documentcloud/backbone — pull request #1076 by braddunbar (2012-03-07 16:37:44+00:00)
Title: Fix #1074 - set/clear/unset do not alter options.

Conceptually, this patch certainly fixes the issue put forth in #1074. However, there is a [significant performance cost](jsperf) of approximately 30% associated with it. I've also been bitten by this type of bug before so I understand the desire to prevent it but 30% is a rather steep price to pay for it.

[jsperf]: http://jsperf.com/cloning-arguments