Range.compareBoundaryPoints should throw a NotSupportedError when how has not expected value

Source/core/dom/Range.cpp

Index: Source/core/dom/Range.cpp
diff --git a/Source/core/dom/Range.cpp b/Source/core/dom/Range.cpp
index 4bc3f5f8cbceff87ce8e2b33f29a03eea3d37a0a..6434ed8ecb4fafe77cb9454317bf3740ad270454 100644
--- a/Source/core/dom/Range.cpp
+++ b/Source/core/dom/Range.cpp
@@ -321,10 +321,10 @@ Range::CompareResults Range::compareNode(Node* refNode, ExceptionState& exceptio
     return NODE_INSIDE; // ends inside the range
 }
 
-short Range::compareBoundaryPoints(CompareHow how, const Range* sourceRange, ExceptionState& exceptionState) const
+short Range::compareBoundaryPoints(CompareHow how, const PassRefPtrWillBeRawPtr<Range> sourceRange, ExceptionState& exceptionState) const

[Yuta Kitamura, 2014/07/22 06:03:39]

nit: const seems unnecessary.

Just curious, TypeChecking=Interface requires PassRefPtr<> here?

The function does not save the Range object to anywhere, so
a pointer should be sufficient here.

[kangil_, 2014/07/22 08:41:49]

IMHO, const is generally good since it protects us from unexpected change. So,
if we don't have specific reason to touch sourceRange, then we can keep as it
is. :)
I think you are right. I habitually modified it. Do you want me to get it back
to a pointer as it was?

[Yuta Kitamura, 2014/07/22 09:22:43]

I'm not opposing to the use of const in general. I wanted to
point out the fact that |const RefPtr<T>| is not parallel to
|const T*| in terms of its meaning:

    const RefPtr<T>  <===>  T* const
    RefPtr<const T>  <===>  const T*
    (Read: [left hand side] is parallel to [right hand side])

|const RefPtr<T>| only prevents changing the pointer value.
The annotation is only meaningful within the function
implementation; from the caller's point of view, an argument
with type |const T| is exactly same as one declared as |T|.

If you are aware of these details and intentionally writing
this const, I'm fine with it. I just want to make sure you
understand the const usage well.
Yeah, please go ahead and write the change.

 {
-    if (!sourceRange) {
-        exceptionState.throwDOMException(NotFoundError, "The source range provided was null.");
+    if (!(how == START_TO_START || how == START_TO_END || how == END_TO_END || how == END_TO_START)) {
+        exceptionState.throwDOMException(NotSupportedError, "The comparison method provided must be one of 'START_TO_START', 'START_TO_END', 'END_TO_END', or 'END_TO_START'.");
         return 0;
     }
 
@@ -357,7 +357,7 @@ short Range::compareBoundaryPoints(CompareHow how, const Range* sourceRange, Exc
             return compareBoundaryPoints(m_start, sourceRange->m_end, exceptionState);
     }
 
-    exceptionState.throwDOMException(SyntaxError, "The comparison method provided must be one of 'START_TO_START', 'START_TO_END', 'END_TO_END', or 'END_TO_START'.");
+    ASSERT_NOT_REACHED();
     return 0;
 }