Dependency graph is overwritten in some scenarios

The dependency graph is being overwritten when a question (within a group) has two conditions that reference the same question.

In the scenario below, both "What is his name?" and "How old is he?" should show when "Do you own a dog?" is "Yes". Only "How old is he?" shows though because the dependency graph is overwritten.

<pre>
survey "Double Dependency" do
  section "One" do
    group "" do
      q_dog "Do you own a dog?", :pick => :one
      a_yes "Yes"
      a_no  "No"

      q "What is his name?"
      a :string
      dependency :rule=>"A"
      condition_A :q_dog, "==", :a_yes

      q "How old is he?"
      a :integer
      dependency :rule=>"A and B"
      condition_A :q_dog, "count>0"
      condition_B :q_dog, "!=", :a_no
    end
  end
end
</pre>