From f61a9f2dc5c9dfbde87ef4920c7a8beb0be5c7ce Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 27 Jun 2021 00:37:07 +0200
Subject: [PATCH] LibJS: Don't extend `arguments` object to match the parameter
 count

The `arguments` object should only have the *arguments* as numeric
properties, not the *parameters*.

Given this function:

    function foo(a, b) {
        return arguments.length;
    }

Calling foo() with no arguments now correctly returns 0 instead of 2.
---
 Userland/Libraries/LibJS/Runtime/ScriptFunction.cpp | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/Userland/Libraries/LibJS/Runtime/ScriptFunction.cpp b/Userland/Libraries/LibJS/Runtime/ScriptFunction.cpp
index fd02d8a107..3d00c4bd4a 100644
--- a/Userland/Libraries/LibJS/Runtime/ScriptFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/ScriptFunction.cpp
@@ -170,9 +170,6 @@ Value ScriptFunction::execute_function_body()
                         argument_value = js_undefined();
                     }
 
-                    if (i >= execution_context_arguments.size())
-                        execution_context_arguments.resize(i + 1);
-                    execution_context_arguments[i] = argument_value;
                     vm.assign(param, argument_value, global_object(), true, vm.lexical_environment());
                 });