Ignore pointer capture target while calculating click target

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

 // Copyright 2016 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 "core/input/MouseEventManager.h"
 
 #include "core/clipboard/DataObject.h"
 #include "core/clipboard/DataTransfer.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementTraversal.h"
@@ skipping 233 matching lines @@
   // FIXME: The Mac port achieves the same behavior by checking whether the
   // context menu is currently open in WebPage::mouseEvent(). Consider merging
   // the implementations.
   if (mouseEvent.button == WebPointerProperties::Button::Left &&
       mouseEvent.modifiers() & WebInputEvent::Modifiers::ControlKey)
     contextMenuEvent = true;
 #endif
 
   WebInputEventResult clickEventResult = WebInputEventResult::NotHandled;
   const bool shouldDispatchClickEvent = m_clickCount > 0 && !contextMenuEvent &&
-                                        target && m_clickNode &&
-                                        target->canParticipateInFlatTree() &&
+                                        m_clickNode &&
                                         m_clickNode->canParticipateInFlatTree();
   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.
-    if (m_clickNode == target) {
-      clickTargetNode = m_clickNode;
-      clickTargetNode->updateDistribution();
-    } else if (m_clickNode->document() == target->document()) {
-      m_clickNode->updateDistribution();
-      target->updateDistribution();
-      clickTargetNode = target->commonAncestor(
-          *m_clickNode, EventHandlingUtil::parentForClickEvent);
+    if (target && target->canParticipateInFlatTree()) {
+      if (m_clickNode == target) {
+        clickTargetNode = m_clickNode;
+        clickTargetNode->updateDistribution();
+      } else if (m_clickNode->document() == target->document()) {
+        m_clickNode->updateDistribution();
+        target->updateDistribution();
+        clickTargetNode = target->commonAncestor(
+            *m_clickNode, EventHandlingUtil::parentForClickEvent);
+      }
     }
 
     // This block is only for the purpose of gathering the metric and can be
     // removed as soon as we don't need the metric.
     if (targetWithoutCapture != target) {
       Node* alternativeClickTargetNode = nullptr;
-      if (m_clickNode == targetWithoutCapture) {
-        alternativeClickTargetNode = m_clickNode;
-      } else if (m_clickNode->document() == targetWithoutCapture->document()) {
-        alternativeClickTargetNode = targetWithoutCapture->commonAncestor(
-            *m_clickNode, EventHandlingUtil::parentForClickEvent);
+      if (targetWithoutCapture &&
+          targetWithoutCapture->canParticipateInFlatTree()) {
+        if (m_clickNode == targetWithoutCapture) {
+          alternativeClickTargetNode = m_clickNode;
+        } else if (m_clickNode->document() ==
+                   targetWithoutCapture->document()) {
+          alternativeClickTargetNode = targetWithoutCapture->commonAncestor(
+              *m_clickNode, EventHandlingUtil::parentForClickEvent);
+        }
       }
       if (alternativeClickTargetNode != clickTargetNode) {
         UseCounter::count(m_frame,
                           UseCounter::PointerEventClickRetargetCausedByCapture);
       }
+      // TODO(crbug.com/699933): The following line removes the effect of
+      // pointer capture.
+      clickTargetNode = alternativeClickTargetNode;
     }
 
     if (clickTargetNode) {
       clickEventResult = dispatchMouseEvent(
           clickTargetNode,
           !RuntimeEnabledFeatures::auxclickEnabled() ||
                   (mouseEvent.button == WebPointerProperties::Button::Left)
               ? EventTypeNames::click
               : EventTypeNames::auxclick,
           mouseEvent, canvasRegionId, nullptr);
@@ skipping 741 matching lines @@
 
 void MouseEventManager::setClickCount(int clickCount) {
   m_clickCount = clickCount;
 }
 
 bool MouseEventManager::mouseDownMayStartDrag() {
   return m_mouseDownMayStartDrag;
 }
 
 }  // namespace blink