`move :below` fails

[FND]

test case: https://github.com/FND/dm-is-list/compare/below_bug

the first .move :below fails - yet it succeeds if first doing an arbitrary .move :above

Since the RSpec test case seems potentially confusing, here's a sample script that might make it clearer:

module DEBUG

  def self.info
    puts Animal.all(:order => :position.asc).map(&:id).join("  ")
  end

  def self.move(id, vector, ref_id)
    puts Animal.get!(id).move vector => Animal.get!(ref_id)
  end

end

5.times do |i|
  name = "animal#{i}"
  Animal.create
end

DEBUG::info # 1  2  3  4  5
DEBUG::move 5, :below, 1 # false
DEBUG::info # 1  2  3  4  5
DEBUG::move 5, :above, 1 # true
DEBUG::info # 5  1  2  3  4
DEBUG::move 5, :below, 1 # true
DEBUG::info # 1  5  2  3  4

[rdvdijk]

I've just noticed this as well. The bug in the code is fairly obvious. See here how the newpos (new position of the item to be moved) is determined:

          when :below
            # the object given, can either be:
            # -- the same as self
            # -- already above self
            # -- lower than self (higher number in list)
            ( self == object or (object.position < self.position) ) ? self.position : object.position + 1

So: Keep the same position if the object is itself, or if the object is already anywhere below this position. I'll try and fix this and propose a pull request.

[rdvdijk]

I've fixed this and created a pull request for it.