def plan_rename
      ref = @dao.applied_patches_inverse
      m = {}
      @patches.each do |patch|
        old_name = ref[patch.signature]
        raise NotAppliedError, patch if old_name.nil?
        raise DuplicateError, [patch.name, m[old_name]] if m.key?(old_name)
        m[old_name] = patch.name
      end
      m.select { |old_name, new_name| old_name != new_name }
    end
def plan_rename
      ref = @dao.applied_patches_inverse
      m = {}
      @patches.each do |patch|
        old_name = ref[patch.signature]
        raise NotAppliedError, patch if old_name.nil?
        raise DuplicateError, [patch.name, m[old_name]] if m.key?(old_name)
        m[old_name] = patch.name
      end
      m.select { |old_name, new_name| old_name != new_name }
    end
Produces an { old_name => new_name } hash for mass-renaming.