handle self-references

fkreplace/__init__.py

@@ -31,10 +31,14 @@ def merge(from_obj, to_obj):
 
     for related in from_obj._meta.get_all_related_many_to_many_objects():
         accessor_name = related.get_accessor_name()
-        if accessor_name:
-            varname = related.field.name
-            field = getattr(from_obj, accessor_name)
-            if related.many_to_many:
-                for f in field.all():
-                    getattr(f, varname).remove(from_obj)
-                    getattr(f, varname).add(to_obj)
+        varname = related.field.name
+
+        if not accessor_name:
+            # not set in M2M to self, but varname will match
+            accessor_name = varname
+
+        field = getattr(from_obj, accessor_name)
+        if related.many_to_many:
+            for f in field.all():
+                getattr(f, varname).remove(from_obj)
+                getattr(f, varname).add(to_obj)

tests/tests.py

@@ -68,4 +68,4 @@ class MergeTests(TestCase):
         merge(self.a, self.b)
         assert self.a.friends.all().count() == 0
         assert self.b.friends.get().name == f.name
-        assert f.get().name == self.b.name
+        assert f.friends.get().name == self.b.name