Attempt to fix issue #402 #402

activerecord/lib/active_record/associations.rb

@@ -1706,14 +1706,14 @@ def #{method_name}
         end
 
         def configure_after_destroy_method_for_has_and_belongs_to_many(reflection)
-          method_name = :"has_and_belongs_to_many_after_destroy_for_#{reflection.name}"
+          method_name = :"has_and_belongs_to_many_before_destroy_for_#{reflection.name}"
           class_eval <<-eoruby, __FILE__, __LINE__ + 1
             def #{method_name}
               association = #{reflection.name}
               association.delete_all if association
             end
           eoruby
-          after_destroy method_name
+          before_destroy method_name
         end
 
         def delete_all_has_many_dependencies(record, reflection_name, association_class, dependent_conditions)

activerecord/test/cases/habtm_destroy_order_test.rb

@@ -16,6 +16,19 @@ class HabtmDestroyOrderTest < ActiveRecord::TestCase
     assert !sicp.destroyed?
   end
 
+  test 'may not raise error if have foreign key in the join table' do
+    # TODO: Using foreign keys. Add conditionals if need to around dbs that support it.
+    Lesson.connection.execute  "ALTER TABLE lessons_students ADD CONSTRAINT lesson_id_fk FOREIGN KEY (lesson_id) REFERENCES  lessons(id)"
+    Student.connection.execute "ALTER TABLE lessons_students ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students(id)"
+    student = Student.new(:name => "Ben Bitdiddle")
+    lesson = Lesson.new(:name => "SICP")
+    lesson.students << student
+    lesson.save!
+    assert_nothing_raised do
+      student.destroy
+    end
+  end
+
   test "not destroying a student with lessons leaves student<=>lesson association intact" do
     # test a normal before_destroy doesn't destroy the habtm joins
     begin