ActiveRecord 4.0.5 behaves unexpectedly when has-many relationship and `where_values` are used in the same query.

ar_buggy_beahvior.rb

require 'active_record'
require 'sqlite3'

prepare = <<SQL
create table viewers (
  id integer primary key autoincrement, name, created_at, updated_at
);
create table notes (
  id integer primary key autoincrement, name, created_at, updated_at
);
create table note_viewers (
  id integer primary key autoincrement, viewer_id, note_id, created_at, updated_at
);
SQL
unless File.exist?('test.sqlite3')
  IO.popen('sqlite3 test.sqlite3', 'r+') do |io|
    io.write prepare
    io.close_write
    puts io.gets
  end
end

ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: 'test.sqlite3')

class Viewer < ActiveRecord::Base
  has_many :note_viewers
  has_many :notes, through: :note_viewers
end

class Note < ActiveRecord::Base
  has_many :note_viewers
  has_many :viewers, through: :note_viewers

  scope :name_1, lambda { where(name: 'note1') }
  scope :name_2, lambda { where(name: 'note2') }
  scope :interested, lambda {
    l = name_1.where_values.reduce(:and) # THIS IS PROBLEM: where_values contains already applied viewer_id scoping
    r = name_2.where_values.reduce(:and)
    where(l.or(r))
  }
end

class NoteViewer < ActiveRecord::Base
  belongs_to :note
  belongs_to :viewer
end

note1 = Note.create!(name: 'note1')
viewer1 = Viewer.create!(name: 'viewer1')
NoteViewer.create!(note: note1, viewer: viewer1)
puts viewer1.notes.interested.to_sql
# => SELECT "notes".* FROM "notes" INNER JOIN "note_viewers" ON "notes"."id" = "note_viewers"."note_id" WHERE "note_viewers"."viewer_id" = ? AND (("note_viewers"."viewer_id" = ? AND "notes"."name" = 'note1' OR "note_viewers"."viewer_id" = ? AND "notes"."name" = 'note2'))

p viewer1.notes.interested.count # => 0 ???
 
raw_connection = ActiveRecord::Base.connection.raw_connection
st = raw_connection.prepare(viewer1.notes.interested.to_sql)
st.execute(viewer1.id, viewer1.id, viewer1.id) do |result|
  p result.count # => 1
end