On line 1353, there is the test:

var chars = jQuery.browser.safari && parseInt(jQuery.browser.version) < 417

The bug you're working around was fixed in WebKit build 417.5. See:

http://trac.webkit.org/projects/webkit/browser/tags/JavaScriptCore-418/JavaScriptCore/ChangeLog

So I think the line 1353 test needs to be something like:

jQuery.browser.safari && jQuery.browser.version < 417.5

but I don't know exactly how the version comparison works (int, float, etc.).

Yes, I was forced to test my website on a WebKit build 417.2, and the jQuery code bombed. I don't have that build myself, it's on my client's machine, so I can't make a test case or anything like that. For our site, I changed the line to read parseInt(jQuery.browser.version) < 418 which made our client happy, but I guess that's not technically correct either.