Element.removeAttribute() with a non-existent attribute name

Neither the Level 2 DOM specification, nor the errata of that
specification seem to specify what should happen if you call
Element.removeAttribute() and pass the name of a non-existent attribute.
Since the spec does not say that an exception is thrown in this case,
I'd assume that the call is simply ignored.  On the other hand,
removeAttributeNode() throws an exception if the specified Attr node is
not found, and I wan't to be sure that removeAttribute() was not
intended to do the same thing.

Can anyone confirm that my assumption (i.e. ignore non-existent
attributes) is correct?

Finally, I'd be more comfortable with the spec. if this were formally
clarified for removeAttribute() and removeAttributeNS() in an erratum.

	  David Flanagan