diff options
Diffstat (limited to 'django/db/models/query.py')
| -rw-r--r-- | django/db/models/query.py | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/django/db/models/query.py b/django/db/models/query.py index 22919e504e..dca6eea1ba 100644 --- a/django/db/models/query.py +++ b/django/db/models/query.py @@ -1910,6 +1910,14 @@ def prefetch_one_level(instances, prefetcher, lookup, level): instance_attr_val = instance_attr(obj) vals = rel_obj_cache.get(instance_attr_val, []) to_attr, as_attr = lookup.get_current_to_attr(level) + + # Check we are not shadowing a field on obj. + if as_attr: + for related_m2m in obj._meta.get_all_related_many_to_many_objects(): + if related_m2m.get_accessor_name() == to_attr: + msg = 'to_attr={} conflicts with a field on the {} model.' + raise ValueError(msg.format(to_attr, obj.__class__.__name__)) + if single: val = vals[0] if vals else None to_attr = to_attr if as_attr else cache_name |