Version 3.5.5.

src/apinatives.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 31 matching lines @@
 
 
 function Instantiate(data, name) {
   if (!%IsTemplate(data)) return data;
   var tag = %GetTemplateField(data, kApiTagOffset);
   switch (tag) {
     case kFunctionTag:
       return InstantiateFunction(data, name);
     case kNewObjectTag:
       var Constructor = %GetTemplateField(data, kApiConstructorOffset);
-      var result = Constructor ? new (Instantiate(Constructor))() : {};
+      // Note: Do not directly use a function template as a condition, our
+      // internal ToBoolean doesn't handle that!
+      var result = typeof Constructor === 'undefined' ?
+          {} : new (Instantiate(Constructor))();
       ConfigureTemplateInstance(result, data);
       result = %ToFastProperties(result);
       return result;
     default:
       throw 'Unknown API tag <' + tag + '>';
   }
 }
 
 
 function InstantiateFunction(data, name) {
   // We need a reference to kApiFunctionCache in the stack frame
   // if we need to bail out from a stack overflow.
   var cache = kApiFunctionCache;
   var serialNumber = %GetTemplateField(data, kApiSerialNumberOffset);
   var isFunctionCached =
    (serialNumber in cache) && (cache[serialNumber] != kUninitialized);
   if (!isFunctionCached) {
     try {
       cache[serialNumber] = null;
       var fun = %CreateApiFunction(data);
       if (name) %FunctionSetName(fun, name);
       cache[serialNumber] = fun;
       var prototype = %GetTemplateField(data, kApiPrototypeTemplateOffset);
       var flags = %GetTemplateField(data, kApiFlagOffset);
-      fun.prototype = prototype ? Instantiate(prototype) : {};
+      // Note: Do not directly use an object template as a condition, our
+      // internal ToBoolean doesn't handle that!
+      fun.prototype = typeof prototype === 'undefined' ?
+          {} : Instantiate(prototype);
       if (flags & (1 << kReadOnlyPrototypeBit)) {
         %FunctionSetReadOnlyPrototype(fun);
       }
       %SetProperty(fun.prototype, "constructor", fun, DONT_ENUM);
       var parent = %GetTemplateField(data, kApiParentTemplateOffset);
-      if (parent) {
+      // Note: Do not directly use a function template as a condition, our
+      // internal ToBoolean doesn't handle that!
+      if (!(typeof parent === 'undefined')) {
         var parent_fun = Instantiate(parent);
         fun.prototype.__proto__ = parent_fun.prototype;
       }
       ConfigureTemplateInstance(fun, data);
     } catch (e) {
       cache[serialNumber] = kUninitialized;
       throw e;
     }
   }
   return cache[serialNumber];
@@ skipping 11 matching lines @@
         var prop_data = properties[i + 2];
         var attributes = properties[i + 3];
         var value = Instantiate(prop_data, name);
         %SetProperty(obj, name, value, attributes);
       }
     } finally {
       if (requires_access_checks) %EnableAccessChecks(obj);
     }
   }
 }