Single filter with multiple joins use the wrong association alias

[fabioxgn]

I wrote this failing spec:

      it 'evaluates single condition for multiple `belongs_to` associations to the same table' do
        # Why Search.new(Recommendation.joins(:person, :target_person)...) is not the same thing?
        s = Recommendation.joins(:person, :target_person).ransack(
          { target_person_name_eq: 'Test' },
        ).result

        expect(s).to be_an ActiveRecord::Relation

        real_query = remove_quotes_and_backticks(s.to_sql)
        expected_query = <<-SQL
          SELECT recommendations.* FROM recommendations
          INNER JOIN people ON people.id = recommendations.person_id
          INNER JOIN people target_people_recommendations
            ON target_people_recommendations.id = recommendations.target_person_id
          WHERE target_people_recommendations.name = 'Test'
        SQL
        .squish

        expect(real_query).to eq expected_query
      end

It results in:

WHERE people.name = 'Test'"

Instead of:

WHERE target_people_recommendations.name = 'Test'"

And it only happens if there isn't a filter on the other table, If I write what the existing spec is testing:

s = Recommendation.joins(:person, :target_person).ransack(
  { person_name_eq: 'Ernie', target_person_name_eq: 'Test' },
).result

Then it works as expected:

WHERE (people.name = 'Ernie' AND target_people_recommendations.name = 'Test')"

This looks like a bug to me, I have one query that I need to join the same table twice, and this is getting the wrong results. I'm joining both tables because I'm selecting specific columns from both tables, but I need to filter by the aliased one.