Move from select * to select tablename.* to avoid clobbering IDs. Closes #8889 [dasil003]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7167 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb

@@ -53,6 +53,7 @@ module ActiveRecord
           options[:conditions] = conditions
           options[:joins]      = @join_sql
           options[:readonly]   = finding_with_ambigious_select?(options[:select])
+          options[:select]   ||= '*'
 
           if options[:order] && @reflection.options[:order]
             options[:order] = "#{options[:order]}, #{@reflection.options[:order]}"

activerecord/lib/active_record/base.rb

@@ -1109,7 +1109,7 @@ module ActiveRecord #:nodoc:
 
         def construct_finder_sql(options)
           scope = scope(:find)
-          sql  = "SELECT #{(scope && scope[:select]) || options[:select] || '*'} "
+          sql  = "SELECT #{(scope && scope[:select]) || options[:select] || (options[:joins] && table_name + '.*') || '*'} "
           sql << "FROM #{(scope && scope[:from]) || options[:from] || table_name} "
 
           add_joins!(sql, options, scope)