Fix access on matched T[K]

src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php

@@ -488,8 +488,6 @@ class ArrayFetchAnalyzer
                                             if ($offset_as instanceof Type\Atomic\TTemplateKeyOf
                                                 && $offset_as->param_name === $original_type->param_name
                                                 && $offset_as->defining_class === $original_type->defining_class
-                                                && $offset_atomic_type->defining_class
-                                                    === $original_type->defining_class
                                             ) {
                                                 $type->type_params[1] = new Type\Union([
                                                     new Type\Atomic\TTemplateIndexedAccess(

src/Psalm/Type/Atomic.php

@@ -189,6 +189,7 @@ abstract class Atomic
 
         if (isset($template_type_map[$value])) {
             $first_class = array_keys($template_type_map[$value])[0];
+
             return new TTemplateParam(
                 $value,
                 $template_type_map[$value][$first_class][0],

tests/Template/TemplateTest.php

@@ -2373,7 +2373,7 @@ class TemplateTest extends TestCase
                     '$c' => 'int',
                 ]
             ],
-            'keyOfClassTemplate' => [
+            'keyOfClassTemplateAcceptingIndexedAccess' => [
                 '<?php
                     /**
                      * @template TData as array
@@ -2391,13 +2391,6 @@ class TemplateTest extends TestCase
                             $this->data = $data;
                         }
 
-                        /**
-                         * @param key-of<TData> $property
-                         */
-                        public function __get(string $property) {
-                            return $this->data[$property] ?? null;
-                        }
-
                         /**
                          * @template K as key-of<TData>
                          *
@@ -2409,6 +2402,36 @@ class TemplateTest extends TestCase
                         }
                     }'
             ],
+            'keyOfClassTemplateReturningIndexedAccess' => [
+                '<?php
+                    /**
+                     * @template TData as array
+                     */
+                    abstract class DataBag {
+                        /**
+                         * @var TData
+                         */
+                        protected $data;
+
+                        /**
+                         * @param TData $data
+                         */
+                        public function __construct(array $data) {
+                            $this->data = $data;
+                        }
+
+                        /**
+                         * @template K as key-of<TData>
+                         *
+                         * @param K $property
+                         *
+                         * @return TData[K]
+                         */
+                        public function __get(string $property) {
+                            return $this->data[$property];
+                        }
+                    }'
+            ],
             'unionTOrClassStringTPassedClassString' => [
                 '<?php
                     /**