UnionOfRAD/lithium — pull request #769 by coogle (2012-12-26 19:47:49+00:00)
Title: Doing a recursive unset of _id fields in the DB exporter, as MongoDB

doesn't let you use $set and modify _id. So if you have a document that has a sub-object and that object also has a _id field, the existing implementation breaks because it only considers the top-level _id key. This patch recursively traverses the data and removes all _id key references during an update.