documentcloud/underscore — Issue #403: _.map() doesn't set correct length in fallback.
Author: jdalton
Created: 2011-12-13 00:48:28+00:00
State: open

If the array is sparse with the last item being undefined the length will be incorrect.
http://jsbin.com/iqamet

~~~ js
_.map(Array(2), function(v) { return v; }).length // should be 2 but in IE < 8 it's 0
~~~