From 9a8c171ed81c0c9510386f7a0451682167021d02 Mon Sep 17 00:00:00 2001
From: Ivan Levkivskyi <levkivskyi@gmail.com>
Date: Fri, 20 Jan 2023 16:54:22 +0000
Subject: [PATCH] Fix false positive on generic base class with six (#14478)

Fixes #14475

The fix is straightforward. We need to use the "guarded accept" at this
stage, similar to e.g. `clean_up_bases_and_infer_type_variables()`.
---
 mypy/semanal.py                   |  2 +-
 test-data/unit/check-classes.test | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/mypy/semanal.py b/mypy/semanal.py
index acc485a609e0..176a9e4053a8 100644
--- a/mypy/semanal.py
+++ b/mypy/semanal.py
@@ -2181,7 +2181,7 @@ def infer_metaclass_and_bases_from_compat_helpers(self, defn: ClassDef) -> None:
         if len(defn.base_type_exprs) == 1:
             base_expr = defn.base_type_exprs[0]
             if isinstance(base_expr, CallExpr) and isinstance(base_expr.callee, RefExpr):
-                base_expr.accept(self)
+                self.analyze_type_expr(base_expr)
                 if (
                     base_expr.callee.fullname
                     in {
diff --git a/test-data/unit/check-classes.test b/test-data/unit/check-classes.test
index fce1aa1768f9..9a38d8f344f7 100644
--- a/test-data/unit/check-classes.test
+++ b/test-data/unit/check-classes.test
@@ -5293,6 +5293,19 @@ class F(six.with_metaclass(t.M)): pass
 class G: pass
 [builtins fixtures/tuple.pyi]
 
+[case testSixMetaclassGenericBase]
+import six
+import abc
+from typing import TypeVar, Generic
+
+T = TypeVar("T")
+
+class C(six.with_metaclass(abc.ABCMeta, Generic[T])):
+    pass
+class D(six.with_metaclass(abc.ABCMeta, C[T])):
+    pass
+[builtins fixtures/tuple.pyi]
+
 -- Special support for future.utils
 -- --------------------------------