associations.rb

              def aliased_table_name_for(name, suffix = nil)
                if !parent.table_joins.blank? && parent.table_joins.to_s.downcase =~ %r{join(\s+\w+)?\s+#{active_record.connection.quote_table_name name.downcase}\son}
                  @join_dependency.table_aliases[name] += 1
                end

                unless @join_dependency.table_aliases[name].zero?
                  # if the table name has been used, then use an alias
                  name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}"
                  table_index = @join_dependency.table_aliases[name]
                  @join_dependency.table_aliases[name] += 1
                  name = name[0..active_record.connection.table_alias_length-3] + "_#{table_index+1}" if table_index > 0
                else
                  @join_dependency.table_aliases[name] += 1
                end

                name
              end