Webkit browser update slowed down massively using a.hide(); b.filter(':visible')

[gavin@…]

See ​http://phrogz.net/tmp/webkit-jquery-browser-update-slowdown.html and follow the instructions there.

In summary, there are two jQuery objects with distinct sets of elements, 'classes' (100 <p> elements) and 'methods' (1500 <p> elements). If I write the code:

    classes.filter(':visible');
    methods.hide();

then everything is fine. However, if I change the order of those two statements, the web browser takes 40-500x longer to update the page after the JS is complete.

This bug reproduces on Chrome and Safari, but not Firefox. As such, I've also filed this as a Webkit bug: ​https://bugs.webkit.org/show_bug.cgi?id=69464

​https://bugs.webkit.org/show_bug.cgi?id=69464

[dmethvin]

I profiled it as well and the bottleneck doesn't appear to be inside a jQuery method. That points to an issue with Webkit, but of course this is a relatively pathological case given the number of elements being processed. If you find something we can change to fix the problem please let us know.