*v8::String::Utf8Value can return NULL.

chrome/renderer/module_system.cc

 // Copyright (c) 2012 The Chromium 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 "chrome/renderer/module_system.h"
 
 #include "base/bind.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebScopedMicrotaskSuppression.h"
 
 namespace {
@@ skipping 60 matching lines @@
   if (!message->GetScriptResourceName().IsEmpty()) {
     resource_name =
         *v8::String::Utf8Value(message->GetScriptResourceName()->ToString());
   }
 
   std::string error_message = "<no error message>";
   if (!message->Get().IsEmpty())
     error_message = *v8::String::Utf8Value(message->Get());
 
   std::string stack_trace = "<stack trace unavailable>";
-  if (!try_catch.StackTrace().IsEmpty())
-    stack_trace = *v8::String::Utf8Value(try_catch.StackTrace());
+  if (!try_catch.StackTrace().IsEmpty()) {
+    v8::String::Utf8Value stack_value(try_catch.StackTrace());

[eaugusti, 2012/08/27 22:39:55]

I think this should be v8::Handle<v8::String::Utf8Value>, and a HandleScope
should be declared.

+    if (*stack_value)
+      stack_trace.assign(*stack_value, stack_value.length());
+    else
+      stack_trace = "<could not convert stack trace to string>";
+  }
 
   LOG(ERROR) << "[" << resource_name << "(" << message->GetLineNumber() << ")] "
              << error_message
              << "{" << stack_trace << "}";
 }
 
 void ModuleSystem::Require(const std::string& module_name) {
   v8::HandleScope handle_scope;
   RequireForJsInner(v8::String::New(module_name.c_str()));
 }
@@ skipping 158 matching lines @@
   v8::Handle<v8::String> left =
       v8::String::New("(function(require, requireNative, exports) {");
   v8::Handle<v8::String> right = v8::String::New("\n})");
   return handle_scope.Close(
       v8::String::Concat(left, v8::String::Concat(source, right)));
 }
 
 v8::Handle<v8::Value> ModuleSystem::ThrowException(const std::string& message) {
   return v8::ThrowException(v8::String::New(message.c_str()));
 }