test/unittest_checker_typecheck.py
index 7bce396c5..ba61a7d13 100644
--- a/pylint/test/unittest_checker_typecheck.py
+++ b/pylint/test/unittest_checker_typecheck.py
@@ -332,3 +332,19 @@ class TestTypeChecker(CheckerTestCase):
         )
         with self.assertNoMessages():
             self.checker.visit_call(call)
+
+    def test_unknown_parent(self):
+        """Make sure the callable check does not crash when a node's parent
+        cannot be determined.
+        """
+        call = astroid.extract_node(
+            """
+        def get_num(n):
+            return 2 * n
+        get_num(10)()
+        """
+        )
+        with self.assertAddsMessages(
+            Message("not-callable", node=call, args="get_num(10)")
+        ):
+            self.checker.visit_call(call)