Merge pull request mbleigh#367 from rsl/master

Fixed bug with Rails 4 and association#to_sql

lib/acts_as_taggable_on/acts_as_taggable_on/collection.rb

@@ -87,9 +87,9 @@ def all_tags(options = {})
 
         # Append the current scope to the scope, because we can't use scope(:find) in RoR 3.0 anymore:
         scoped_select = "#{table_name}.#{primary_key}"
-        tagging_scope = tagging_scope.where("#{ActsAsTaggableOn::Tagging.table_name}.taggable_id IN(#{select(scoped_select).to_sql})").group(group_columns)
+        tagging_scope = tagging_scope.where("#{ActsAsTaggableOn::Tagging.table_name}.taggable_id IN(#{safe_to_sql(select(scoped_select))})").group(group_columns)
 
-        tag_scope = tag_scope.joins("JOIN (#{tagging_scope.to_sql}) AS #{ActsAsTaggableOn::Tagging.table_name} ON #{ActsAsTaggableOn::Tagging.table_name}.tag_id = #{ActsAsTaggableOn::Tag.table_name}.id")
+        tag_scope = tag_scope.joins("JOIN (#{safe_to_sql(tagging_scope)}) AS #{ActsAsTaggableOn::Tagging.table_name} ON #{ActsAsTaggableOn::Tagging.table_name}.tag_id = #{ActsAsTaggableOn::Tag.table_name}.id")
         tag_scope
       end
 
@@ -164,14 +164,18 @@ def all_tag_counts(options = {})
         unless options[:id]
           # Append the current scope to the scope, because we can't use scope(:find) in RoR 3.0 anymore:
           scoped_select = "#{table_name}.#{primary_key}"
-          tagging_scope = tagging_scope.where("#{ActsAsTaggableOn::Tagging.table_name}.taggable_id IN(#{select(scoped_select).to_sql})")
+          tagging_scope = tagging_scope.where("#{ActsAsTaggableOn::Tagging.table_name}.taggable_id IN(#{safe_to_sql(select(scoped_select))})")
         end
 
         tagging_scope = tagging_scope.group(group_columns).having(having)
 
-        tag_scope = tag_scope.joins("JOIN (#{tagging_scope.to_sql}) AS #{ActsAsTaggableOn::Tagging.table_name} ON #{ActsAsTaggableOn::Tagging.table_name}.tag_id = #{ActsAsTaggableOn::Tag.table_name}.id")
+        tag_scope = tag_scope.joins("JOIN (#{safe_to_sql(tagging_scope)}) AS #{ActsAsTaggableOn::Tagging.table_name} ON #{ActsAsTaggableOn::Tagging.table_name}.tag_id = #{ActsAsTaggableOn::Tag.table_name}.id")
         tag_scope
       end
+
+      def safe_to_sql(relation)
+        connection.respond_to?(:unprepared_statement) ? connection.unprepared_statement{relation.to_sql} : relation.to_sql
+      end
     end
 
     module InstanceMethods