<!DOCTYPE HTML> <html> <!-- https://bugzilla.mozilla.org/show_bug.cgi?id=524175 --> <head> <title>Test for Bug 524175</title> <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script> <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/> <style> span::before ::before {} </style> </head> <body> <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=524175">Mozilla Bug 524175</a> <p id="display"></p> <div id="content" style="display: none"> </div> <pre id="test"> <script type="application/javascript"> /** Test for Bug 524175 **/ is(document.styleSheets[1].cssRules.length, 0, "Shouldn't have parsed that rule"); </script> </pre> </body> </html>