1 files changed, 6 insertions, 0 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 acac68fda5..9d2b29685b 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -34,7 +34,9 @@ module ActiveRecord
       end
 
       def insert_record(record, validate = true)
+        ensure_not_nested
         return if record.new_record? && !record.save(:validate => validate)
+
         through_record(record).save!
         update_counter(1)
         record
@@ -59,6 +61,8 @@ module ActiveRecord
         end
 
         def build_record(attributes)
+          ensure_not_nested
+
           record = super(attributes)
 
           inverse = source_reflection.inverse_of
@@ -93,6 +97,8 @@ module ActiveRecord
         end
 
         def delete_records(records, method)
+          ensure_not_nested
+
           through = owner.association(through_reflection.name)
           scope   = through.scoped.where(construct_join_attributes(*records))