Fix category modification on amendment submission.

1 files changed, 7 insertions, 2 deletions

diff --git a/chimere/admin.py b/chimere/admin.py
index ff689af..4e175aa 100644
--- a/chimere/admin.py
+++ b/chimere/admin.py
@@ -118,8 +118,13 @@ def managed_modified(modeladmin, request, queryset):
                 if not request.POST[k]:
                     continue
                 if hasattr(it_ref, k):
-                    setattr(it_ref, k, getattr(it, k))
-                    it_ref.save()
+                    c_value = getattr(it_ref, k)
+                    if hasattr(c_value, 'select_related'):
+                        c_value.clear()
+                        for val in getattr(it, k).all():
+                            c_value.add(val)
+                    else:
+                        it_ref.save()
                 elif k.startswith('property_'):
                     try:
                         pm = PropertyModel.get(pk=int(k[len('property_'):]))