Wikimedia Bugzilla is closed!

I was trying to puzzle out table-sorting on Wikipedia using Firebug, and I noticed that ts_parseFloat() in wikibits.js assigns a value to num:

 num = parseFloat( s.replace(/[, ]/g, '').replace("\u2212", '-') );

Because there's no var or let, this adds num to the global scope -- before this line is reached, this.num is undefined, afterwards this.num has a value for all JavaScript.  A fix might be to use the existing local var newNum instead of num here.

I'm no JavaScript wizard, so I apologize if this is intentional.
There are several other variables that were probably intended to be local that get added to this. scope according to Firebug (this.i, etc.)