Prevent default actions for JS-generated mouse events other than click

Source/core/events/MouseEvent.cpp

 /*
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2005, 2006, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 90 matching lines @@
 
 MouseEvent::MouseEvent(const AtomicString& eventType, const MouseEventInit& initializer)
     : MouseRelatedEvent(eventType, initializer.bubbles(), initializer.cancelable(), initializer.view(), initializer.detail(), IntPoint(initializer.screenX(), initializer.screenY()),
         IntPoint(0 /* pageX */, 0 /* pageY */),
         IntPoint(initializer.movementX(), initializer.movementY()),
         initializer.ctrlKey(), initializer.altKey(), initializer.shiftKey(), initializer.metaKey(), false /* isSimulated */)
     , m_button(initializer.button())
     , m_buttons(initializer.buttons())
     , m_relatedTarget(initializer.relatedTarget())
     , m_dataTransfer(nullptr)
-    , m_syntheticEventType(PlatformMouseEvent::RealOrIndistinguishable)
+    , m_syntheticEventType(PlatformMouseEvent::FromScript)
 {
     initCoordinates(IntPoint(initializer.clientX(), initializer.clientY()));
 }
 
 MouseEvent::~MouseEvent()
 {
 }
 
 unsigned short MouseEvent::platformModifiersToButtons(unsigned modifiers)
 {
@@ skipping 23 matching lines @@
     initUIEvent(type, canBubble, cancelable, view, detail);
 
     m_screenLocation = IntPoint(screenX, screenY);
     m_ctrlKey = ctrlKey;
     m_altKey = altKey;
     m_shiftKey = shiftKey;
     m_metaKey = metaKey;
     m_button = button;
     m_buttons = buttons;
     m_relatedTarget = relatedTarget;
+    m_syntheticEventType = PlatformMouseEvent::FromScript;
 
     initCoordinates(IntPoint(clientX, clientY));
 
     // FIXME: m_isSimulated is not set to false here.
     // FIXME: m_dataTransfer is not set to nullptr here.
 }
 
 const AtomicString& MouseEvent::interfaceName() const
 {
     return EventNames::MouseEvent;
@@ skipping 70 matching lines @@
         m_screenLocation = mouseEvent->screenLocation();
         initCoordinates(mouseEvent->clientLocation());
     }
 }
 
 DEFINE_TRACE(SimulatedMouseEvent)
 {
     MouseEvent::trace(visitor);
 }
 
-PassRefPtrWillBeRawPtr<MouseEventDispatchMediator> MouseEventDispatchMediator::create(PassRefPtrWillBeRawPtr<MouseEvent> mouseEvent, MouseEventType mouseEventType)
+PassRefPtrWillBeRawPtr<MouseEventDispatchMediator> MouseEventDispatchMediator::create(PassRefPtrWillBeRawPtr<MouseEvent> mouseEvent)
 {
-    return adoptRefWillBeNoop(new MouseEventDispatchMediator(mouseEvent, mouseEventType));
+    return adoptRefWillBeNoop(new MouseEventDispatchMediator(mouseEvent));
 }
 
-MouseEventDispatchMediator::MouseEventDispatchMediator(PassRefPtrWillBeRawPtr<MouseEvent> mouseEvent, MouseEventType mouseEventType)
-    : EventDispatchMediator(mouseEvent), m_mouseEventType(mouseEventType)
+MouseEventDispatchMediator::MouseEventDispatchMediator(PassRefPtrWillBeRawPtr<MouseEvent> mouseEvent)
+    : EventDispatchMediator(mouseEvent)
 {
 }
 
 MouseEvent& MouseEventDispatchMediator::event() const
 {
     return toMouseEvent(EventDispatchMediator::event());
 }
 
 bool MouseEventDispatchMediator::dispatchEvent(EventDispatcher& dispatcher) const
 {
-    if (isSyntheticMouseEvent()) {
+    if (event().fromScript()) {
         event().eventPath().adjustForRelatedTarget(dispatcher.node(), event().relatedTarget());
         return dispatcher.dispatch();
     }
 
     if (isDisabledFormControl(&dispatcher.node()))
         return false;
 
     if (event().type().isEmpty())
         return true; // Shouldn't happen.
 
@@ skipping 18 matching lines @@
         event().button(), relatedTarget, event().buttons());
     if (event().defaultHandled())
         doubleClickEvent->setDefaultHandled();
     EventDispatcher::dispatchEvent(dispatcher.node(), MouseEventDispatchMediator::create(doubleClickEvent));
     if (doubleClickEvent->defaultHandled() || doubleClickEvent->defaultPrevented())
         return false;
     return !swallowEvent;
 }
 
 } // namespace blink