Ticket #2579: fix_raw_id_admin_m2m.patch

django/db/models/manipulators.py

@@ -118 +118 @@
                 if not f.rel.edit_inline:
                     if f.rel.raw_id_admin:
                         new_vals = new_data.get(f.name, ())
+                        # Not handling 'empty' raw_id_admin fields properly
+                        # If nothing was entered, skip the rel manager add 
+                        if len(new_vals) == 1 and '' == new_vals[0]:
+                            continue
                     else:
                         new_vals = new_data.getlist(f.name)
                     # First, clear the existing values.