In the bottom of core.js, the following code segment is to determine which method reports the correct window size:

this[0] == window ?
      // Opera reports document.body.client[Width/Height] properly in both quirks and standards
      jQuery.browser.opera && document.body[ "client" + name ] ||
      // Safari reports inner[Width/Height] just fine (Mozilla and Opera include scroll bar widths)
      jQuery.browser.safari && window[ "inner" + name ] ||
      // Everyone else use document.documentElement or document.body depending on Quirks vs Standards mode
      document.compatMode == "CSS1Compat" && document.documentElement[ "client" + name ] || document.body[ "client" + name ] :

However, I think the code

jQuery.browser.opera && document.body[ "client" + name ] ||

is redundant because this discriminant has finally tries document.body['client'+name] yet.

How do you think?