Attribute selectors of the form 'div[style]' and 'div[title]' do not work as I expect.

I expect 'div[style]' to match every <div> element that bears a style= attribute (regardless of whether that attribute's value is the empty string), and not to match any <div> elements that do not bear any style= attribute.

However, that selector matches every <div>, regardless of whether it has a style= attribute.

I have similar expectations for 'div[title]', except with the title= attribute rather than style=. That selector correctly excludes <div> elements with no title= attribute, but it incorrectly matches <div title=""> elements (with an empty string as the attribute value).

Reductions for both situations are attached. I expect each reduction to display three green-background boxes saying "OK"; a failure is indicated as a red-background box saying "FAIL".

I have tested this in Firefox 2, Firefox 3, Safari 3.0, and Opera 9.5; it behaves the same way in all of them.