Fixed #32095 -- Made QuerySet.update_or_create() save only fields passed in defaults or with custom pre_save().

Thanks Florian Apolloner for the initial patch.

django/db/models/query.py

@@ -20,7 +20,7 @@ from django.db import (
     router,
     transaction,
 )
-from django.db.models import AutoField, DateField, DateTimeField, sql
+from django.db.models import AutoField, DateField, DateTimeField, Field, sql
 from django.db.models.constants import LOOKUP_SEP, OnConflict
 from django.db.models.deletion import Collector
 from django.db.models.expressions import Case, F, Ref, Value, When
@@ -963,7 +963,25 @@ class QuerySet:
                 return obj, created
             for k, v in resolve_callables(defaults):
                 setattr(obj, k, v)
-            obj.save(using=self.db)
+
+            update_fields = set(defaults)
+            concrete_field_names = self.model._meta._non_pk_concrete_field_names
+            # update_fields does not support non-concrete fields.
+            if concrete_field_names.issuperset(update_fields):
+                # Add fields which are set on pre_save(), e.g. auto_now fields.
+                # This is to maintain backward compatibility as these fields
+                # are not updated unless explicitly specified in the
+                # update_fields list.
+                for field in self.model._meta.local_concrete_fields:
+                    if not (
+                        field.primary_key or field.__class__.pre_save is Field.pre_save
+                    ):
+                        update_fields.add(field.name)
+                        if field.name != field.attname:
+                            update_fields.add(field.attname)
+                obj.save(using=self.db, update_fields=update_fields)
+            else:
+                obj.save(using=self.db)
         return obj, False
 
     async def aupdate_or_create(self, defaults=None, **kwargs):