Codier/angular.js — comment on commit dad93f3cbf5fa8e1db43f7ff3d44793bc7f9ba17
File: src/Angular.js line 644
By esprehn:

That won't work because isNaN coerces the types. isNaN("foo") is true. Just check that (o1 != o1 && o2 != o2) which can only be true if both are NaN.

(Sorry my earlier one had t1 != t1 which is the type not the value.)