Throw TypeError when reading global references through a JSProxy

src/objects.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 810 matching lines @@
     }                                                    \
   } while (false)
 
 
 // static
 MaybeHandle<Object> JSProxy::GetProperty(Isolate* isolate,
                                          Handle<JSProxy> proxy,
                                          Handle<Name> name,
                                          Handle<Object> receiver,
                                          LanguageMode language_mode) {
+  if (receiver->IsJSGlobalObject()) {
+    THROW_NEW_ERROR(
+        isolate,
+        NewTypeError(MessageTemplate::kReadGlobalReferenceThroughProxy, name),
+        Object);
+  }
+
   STACK_CHECK(MaybeHandle<Object>());
   Handle<Name> trap_name = isolate->factory()->get_string();
   // 1. Assert: IsPropertyKey(P) is true.
   // 2. Let handler be the value of the [[ProxyHandler]] internal slot of O.
   Handle<Object> handler(proxy->handler(), isolate);
   // 3. If handler is null, throw a TypeError exception.
   // 4. Assert: Type(handler) is Object.
   if (proxy->IsRevoked()) {
     THROW_NEW_ERROR(isolate,
                     NewTypeError(MessageTemplate::kProxyRevoked, trap_name),
@@ skipping 18524 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8