PR: https://github.com/mongodb/mongoid/pull/5012

Since #4817 find can take a block, however this is not used when a has many relation proxy is used. This is a simple change to allow the block to be passed through to the criteria.

Example:

class Widget 
  include Mongoid::Document
  has_many :screws

  def find_flat_screw 
    screws.find { |screw| screw.head == 'flat' } 
  end
end

The find method above will currently return an empty set incorrectly, instead of the first item in the has_many collection