DO NOT SUBMIT

Source/WebCore/dom/Range.cpp

Index: Source/WebCore/dom/Range.cpp
diff --git a/Source/WebCore/dom/Range.cpp b/Source/WebCore/dom/Range.cpp
index 423d43f26113c601e527b7521ecf2927fb6e095f..ee3272f7624f39392bb31e978434480cc20a6cf7 100644
--- a/Source/WebCore/dom/Range.cpp
+++ b/Source/WebCore/dom/Range.cpp
@@ -1534,6 +1534,36 @@ bool Range::containedByReadOnly() const
     return false;
 }
 
+bool Range::getLocationAndLength(unsigned& location, unsigned& length)
+{
+    location = notFound;
+    length = 0;
+
+    if (!startContainer())
+        return false;
+
+    Element* selectionRoot = ownerDocument()->frame()->selection()->rootEditableElement();
+    Element* scope = selectionRoot ? selectionRoot : ownerDocument()->documentElement();
+
+    // Mouse events may cause TSM to attempt to create an NSRange for a portion of the view
+    // that is not inside the current editable region.  These checks ensure we don't produce
+    // potentially invalid data when responding to such requests.
+    if (startContainer() != scope && !startContainer()->isDescendantOf(scope))
+        return false;
+    if (endContainer() != scope && !endContainer()->isDescendantOf(scope))
+        return false;
+
+    RefPtr<Range> testRange = Range::create(scope->document(), scope, 0, startContainer(), startOffset());
+    ASSERT(testRange->startContainer() == scope);
+    location = TextIterator::rangeLength(testRange.get());
+    
+    ExceptionCode ec;
+    testRange->setEnd(endContainer(), endOffset(), ec);
+    ASSERT(testRange->startContainer() == scope);
+    length = TextIterator::rangeLength(testRange.get()) - location;
+    return true;
+}
+
 Node* Range::firstNode() const
 {
     if (!m_start.container())