Makes FunctionTemplate::HasInstance return true for a global proxy.

src/api.cc

 // Copyright 2012 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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 6368 matching lines @@
       isolate->OptionalRescheduleException(true);
     }
     return MaybeLocal<Object>();
   }
   return Utils::ToLocal(scope.CloseAndEscape(object));
 }
 
 bool FunctionTemplate::HasInstance(v8::Local<v8::Value> value) {
   auto self = Utils::OpenHandle(this);
   auto obj = Utils::OpenHandle(*value);
-  return obj->IsJSObject() && self->IsTemplateFor(i::JSObject::cast(*obj));
+  if (obj->IsJSObject() && self->IsTemplateFor(i::JSObject::cast(*obj))) {
+    return true;
+  }
+  if (obj->IsJSGlobalProxy()) {
+    // If it's a global proxy object, then test with the global object.
+    i::PrototypeIterator iter(i::JSObject::cast(*obj)->map());
+    if (iter.IsAtEnd()) return false;
+    return self->IsTemplateFor(iter.GetCurrent<i::JSGlobalObject>());
+  }
+  return false;
 }
 
 
 Local<External> v8::External::New(Isolate* isolate, void* value) {
   STATIC_ASSERT(sizeof(value) == sizeof(i::Address));
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   LOG_API(i_isolate, External, New);
   ENTER_V8(i_isolate);
   i::Handle<i::JSObject> external = i_isolate->factory()->NewExternal(value);
   return Utils::ExternalToLocal(external);
@@ skipping 3384 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8