From 0cfe565d0afbcd31eadcc281b9017b5692911661 Mon Sep 17 00:00:00 2001
From: Brown <github@muglug.com>
Date: Mon, 9 Mar 2020 18:59:56 -0400
Subject: [PATCH] Fix #2952 - always be cloning

---
 .../Statements/ExpressionAnalyzer.php         |  2 +-
 tests/ClassStringTest.php                     | 33 +++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/ExpressionAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/ExpressionAnalyzer.php
index f40db7110a8..76683a342d3 100644
--- a/src/Psalm/Internal/Analyzer/Statements/ExpressionAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/ExpressionAnalyzer.php
@@ -1305,7 +1305,7 @@ private static function fleshOutAtomicType(
         if ($return_type instanceof Type\Atomic\TClassString
             && $return_type->as_type
         ) {
-            $new_as_type = $return_type->as_type;
+            $new_as_type = clone $return_type->as_type;
 
             self::fleshOutAtomicType(
                 $codebase,
diff --git a/tests/ClassStringTest.php b/tests/ClassStringTest.php
index 754079117ac..08c3e4378e3 100644
--- a/tests/ClassStringTest.php
+++ b/tests/ClassStringTest.php
@@ -695,6 +695,39 @@ public static function r() : string
                         }
                     }'
             ],
+            'traitClassStringClone' => [
+                '<?php
+                    trait Factory
+                    {
+                        /** @return class-string<static> */
+                        public static function getFactoryClass()
+                        {
+                            return static::class;
+                        }
+                    }
+
+                    class A
+                    {
+                        use Factory;
+
+                        public static function factory(): self
+                        {
+                            $class = static::getFactoryClass();
+                            return new $class;
+                        }
+                    }
+
+                    class B
+                    {
+                        use Factory;
+
+                        public static function factory(): self
+                        {
+                            $class = static::getFactoryClass();
+                            return new $class;
+                        }
+                    }'
+            ],
         ];
     }