:hover style not applied on hover if its display property is different from original style's

Source/core/page/DragController.cpp

 /*
  * Copyright (C) 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Google Inc.
  *
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 794 matching lines @@
         if (!dragImage) {
             FontRenderingMode renderingMode = src->settings() ? src->settings()->fontRenderingMode() : NormalRenderingMode;
             float deviceScaleFactor = src->page() ? src->page()->deviceScaleFactor() : 1;
             dragImage = createDragImageForLink(linkURL, hitTestResult.textContent(), renderingMode, deviceScaleFactor);
             IntSize size = dragImageSize(dragImage);
             m_dragOffset = IntPoint(-size.width() / 2, -LinkDragBorderInset);
             dragLoc = IntPoint(mouseDraggedPoint.x() + m_dragOffset.x(), mouseDraggedPoint.y() + m_dragOffset.y());
         }
         doSystemDrag(dragImage, dragLoc, mouseDraggedPoint, clipboard, src, true);
     } else if (state.m_dragType == DragSourceActionDHTML) {
-        ASSERT(m_dragSourceAction & DragSourceActionDHTML);
-        doSystemDrag(dragImage, dragLoc, dragOrigin, clipboard, src, false);
+        if (dragImage) {
+            ASSERT(m_dragSourceAction & DragSourceActionDHTML);
+            doSystemDrag(dragImage, dragLoc, dragOrigin, clipboard, src, false);
+        } else {
+            startedDrag = false;
+        }
     } else {
         // draggableNode() determined an image or link node was draggable, but it turns out the
         // image or link had no URL, so there is nothing to drag.
         startedDrag = false;
     }
 
     if (dragImage)
         deleteDragImage(dragImage);
     return startedDrag;
 }
@@ skipping 95 matching lines @@
 #endif
     return maxDragImageSize;
 }
 
 void DragController::cleanupAfterSystemDrag()
 {
 }
 
 } // namespace WebCore