Rails has_many :through regression

has_many.rb

class Order
  has_many :order_tickets
  has_many :tickets, :through => :order_tickets
end

class Ticket
  has_many :order_tickets
  has_many :orders, :through => :order_tickets
end

class OrderTicket
  belongs_to :order
  belongs_to :ticket
end


ticket = Ticket.create :name => "Standard"

order = Order.create

order.tickets = [ ticket, ticket, ticket ] 

order.tickets.reload.count => 1

# works for different tickets like :name => Standard // Student // Guset 
# so it behaves as if :uniq => true was set. 
# Worked in rails 3.0.7-3.0.10 but not in rails 3.1.0

# In rails 3.0.x it would return
# o.reload.tickets => [ <Ticket id: 1 …>, <Ticket id: 1 …>, <Ticket id: 1 …>] 

# Now only 
# o.reload.tickets => [ <Ticket id: 1 …>]