bindings: Use Maybe version of Call()

Source/bindings/core/v8/V8ErrorHandler.cpp

 /*
  * Copyright (C) 2010 Google Inc. 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
@@ skipping 39 matching lines @@
 v8::Local<v8::Value> V8ErrorHandler::callListenerFunction(ScriptState* scriptState, v8::Local<v8::Value> jsEvent, Event* event)
 {
     if (!event->hasInterface(EventNames::ErrorEvent))
         return V8EventListener::callListenerFunction(scriptState, jsEvent, event);
 
     ErrorEvent* errorEvent = static_cast<ErrorEvent*>(event);
     if (errorEvent->world() && errorEvent->world() != &world())
         return v8::Null(isolate());
 
     v8::Local<v8::Object> listener = getListenerObject(scriptState->executionContext());
     v8::Local<v8::Value> returnValue;

[Yuki, 2015/04/17 09:59:23]

Move this line just before you really need returnValue variable.

[bashi, 2015/04/21 00:15:40]

Done.

-    if (!listener.IsEmpty() && listener->IsFunction()) {
-        v8::Local<v8::Function> callFunction = v8::Local<v8::Function>::Cast(listener);
-        v8::Local<v8::Object> thisValue = scriptState->context()->Global();
+    if (listener.IsEmpty() || !listener->IsFunction())
+        return v8::Null(isolate());
 
-        v8::Local<v8::Object> eventObject;
-        if (!jsEvent->ToObject(scriptState->context()).ToLocal(&eventObject))
-            return v8::Null(isolate());
-        v8::Local<v8::Value> error = V8HiddenValue::getHiddenValue(isolate(), eventObject, V8HiddenValue::error(isolate()));
-        if (error.IsEmpty())
-            error = v8::Null(isolate());
+    v8::Local<v8::Function> callFunction = v8::Local<v8::Function>::Cast(listener);
+    v8::Local<v8::Object> thisValue = scriptState->context()->Global();
 
-        v8::Local<v8::Value> parameters[5] = { v8String(isolate(), errorEvent->message()), v8String(isolate(), errorEvent->filename()), v8::Integer::New(isolate(), errorEvent->lineno()), v8::Integer::New(isolate(), errorEvent->colno()), error };
-        v8::TryCatch tryCatch;
-        tryCatch.SetVerbose(true);
-        if (scriptState->executionContext()->isWorkerGlobalScope())
-            returnValue = V8ScriptRunner::callFunction(callFunction, scriptState->executionContext(), thisValue, WTF_ARRAY_LENGTH(parameters), parameters, isolate());
-        else
-            returnValue = ScriptController::callFunction(scriptState->executionContext(), callFunction, thisValue, WTF_ARRAY_LENGTH(parameters), parameters, isolate());
-    }
+    v8::Local<v8::Object> eventObject;
+    if (!jsEvent->ToObject(scriptState->context()).ToLocal(&eventObject))
+        return v8::Null(isolate());
+    v8::Local<v8::Value> error = V8HiddenValue::getHiddenValue(isolate(), eventObject, V8HiddenValue::error(isolate()));
+    if (error.IsEmpty())
+        error = v8::Null(isolate());
+
+    v8::Local<v8::Value> parameters[5] = { v8String(isolate(), errorEvent->message()), v8String(isolate(), errorEvent->filename()), v8::Integer::New(isolate(), errorEvent->lineno()), v8::Integer::New(isolate(), errorEvent->colno()), error };
+    v8::TryCatch tryCatch;
+    tryCatch.SetVerbose(true);
+    v8::MaybeLocal<v8::Value> result;
+    if (scriptState->executionContext()->isWorkerGlobalScope())

[haraken, 2015/04/18 23:10:47]

Nit: I'd add { } since the clause is long.

[bashi, 2015/04/21 00:15:40]

Done.

+        result = V8ScriptRunner::callFunction(callFunction, scriptState->executionContext(), thisValue, WTF_ARRAY_LENGTH(parameters), parameters, isolate());
+    else
+        result = ScriptController::callFunction(scriptState->executionContext(), callFunction, thisValue, WTF_ARRAY_LENGTH(parameters), parameters, isolate());
+    if (!result.ToLocal(&returnValue))
+        return v8::Null(isolate());
+
     return returnValue;
 }
 
 // static
 void V8ErrorHandler::storeExceptionOnErrorEventWrapper(v8::Isolate* isolate, ErrorEvent* event, v8::Local<v8::Value> data, v8::Local<v8::Object> creationContext)
 {
     v8::Local<v8::Value> wrappedEvent = toV8(event, creationContext, isolate);
     if (!wrappedEvent.IsEmpty()) {
         ASSERT(wrappedEvent->IsObject());
         V8HiddenValue::setHiddenValue(isolate, v8::Local<v8::Object>::Cast(wrappedEvent), V8HiddenValue::error(isolate), data);
     }
 }
 
 bool V8ErrorHandler::shouldPreventDefault(v8::Local<v8::Value> returnValue)
 {
     return returnValue->IsBoolean() && returnValue.As<v8::Boolean>()->Value();
 }
 
 } // namespace blink