From 101b4672801deda378e41efe99f4c94de4dca05b Mon Sep 17 00:00:00 2001
From: JTCRicardo <jtcricardos@gmail.com>
Date: Fri, 3 Oct 2025 21:46:22 -0400
Subject: [PATCH 1/2] Make enums idempotent

---
 mypy/checkexpr.py                     |  9 ++++++++-
 test-data/unit/check-expressions.test | 13 +++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
index 73282c94be4e..166456e5d35e 100644
--- a/mypy/checkexpr.py
+++ b/mypy/checkexpr.py
@@ -627,7 +627,14 @@ def visit_call_expr_inner(self, e: CallExpr, allow_none_return: bool = False) ->
                 for p in self.chk.options.untyped_calls_exclude
             ):
                 self.msg.untyped_function_call(callee_type, e)
-
+        if isinstance(callee_type, Instance) and callee_type.type.has_base("enum.Enum"):
+            if e.args:
+                arg_type = get_proper_type(self.accept(e.args[0]))
+                if (
+                    isinstance(arg_type, LiteralType)
+                    and arg_type.fallback.type == callee_type.type
+                ):
+                    return arg_type
         ret_type = self.check_call_expr_with_callee_type(
             callee_type, e, fullname, object_type, member
         )
diff --git a/test-data/unit/check-expressions.test b/test-data/unit/check-expressions.test
index ea6eac9a39b3..7f3696e5eda0 100644
--- a/test-data/unit/check-expressions.test
+++ b/test-data/unit/check-expressions.test
@@ -2492,3 +2492,16 @@ x + T  # E: Unsupported left operand type for + ("int")
 T()  # E: "TypeVar" not callable
 [builtins fixtures/tuple.pyi]
 [typing fixtures/typing-full.pyi]
+
+[case testEnumIdempotency]
+[builtins fixtures/tuple.pyi]
+from enum import Enum
+
+class Color(Enum):
+    RED = 1
+    BLUE = 2
+
+def f() -> Color:
+    return Color(Color.RED)
+
+[out]
\ No newline at end of file

From 2524a0e49adc86b8c1e0fdb44548d9ff0a88ce23 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sat, 4 Oct 2025 01:53:06 +0000
Subject: [PATCH 2/2] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 test-data/unit/check-expressions.test | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test-data/unit/check-expressions.test b/test-data/unit/check-expressions.test
index 7f3696e5eda0..650b8f5fb0de 100644
--- a/test-data/unit/check-expressions.test
+++ b/test-data/unit/check-expressions.test
@@ -2504,4 +2504,4 @@ class Color(Enum):
 def f() -> Color:
     return Color(Color.RED)
 
-[out]
\ No newline at end of file
+[out]