From 2c38013c7ff42756b787b1ecbb8f9fa7206a44a2 Mon Sep 17 00:00:00 2001
From: Saif Eddin Gmati <29315886+azjezz@users.noreply.github.com>
Date: Thu, 10 Nov 2022 19:48:59 +0100
Subject: [PATCH] fix: don't close argument type.

ref https://github.com/vimeo/psalm/pull/8691#discussion_r1019192376
---
 .../Type/Optional/FunctionReturnTypeProvider.php             | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/EventHandler/Type/Optional/FunctionReturnTypeProvider.php b/src/EventHandler/Type/Optional/FunctionReturnTypeProvider.php
index 2c0fbb3..896f434 100644
--- a/src/EventHandler/Type/Optional/FunctionReturnTypeProvider.php
+++ b/src/EventHandler/Type/Optional/FunctionReturnTypeProvider.php
@@ -28,9 +28,6 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
             return null;
         }
 
-        $clone = clone $argument_type;
-        $clone->possibly_undefined = true;
-
-        return $clone;
+        return $argument_type->setPossiblyUndefined(true);
     }
 }