mongodb/mongo — pull request #220 by jpfarias (2012-05-01 22:24:00+00:00)
Title: [MongoDB-JIRA] (SERVER-1014) Allow $pop modifier to remove by index.

This will allow $pop modifier to remove by index.

To keep compatibility with the previous $pop, using -N will remove from
front and N will remove from back. If the absolute value of N is
greater than the array size then the array won't be modified.