From c99a22a6bf4468a454ad950f634628e019e04a30 Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Sun, 17 Apr 2022 21:20:39 -0700
Subject: [PATCH] Fix type context for cast()

---
 mypy/checkexpr.py                  | 2 +-
 test-data/unit/check-warnings.test | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
index 7383a2b69610..974a2144cd18 100644
--- a/mypy/checkexpr.py
+++ b/mypy/checkexpr.py
@@ -3131,7 +3131,7 @@ def visit_enum_index_expr(
 
     def visit_cast_expr(self, expr: CastExpr) -> Type:
         """Type check a cast expression."""
-        source_type = self.accept(expr.expr, type_context=AnyType(TypeOfAny.special_form),
+        source_type = self.accept(expr.expr, type_context=self.type_context[-1],
                                   allow_none_return=True, always_allow_any=True)
         target_type = expr.type
         options = self.chk.options
diff --git a/test-data/unit/check-warnings.test b/test-data/unit/check-warnings.test
index 10c7968be475..398b3463a284 100644
--- a/test-data/unit/check-warnings.test
+++ b/test-data/unit/check-warnings.test
@@ -42,6 +42,15 @@ a: Any
 b = cast(Any, a)
 [builtins fixtures/list.pyi]
 
+[case testRedundantCastTypeContext]
+# flags: --warn-redundant-casts
+from typing import List, cast
+
+class A: ...
+class B(A): ...
+
+a: List[A] = cast(List[A], [B()])  # E: Redundant cast to "List[A]"
+
 -- Unused 'type: ignore' comments
 -- ------------------------------