kriskowal/es5-shim — comment on commit 6f7878ed30d5c1f06c5978a06f71cf461404c0e7
File:  line 0
By michaelficarra:

@rosenfeld: [es5 section 9.4 step 2](http://es5.github.com/#x9.4) says that `ToInteger` produces `+0` on `NaN` values. I'd say this is as much a fix as any I've ever seen.