Resolve references to "this" the same way as normal variables

src/runtime/runtime-scopes.cc

 // Copyright 2014 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/v8.h"
 
 #include "src/accessors.h"
 #include "src/arguments.h"
 #include "src/frames-inl.h"
 #include "src/runtime/runtime-utils.h"
@@ skipping 231 matching lines @@
   if (attributes != ABSENT && holder->IsJSGlobalObject()) {
     return DeclareGlobals(isolate, Handle<JSGlobalObject>::cast(holder), name,
                           value, attr, is_var, is_const, is_function);
   }
   if (context_arg->has_extension() &&
       context_arg->extension()->IsJSGlobalObject()) {
     Handle<JSGlobalObject> global(
         JSGlobalObject::cast(context_arg->extension()), isolate);
     return DeclareGlobals(isolate, global, name, value, attr, is_var, is_const,
                           is_function);
+  } else if (context->IsScriptContext()) {
+    DCHECK(context->global_object()->IsJSGlobalObject());
+    Handle<JSGlobalObject> global(
+        JSGlobalObject::cast(context->global_object()), isolate);
+    return DeclareGlobals(isolate, global, name, value, attr, is_var, is_const,
+                          is_function);
   }
 
   if (attributes != ABSENT) {
     // The name was declared before; check for conflicting re-declarations.
     if (is_const || (attributes & READ_ONLY) != 0) {
       return ThrowRedeclarationError(isolate, name);
     }
 
     // Skip var re-declarations.
     if (is_var) return isolate->heap()->undefined_value();
@@ skipping 55 matching lines @@
   PropertyAttributes attr =
       static_cast<PropertyAttributes>(DONT_DELETE | READ_ONLY);
 
   // Strict mode handling not needed (legacy const is disallowed in strict
   // mode).
 
   // The declared const was configurable, and may have been deleted in the
   // meanwhile. If so, re-introduce the variable in the context extension.
   if (attributes == ABSENT) {
     Handle<Context> declaration_context(context_arg->declaration_context());
-    DCHECK(declaration_context->has_extension());
-    holder = handle(declaration_context->extension(), isolate);
+    if (declaration_context->IsScriptContext()) {
+      holder = handle(declaration_context->global_object(), isolate);
+    } else {
+      DCHECK(declaration_context->has_extension());
+      holder = handle(declaration_context->extension(), isolate);
+    }
     CHECK(holder->IsJSObject());
   } else {
     // For JSContextExtensionObjects, the initializer can be run multiple times
     // if in a for loop: for (var i = 0; i < 2; i++) { const x = i; }. Only the
     // first assignment should go through. For JSGlobalObjects, additionally any
     // code can run in between that modifies the declared property.
     DCHECK(holder->IsJSGlobalObject() || holder->IsJSContextExtensionObject());
 
     LookupIterator it(holder, name, LookupIterator::HIDDEN_SKIP_INTERCEPTOR);
     Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
@@ skipping 780 matching lines @@
   return Smi::FromInt(frame->GetArgumentsLength());
 }
 
 
 RUNTIME_FUNCTION(Runtime_Arguments) {
   SealHandleScope shs(isolate);
   return __RT_impl_Runtime_GetArgumentsProperty(args, isolate);
 }
 }
 }  // namespace v8::internal