bindings: Use Maybe version of v8::String::NewFromUtf8()

Source/bindings/core/v8/V8Binding.h

 /*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * Copyright (C) 2012 Ericsson AB. 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.
@@ skipping 329 matching lines @@
 // Return a V8 external string that shares the underlying buffer with the given
 // WebCore string. The reference counting mechanism is used to keep the
 // underlying buffer alive while the string is still live in the V8 engine.
 inline v8::Handle<v8::String> v8String(v8::Isolate* isolate, const String& string)
 {
     if (string.isNull())
         return v8::String::Empty(isolate);
     return V8PerIsolateData::from(isolate)->stringCache()->v8ExternalString(string.impl(), isolate);
 }
 
-inline v8::Handle<v8::String> v8AtomicString(v8::Isolate* isolate, const char* str)
+inline v8::Handle<v8::String> v8AtomicString(v8::Isolate* isolate, const char* str, int length = -1)
 {
     ASSERT(isolate);
-    return v8::String::NewFromUtf8(isolate, str, v8::String::kInternalizedString, strlen(str));
-}
-
-inline v8::Handle<v8::String> v8AtomicString(v8::Isolate* isolate, const char* str, size_t length)
-{
-    ASSERT(isolate);
-    return v8::String::NewFromUtf8(isolate, str, v8::String::kInternalizedString, length);
+    v8::Local<v8::String> value;
+    if (LIKELY(v8::String::NewFromUtf8(isolate, str, v8::NewStringType::kInternalized, length).ToLocal(&value)))
+        return value;
+    return v8::String::Empty(isolate);

[pfeldman, 2015/03/25 05:43:37]

At this point we know that there is a bug in the code. The problem has already
occurred, we know that the subsequent execution is going to be erroneous. For
example string created from the embedder notification did not make its way into
v8. Since we don't face any security risks such as UAF, we should definitely
crash the renderer on the call site and report it. It is our only option to fix
this bug, what you are doing is masking it.

[bashi, 2015/03/25 05:50:09]

OK, How about having RELEASE_ASSERT() here then?

[yurys, 2015/03/25 07:07:22]

Having RELEASE_ASSERT_NOT_REACHED() here would be great. You just need to make
sure that there is no code that checks for empty handle returned from
v8AtomicString and recovers from the problem. Adding RELEASE_ASSERT here would
regress such code.

 }
 
 inline v8::Handle<v8::Value> v8Undefined()
 {
     return v8::Handle<v8::Value>();
 }
 
 // Conversion flags, used in toIntXX/toUIntXX.
 enum IntegerConversionConfiguration {
     NormalConversion,
@@ skipping 597 matching lines @@
 PassRefPtr<TraceEvent::ConvertableToTraceFormat> devToolsTraceEventData(v8::Isolate*, ExecutionContext*, v8::Handle<v8::Function>);
 
 // Callback functions used by generated code.
 CORE_EXPORT void v8ConstructorAttributeGetter(v8::Local<v8::Name> propertyName, const v8::PropertyCallbackInfo<v8::Value>&);
 
 typedef void (*InstallTemplateFunction)(v8::Local<v8::FunctionTemplate>, v8::Isolate*);
 
 } // namespace blink
 
 #endif // V8Binding_h