Update distribution on the nodes involved in click

third_party/WebKit/Source/core/input/EventHandler.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 1445 matching lines @@
         contextMenuEvent = true;
 #endif
 
     WebInputEventResult clickEventResult = WebInputEventResult::NotHandled;
     const bool shouldDispatchClickEvent = m_clickCount > 0
         && !contextMenuEvent
         && mev.innerNode() && m_clickNode
         && mev.innerNode()->canParticipateInFlatTree() && m_clickNode->canParticipateInFlatTree()
         && !(selectionController().hasExtendedSelection() && isLinkSelection(mev));
     if (shouldDispatchClickEvent) {
+        Node* clickTargetNode = nullptr;
         // Updates distribution because a 'mouseup' event listener can make the
         // tree dirty at dispatchMouseEvent() invocation above.
         // Unless distribution is updated, commonAncestor would hit ASSERT.
-        // Both m_clickNode and mev.innerNode() don't need to be updated
-        // because commonAncestor() will exit early if their documents are different.
-        m_clickNode->updateDistribution();
-        if (Node* clickTargetNode = mev.innerNode()->commonAncestor(
-            *m_clickNode, parentForClickEvent)) {
-
+        if (m_clickNode == mev.innerNode()) {
+            clickTargetNode = m_clickNode;
+            clickTargetNode->updateDistribution();
+        } else if (m_clickNode->document() == mev.innerNode()->document()) {
+            m_clickNode->updateDistribution();
+            mev.innerNode()->updateDistribution();
+            clickTargetNode = mev.innerNode()->commonAncestor(
+                *m_clickNode, parentForClickEvent);
+        }
+        if (clickTargetNode) {
             // Dispatch mouseup directly w/o calling updateMouseEventTargetNodeAndSendEvents
             // because the mouseup dispatch above has already updated it
             // correctly. Moreover, clickTargetNode is different from
             // mev.innerNode at drag-release.
             clickEventResult = toWebInputEventResult(clickTargetNode->dispatchMouseEvent(mev.event(),
                 EventTypeNames::click, m_clickCount));
         }
     }
 
     if (m_resizeScrollableArea) {
@@ skipping 2619 matching lines @@
 PlatformEvent::Modifiers EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return static_cast<PlatformEvent::Modifiers>(PlatformEvent::CtrlKey | PlatformEvent::AltKey);
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace blink