1 files changed, 5 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index e21ef90391..f4507c979c 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -8,6 +8,8 @@ module ActiveRecord
       alias_method :new, :build
 
       def create!(attrs = nil)
+        ensure_owner_is_not_new
+
         transaction do
           self << (object = attrs ? @reflection.klass.send(:with_scope, :create => attrs) { @reflection.create_association! } : @reflection.create_association!)
           object
@@ -15,6 +17,8 @@ module ActiveRecord
       end
 
       def create(attrs = nil)
+        ensure_owner_is_not_new
+
         transaction do
           self << (object = attrs ? @reflection.klass.send(:with_scope, :create => attrs) { @reflection.create_association } : @reflection.create_association)
           object
@@ -50,7 +54,7 @@ module ActiveRecord
           options[:select]  = construct_select(options[:select])
           options[:from]  ||= construct_from
           options[:joins]   = construct_joins(options[:joins])
-          options[:include] = @reflection.source_reflection.options[:include] if options[:include].nil?
+          options[:include] = @reflection.source_reflection.options[:include] if options[:include].nil? && @reflection.source_reflection.options[:include]
         end
         
         def insert_record(record, force = true, validate = true)