Fix refresh_from_db for ConcurrentTransitionMixin. Close #255

Author: kmmbvnr

django_fsm/__init__.py

@@ -512,6 +512,10 @@ def _update_initial_state(self):
             (field.attname, field.value_from_object(self)) for field in self.state_fields
         )
 
+    def refresh_from_db(self, *args, **kwargs):
+        super(ConcurrentTransitionMixin, self).refresh_from_db(*args, **kwargs)
+        self._update_initial_state()
+    
     def save(self, *args, **kwargs):
         super(ConcurrentTransitionMixin, self).save(*args, **kwargs)
         self._update_initial_state()

tests/testapp/tests/test_lock_mixin.py

@@ -4,7 +4,7 @@
 
 
 class LockedBlogPost(ConcurrentTransitionMixin, models.Model):
-    state = FSMField(default='new', protected=True)
+    state = FSMField(default='new')
     text = models.CharField(max_length=50)
 
     @transition(field=state, source='new', target='published')
@@ -60,7 +60,7 @@ def test_save_and_change_succeed(self):
 
         post.delete()
 
-    def test_concurent_modifications_raise_exception(self):
+    def test_concurrent_modifications_raise_exception(self):
         post1 = LockedBlogPost.objects.create()
         post2 = LockedBlogPost.objects.get(pk=post1.pk)
 
@@ -86,3 +86,14 @@ def test_inheritance_crud_succeed(self):
         post = ExtendedBlogPost.objects.get(pk=post.pk)
         self.assertEqual('rejected', post.review_state)
         self.assertEqual('test_inheritance_crud_succeed2', post.text)
+
+    def test_concurrent_modifications_after_refresh_db_succeed(self):  # bug 255
+        post1 = LockedBlogPost.objects.create()
+        post2 = LockedBlogPost.objects.get(pk=post1.pk)
+
+        post1.publish()
+        post1.save()
+
+        post2.refresh_from_db()
+        post2.remove()
+        post2.save()