Accessible setSelection function should use VisiblePositions

third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp

 /*
 * Copyright (C) 2008 Apple 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:
 *
 * 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 1922 matching lines @@
         focusObject = focusObject->parentObject();
     }
 
     if (!anchorNode || !focusNode)
         return;
 
     LocalFrame* frame = getLayoutObject()->frame();
     if (!frame)
         return;
 
-    frame->selection().setSelection(VisibleSelection(
-        Position(anchorNode, selection.anchorOffset),
-        Position(focusNode, selection.focusOffset)));
+    // Set the selection based on visible positions, because the offsets in accessibility nodes
+    // are based on visible indexes, which often skips redundant whitespace, for example.
+    VisiblePosition anchorVisiblePosition = anchorNode->isTextNode()
+        ? blink::visiblePositionForIndex(selection.anchorOffset, anchorNode->parentNode())
+        : createVisiblePosition(Position(anchorNode, selection.anchorOffset));
+    VisiblePosition focusVisiblePosition = focusNode->isTextNode()
+        ? blink::visiblePositionForIndex(selection.focusOffset, focusNode->parentNode())
+        : createVisiblePosition(Position(focusNode, selection.focusOffset));
+    frame->selection().setSelection(VisibleSelection(anchorVisiblePosition, focusVisiblePosition));
 }
 
 bool AXLayoutObject::isValidSelectionBound(const AXObject* boundObject) const
 {
     return getLayoutObject() && boundObject && !boundObject->isDetached()
         && boundObject->isAXLayoutObject() && boundObject->getLayoutObject()
         && boundObject->getLayoutObject()->frame() == getLayoutObject()->frame()
         && &boundObject->axObjectCache() == &axObjectCache();
 }
 
@@ skipping 515 matching lines @@
         if (label && label->layoutObject()) {
             LayoutRect labelRect = axObjectCache().getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink