Fixed #34176 -- Fixed grouping by ambiguous aliases.

Regression in b7b28c7c18.

Refs #31377.

Thanks Shai Berger for the report and reviews.

test_aggregation_subquery_annotation_values_collision() has been
updated as queries that are explicitly grouped by a subquery should
always be grouped by it and not its outer columns even if its alias
collides with referenced table columns. This was not possible to
accomplish at the time 10866a10 landed because we didn't have compiler
level handling of colliding aliases.

tests/aggregation_regress/tests.py

@@ -11,6 +11,7 @@ from django.db.models import (
     Aggregate,
     Avg,
     Case,
+    CharField,
     Count,
     DecimalField,
     F,
@@ -23,12 +24,15 @@ from django.db.models import (
     Variance,
     When,
 )
+from django.db.models.functions import Cast, Concat
 from django.test import TestCase, skipUnlessDBFeature
 from django.test.utils import Approximate
 
 from .models import (
     Alfa,
     Author,
+    AuthorProxy,
+    AuthorUnmanaged,
     Book,
     Bravo,
     Charlie,
@@ -37,6 +41,8 @@ from .models import (
     HardbackBook,
     ItemTag,
     Publisher,
+    RecipeProxy,
+    RecipeUnmanaged,
     SelfRefFK,
     Store,
     WithManualPK,
@@ -188,9 +194,8 @@ class AggregationTests(TestCase):
                     }
                 ],
             )
-        if connection.features.allows_group_by_refs:
-            alias = connection.ops.quote_name("discount_price")
-            self.assertIn(f"GROUP BY {alias}", ctx[0]["sql"])
+        if connection.features.allows_group_by_select_index:
+            self.assertIn("GROUP BY 1", ctx[0]["sql"])
 
     def test_aggregates_in_where_clause(self):
         """
@@ -1827,6 +1832,85 @@ class AggregationTests(TestCase):
         )
         self.assertEqual(set(books), {self.b1, self.b4})
 
+    def test_aggregate_and_annotate_duplicate_columns(self):
+        books = (
+            Book.objects.values("isbn")
+            .annotate(
+                name=F("publisher__name"),
+                num_authors=Count("authors"),
+            )
+            .order_by("isbn")
+        )
+        self.assertSequenceEqual(
+            books,
+            [
+                {"isbn": "013235613", "name": "Prentice Hall", "num_authors": 3},
+                {"isbn": "013790395", "name": "Prentice Hall", "num_authors": 2},
+                {"isbn": "067232959", "name": "Sams", "num_authors": 1},
+                {"isbn": "155860191", "name": "Morgan Kaufmann", "num_authors": 1},
+                {"isbn": "159059725", "name": "Apress", "num_authors": 2},
+                {"isbn": "159059996", "name": "Apress", "num_authors": 1},
+            ],
+        )
+
+    def test_aggregate_and_annotate_duplicate_columns_proxy(self):
+        author = AuthorProxy.objects.latest("pk")
+        recipe = RecipeProxy.objects.create(name="Dahl", author=author)
+        recipe.tasters.add(author)
+        recipes = RecipeProxy.objects.values("pk").annotate(
+            name=F("author__name"),
+            num_tasters=Count("tasters"),
+        )
+        self.assertSequenceEqual(
+            recipes,
+            [{"pk": recipe.pk, "name": "Stuart Russell", "num_tasters": 1}],
+        )
+
+    def test_aggregate_and_annotate_duplicate_columns_unmanaged(self):
+        author = AuthorProxy.objects.latest("pk")
+        recipe = RecipeProxy.objects.create(name="Dahl", author=author)
+        recipe.tasters.add(author)
+        recipes = RecipeUnmanaged.objects.values("pk").annotate(
+            name=F("author__age"),
+            num_tasters=Count("tasters"),
+        )
+        self.assertSequenceEqual(
+            recipes,
+            [{"pk": recipe.pk, "name": 46, "num_tasters": 1}],
+        )
+
+    def test_aggregate_group_by_unseen_columns_unmanaged(self):
+        author = AuthorProxy.objects.latest("pk")
+        shadow_author = AuthorProxy.objects.create(name=author.name, age=author.age - 2)
+        recipe = RecipeProxy.objects.create(name="Dahl", author=author)
+        shadow_recipe = RecipeProxy.objects.create(
+            name="Shadow Dahl",
+            author=shadow_author,
+        )
+        recipe.tasters.add(shadow_author)
+        shadow_recipe.tasters.add(author)
+        # This selects how many tasters each author had according to a
+        # calculated field "name". The table has a column "name" that Django is
+        # unaware of, and is equal for the two authors. The grouping column
+        # cannot be referenced by its name ("name"), as it'd return one result
+        # which is incorrect.
+        author_recipes = (
+            AuthorUnmanaged.objects.annotate(
+                name=Concat(
+                    Value("Writer at "),
+                    Cast(F("age"), output_field=CharField()),
+                )
+            )
+            .values("name")  # Field used for grouping.
+            .annotate(num_recipes=Count("recipeunmanaged"))
+            .filter(num_recipes__gt=0)
+            .values("num_recipes")  # Drop grouping column.
+        )
+        self.assertSequenceEqual(
+            author_recipes,
+            [{"num_recipes": 1}, {"num_recipes": 1}],
+        )
+
 
 class JoinPromotionTests(TestCase):
     def test_ticket_21150(self):