No longer OOM on invalid string length.

src/debug.cc

 // Copyright 2012 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 736 matching lines @@
   // Bail out if the index is invalid.
   if (index == -1) {
     return false;
   }
 
   // Find source and name for the requested script.
   Handle<String> source_code =
       isolate->bootstrapper()->NativesSourceLookup(index);
   Vector<const char> name = Natives::GetScriptName(index);
   Handle<String> script_name = factory->NewStringFromAscii(name);
+  ASSERT(!script_name.is_null());
   Handle<Context> context = isolate->native_context();
 
   // Compile the script.
   Handle<SharedFunctionInfo> function_info;
   function_info = Compiler::CompileScript(source_code,
                                           script_name, 0, 0,
                                           false,
                                           context,
                                           NULL, NULL, NO_CACHED_DATA,
                                           NATIVES_CODE);
@@ skipping 1825 matching lines @@
 
 Handle<Object> Debugger::MakeJSObject(Vector<const char> constructor_name,
                                       int argc,
                                       Handle<Object> argv[],
                                       bool* caught_exception) {
   ASSERT(isolate_->context() == *isolate_->debug()->debug_context());
 
   // Create the execution state object.
   Handle<String> constructor_str =
       isolate_->factory()->InternalizeUtf8String(constructor_name);
+  ASSERT(!constructor_str.is_null());
   Handle<Object> constructor(
       isolate_->global_object()->GetPropertyNoExceptionThrown(*constructor_str),
       isolate_);
   ASSERT(constructor->IsJSFunction());
   if (!constructor->IsJSFunction()) {
     *caught_exception = true;
     return isolate_->factory()->undefined_value();
   }
   Handle<Object> js_object = Execution::TryCall(
       Handle<JSFunction>::cast(constructor),
@@ skipping 1197 matching lines @@
     {
       Locker locker(reinterpret_cast<v8::Isolate*>(isolate_));
       isolate_->debugger()->CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal