From 019d49816879fc814097914d3e3ce7c7e1b081ed Mon Sep 17 00:00:00 2001
From: Leo Balter <leonardo.balter@gmail.com>
Date: Thu, 30 Jul 2020 12:55:35 -0700
Subject: [PATCH] Normative: Verify if Binding is preserved for obj's
 SetMutableBinding (#2094)

Verify binding existence in the object's SetMutableBinding on Strict Mode.

Closes #2093
Ref #467
Ref https://github.com/tc39/test262/issues/427
---
 spec.html | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/spec.html b/spec.html
index 9e99d7cc8c..7dd4868c0d 100644
--- a/spec.html
+++ b/spec.html
@@ -6626,6 +6626,8 @@ <h1>SetMutableBinding ( _N_, _V_, _S_ )</h1>
           <emu-alg>
             1. Let _envRec_ be the object Environment Record for which the method was invoked.
             1. Let _bindings_ be the binding object for _envRec_.
+            1. Let _stillExists_ be ? HasProperty(_bindings_, _N_).
+            1. If _stillExists_ is *false* and _S_ is *true*, throw a *ReferenceError* exception.
             1. Return ? Set(_bindings_, _N_, _V_, _S_).
           </emu-alg>
         </emu-clause>