LayoutTests/fast/css/attribute-selector-empty-value.html - WebKit - Git at Google

 <!DOCTYPE html><style type="text/css">div[foo~=""] { background-color: red; }</style>
 <div foo="">[~=] attribute selector looking for empty string in empty attribute (the text should not have red background)</div>
	<!DOCTYPE html><style type="text/css">div[foo~=""] { background-color: red; }</style>
	<div foo="">[~=] attribute selector looking for empty string in empty attribute (the text should not have red background)</div>