From cb3a7931c4469f9ce4ddad47d8b1582dad7bcd98 Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Tue, 13 Oct 2020 08:32:26 -0400
Subject: [PATCH] Fix #4315 - prevent crash when setting unknown property in
 finally

---
 .../Internal/Analyzer/Statements/Block/TryAnalyzer.php     | 2 +-
 tests/TryCatchTest.php                                     | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Block/TryAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Block/TryAnalyzer.php
index 8f66d4fb5c1..1dad25426d9 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Block/TryAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Block/TryAnalyzer.php
@@ -537,7 +537,7 @@ function ($fq_catch_class) use ($codebase): Type\Atomic {
                             $finally_context->vars_in_scope[$var_id],
                             $codebase
                         );
-                    } else {
+                    } elseif (isset($finally_context->vars_in_scope[$var_id])) {
                         $context->vars_in_scope[$var_id] = clone $finally_context->vars_in_scope[$var_id];
                     }
                 }
diff --git a/tests/TryCatchTest.php b/tests/TryCatchTest.php
index 79cc072617a..eee38f7dd08 100644
--- a/tests/TryCatchTest.php
+++ b/tests/TryCatchTest.php
@@ -365,6 +365,13 @@ class_alias(
                         }
                     }'
             ],
+            'suppressUndefinedVarInFinally' => [
+                '<?php
+                    try {} finally {
+                        /** @psalm-suppress UndefinedGlobalVariable, MixedPropertyAssignment */
+                        $event->end = null;
+                    }',
+            ],
         ];
     }