From 05f2d01cb68a3cfa64a20738309e5493ab631aba Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Wed, 14 Oct 2020 21:35:46 -0400
Subject: [PATCH] Fix #4326 - Prevent later remapping of properties

---
 .../Fetch/InstancePropertyFetchAnalyzer.php   |  4 +-
 tests/Template/ClassTemplateTest.php          | 47 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/InstancePropertyFetchAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/InstancePropertyFetchAnalyzer.php
index 49e058c66..583ddf31b 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/InstancePropertyFetchAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/InstancePropertyFetchAnalyzer.php
@@ -1004,9 +1004,7 @@ class InstancePropertyFetchAnalyzer
                         $class_storage,
                         $declaring_class_storage
                     );
-                }
-
-                if ($lhs_type_part instanceof TGenericObject) {
+                } elseif ($lhs_type_part instanceof TGenericObject) {
                     $class_property_type = self::localizePropertyType(
                         $codebase,
                         $class_property_type,
diff --git a/tests/Template/ClassTemplateTest.php b/tests/Template/ClassTemplateTest.php
index 20746c342..f788a6200 100644
--- a/tests/Template/ClassTemplateTest.php
+++ b/tests/Template/ClassTemplateTest.php
@@ -3005,7 +3005,7 @@ class ClassTemplateTest extends TestCase
                         }
                     }'
             ],
-            'flippedParamsInside' => [
+            'flippedParamsMethodInside' => [
                 '<?php
                     /**
                      * @template A
@@ -3026,7 +3026,7 @@ class ClassTemplateTest extends TestCase
                         }
                     }'
             ],
-            'flippedParamsOutside' => [
+            'flippedParamsMethodOutside' => [
                 '<?php
                     /**
                      * @template B
@@ -3048,6 +3048,49 @@ class ClassTemplateTest extends TestCase
                         public abstract function getTraversable() : Traversable;
                     }'
             ],
+            'flippedParamsPropertyInside' => [
+                '<?php
+                    /**
+                     * @template A
+                     * @template B
+                     */
+                    abstract class Foo
+                    {
+                        /** @var Traversable<A, B> */
+                        public $traversable;
+
+                        /**
+                         * @param Foo<B, A> $flipped
+                         * @return Traversable<B, A>
+                         */
+                        public function getFlippedTraversable(Foo $flipped): Traversable
+                        {
+                            return $flipped->traversable;
+                        }
+                    }'
+            ],
+            'flippedParamsPropertyOutside' => [
+                '<?php
+                    /**
+                     * @template B
+                     * @template A
+                     * @param Foo<B, A> $flipped
+                     * @return Traversable<B, A>
+                     */
+                    function getFlippedTraversable(Foo $flipped): Traversable {
+                        return $flipped->traversable;
+                    }
+
+                    /**
+                     * @template A
+                     * @template B
+                     */
+                    abstract class Foo
+                    {
+                        /** @var Traversable<A, B> */
+                        public $traversable;
+                    }'
+            ],
         ];
     }