Fixed #35127 -- Made Model.full_clean() ignore GeneratedFields.

[felixxm]

Thanks Claude Paroz for the report.

Regression in f333e35.

ticket-35127

[shangxiao]

Nice quick fix ⭐

We've seen this pop up once before, I was almost going to suggest defining something alongside fields in a similar spirit to concrete_fields though not sure it's worth it.

Are there any more instances of accessing fields that we should check or have you checked already?

[claudep]

Thanks for the quick fix!

[felixxm]

Thanks both for checking 👍

We've seen this pop up once before, I was almost going to suggest defining something alongside fields in a similar spirit to concrete_fields though not sure it's worth it.

Yes, there are a few places, but I don't think it's worth adding concrete_non_generated_fields. Maybe later on the main as a cleanup.

Are there any more instances of accessing fields that we should check or have you checked already?

I'll check other places, but even If I find something, it will be a separate bug.

[charettes]

I wonder if this is a missed opportunity to branch of field.editable instead.

Per the docs these should be skipped during model validation. Is it not the case?

[felixxm]

I wonder if this is a missed opportunity to branch of field.editable instead.

Per the docs these should be skipped during model validation. Is it not the case?

I don't think that would work 🤔, because AttributeError is raised when getting a value for deferred generated fields and clean() will still try to do this even when we early return from validate().

[charettes]

@felixxm what I meant is something like that

diff --git a/django/db/models/base.py b/django/db/models/base.py
index 61925f63ea..ec0e975837 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -1628,7 +1628,7 @@ def clean_fields(self, exclude=None):

         errors = {}
         for f in self._meta.fields:
-            if f.name in exclude or f.generated:
+            if f.name in exclude or not f.editable:
                 continue
             # Skip validation for empty fields with blank=True. The developer
             # is responsible for making sure they have a valid value.

which seems more correct based on the Field.editable documentation

They are also skipped during model validation.

And happens to resolve this issue as GeneratedField.editable must be set to False.

FWIW the full test suite passes on SQLite except for model_fields.test_binaryfield.BinaryFieldTests.test_max_length which seems to be violating the documentation.

[felixxm]

@felixxm what I meant is something like that

Right 👍 We can change this on the main branch (as a separate cleanup) since it breaks some tests.

[charettes]

Agreed likely safer, I'll create a ticket about it and target main. Thanks for the discussion.