Fixed #36847 -- Ensured auto_now_add fields are set on pre_save().

Regression in 94680437a45a71c70ca8bd2e68b72aa1e2eff337. Refs #27222.

During INSERT operations, `field.pre_save()` is called to prepare values
for db insertion. The `add` param must be `True` for `auto_now_add`
fields to be populated. The regression commit passed `False`, causing
`auto_now_add` fields to remain `None` when used by other fields, such
as `upload_to` callables.

Thanks Ran Benita for the report.

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/model_fields/models.py b/tests/model_fields/models.py
index 1d8a447dee..a594b89adb 100644
--- a/tests/model_fields/models.py
+++ b/tests/model_fields/models.py
@@ -262,10 +262,20 @@ class DataModel(models.Model):
 # FileField
 
 
+def upload_to_with_date(instance, filename):
+    return f"{instance.created_at.year}/{filename}"
+
+
 class Document(models.Model):
     myfile = models.FileField(storage=temp_storage, upload_to="unused", unique=True)
 
 
+# See ticket #36847.
+class DocumentWithTimestamp(models.Model):
+    created_at = models.DateTimeField(auto_now_add=True)
+    myfile = models.FileField(storage=temp_storage, upload_to=upload_to_with_date)
+
+
 ###############################################################################
 # ImageField