From 8c236f411a20ad96bbaf650095fe30fa1cec7bda Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Tue, 12 May 2020 15:07:10 -0400
Subject: [PATCH] Fix #3353 - allow extending nested when nested as type is
 mixed

---
 src/Psalm/Internal/Analyzer/ClassAnalyzer.php |  6 +++++-
 tests/Template/ClassTemplateExtendsTest.php   | 13 +++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/ClassAnalyzer.php b/src/Psalm/Internal/Analyzer/ClassAnalyzer.php
index 6f69394ea..d15d42a07 100644
--- a/src/Psalm/Internal/Analyzer/ClassAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/ClassAnalyzer.php
@@ -2038,7 +2038,7 @@ class ClassAnalyzer extends ClassLikeAnalyzer
                                 if (IssueBuffer::accepts(
                                     new InvalidTemplateParam(
                                         'Extended template param ' . $template_name
-                                            . ' expects type ' . $template_type[0]->getId()
+                                            . ' expects type ' . $template_type_copy->getId()
                                             . ', type ' . $extended_type->getId() . ' given',
                                         $code_location
                                     ),
@@ -2051,6 +2051,10 @@ class ClassAnalyzer extends ClassLikeAnalyzer
                                     $declaring_class => [$extended_type]
                                 ];
                             }
+                        } else {
+                            $previous_extended[$template_name] = [
+                                $declaring_class => [$extended_type]
+                            ];
                         }
                     }
                 }
diff --git a/tests/Template/ClassTemplateExtendsTest.php b/tests/Template/ClassTemplateExtendsTest.php
index d70d2624c..4a50f3a9b 100644
--- a/tests/Template/ClassTemplateExtendsTest.php
+++ b/tests/Template/ClassTemplateExtendsTest.php
@@ -4079,6 +4079,19 @@ class ClassTemplateExtendsTest extends TestCase
                         }
                     }'
             ],
+            'extendIteratorIterator' => [
+                '<?php
+                    /**
+                     * @template-covariant TKey
+                     * @template-covariant TValue
+                     *
+                     * @template-extends IteratorIterator<TKey, TValue, Traversable<TKey, TValue>>
+                     */
+                    abstract class MyFilterIterator extends IteratorIterator {
+                         /** @return bool */
+                         public abstract function accept () {}
+                    }'
+            ],
         ];
     }