If a record doesn't qualify to be included in the index on create, it may not be added even if a later update makes it qualify

[chrisbloom7]

Consider the following model:

class Category < ActiveRecord::Base
  acts_as_indexed :fields => [:name, :description], :if => Proc.new { |c| c.products.count > 0 }
  has_many :products
end

If you create a new category that doesn't have any products assigned to it, it won't be included in the index because the :if proc isn't satisfied. If you then later add a product to it and force/trigger the update_index method (changing no other indexed field), it won't be added to the index. This is because ActsAsIndexed::SearchIndex::record_unchanged? will always return true in this case, because when the proc is evaluated on old_record it sees that c.products.count > 0 and the same happens with the proc is evaluated on the old_record - i.e. it is basing the old and new state on the same virtual attribute which isn't ever going to be dirty.

[chrisbloom7]

I did some digging in the source and found that records that aren't originally in the index can be added if they later qualify, but just not in certain circumstances. I updated the issue title and description with a more accurate example.