From 38268f1c535bf5b9352e867cbe0387ca20f7b8b4 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Tue, 8 Dec 2020 18:12:39 +0100
Subject: [PATCH] LibJS: Create lexical scope for "catch" on the spot when
 throwing

---
 Libraries/LibJS/AST.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Libraries/LibJS/AST.cpp b/Libraries/LibJS/AST.cpp
index 565d8f347e..89aefe544f 100644
--- a/Libraries/LibJS/AST.cpp
+++ b/Libraries/LibJS/AST.cpp
@@ -1901,8 +1901,12 @@ Value TryStatement::execute(Interpreter& interpreter, GlobalObject& global_objec
     if (auto* exception = interpreter.exception()) {
         if (m_handler) {
             interpreter.vm().clear_exception();
-            ArgumentVector arguments { { m_handler->parameter(), exception->value() } };
-            interpreter.execute_statement(global_object, m_handler->body(), move(arguments));
+
+            HashMap<FlyString, Variable> parameters;
+            parameters.set(m_handler->parameter(), Variable { exception->value(), DeclarationKind::Var });
+            auto* catch_scope = interpreter.heap().allocate<LexicalEnvironment>(global_object, move(parameters), interpreter.vm().call_frame().scope);
+            TemporaryChange<ScopeObject*> scope_change(interpreter.vm().call_frame().scope, catch_scope);
+            interpreter.execute_statement(global_object, m_handler->body());
         }
     }