Certain attributes should be treated as case-insensitive when comparing them
Ported from jQuery bug http://bugs.jquery.com/ticket/12024
http://jsfiddle.net/timmywil/n8zDu/14/
The inputs in the example all have uppercase values for their attributes while the value in the selector is lowercase. When :not contains a complex selector, querySelectorAll fails and Sizzle handles the attribute comparisons but does not account for these attributes being case-insensitive. We can fix that, but it will probably require a list within Sizzle specifying which attributes are case-insensitive in both HTML and XML.
This is both low priority and valid. It all depends on how much size it takes to keep a table of all attributes affected (in both HTML and XML).
jQuery version of this issue: https://github.com/jquery/jquery/issues/5316