Fixed #35257 -- Corrected resolving output_field for IntegerField/DecimalField with NULL.

django/db/models/expressions.py

@@ -5,6 +5,7 @@ import inspect
 from collections import defaultdict
 from decimal import Decimal
 from enum import Enum
+from itertools import chain
 from types import NoneType
 from uuid import UUID
 
@@ -597,10 +598,16 @@ _connector_combinations = [
     },
     # Numeric with NULL.
     {
-        connector: [
-            (field_type, NoneType, field_type),
-            (NoneType, field_type, field_type),
-        ]
+        connector: list(
+            chain.from_iterable(
+                [(field_type, NoneType, field_type), (NoneType, field_type, field_type)]
+                for field_type in (
+                    fields.IntegerField,
+                    fields.DecimalField,
+                    fields.FloatField,
+                )
+            )
+        )
         for connector in (
             Combinable.ADD,
             Combinable.SUB,
@@ -609,7 +616,6 @@ _connector_combinations = [
             Combinable.MOD,
             Combinable.POW,
         )
-        for field_type in (fields.IntegerField, fields.DecimalField, fields.FloatField)
     },
     # Date/DateTimeField/DurationField/TimeField.
     {

tests/expressions/tests.py

@@ -2654,6 +2654,29 @@ class CombinedExpressionTests(SimpleTestCase):
                 with self.assertRaisesMessage(FieldError, msg):
                     expr.output_field
 
+    def test_resolve_output_field_numbers_with_null(self):
+        test_values = [
+            (3.14159, None, FloatField),
+            (None, 3.14159, FloatField),
+            (None, 42, IntegerField),
+            (42, None, IntegerField),
+            (None, Decimal("3.14"), DecimalField),
+            (Decimal("3.14"), None, DecimalField),
+        ]
+        connectors = [
+            Combinable.ADD,
+            Combinable.SUB,
+            Combinable.MUL,
+            Combinable.DIV,
+            Combinable.MOD,
+            Combinable.POW,
+        ]
+        for lhs, rhs, expected_output_field in test_values:
+            for connector in connectors:
+                with self.subTest(lhs=lhs, connector=connector, rhs=rhs):
+                    expr = CombinedExpression(Value(lhs), connector, Value(rhs))
+                    self.assertIsInstance(expr.output_field, expected_output_field)
+
     def test_resolve_output_field_dates(self):
         tests = [
             # Add - same type.