madrobby/zepto — pull request #697 by cscott (2013-02-15 22:48:09+00:00)
Title: Deep-copy arrays with $.extend() (fixes gh bug #696)

See the corresponding jQuery code at https://github.com/jquery/jquery/blob/master/src/core.js#L315
where you can see that jQuery handles arrays in a deep copy; zepto currently does not.