Fixed #34529, Refs #34525 -- Reduced index operations with Meta.indexes/index_together when optimizing migrations.

This makes squashing migrations an available path for changing
Meta.index_together, which is deprecated, to Meta.indexes.

Follow up to f81032572107846922745b68d5b7191058fdd5f5.

1 files changed, 65 insertions, 0 deletions

diff --git a/django/db/migrations/operations/models.py b/django/db/migrations/operations/models.py
index b89b6b511b..9c5bd5fbcb 100644
--- a/django/db/migrations/operations/models.py
+++ b/django/db/migrations/operations/models.py
@@ -303,6 +303,71 @@ class CreateModel(ModelOperation):
                         managers=self.managers,
                     ),
                 ]
+        elif (
+            isinstance(operation, IndexOperation)
+            and self.name_lower == operation.model_name_lower
+        ):
+            if isinstance(operation, AddIndex):
+                return [
+                    CreateModel(
+                        self.name,
+                        fields=self.fields,
+                        options={
+                            **self.options,
+                            "indexes": [
+                                *self.options.get("indexes", []),
+                                operation.index,
+                            ],
+                        },
+                        bases=self.bases,
+                        managers=self.managers,
+                    ),
+                ]
+            elif isinstance(operation, RemoveIndex):
+                options_indexes = [
+                    index
+                    for index in self.options.get("indexes", [])
+                    if index.name != operation.name
+                ]
+                return [
+                    CreateModel(
+                        self.name,
+                        fields=self.fields,
+                        options={
+                            **self.options,
+                            "indexes": options_indexes,
+                        },
+                        bases=self.bases,
+                        managers=self.managers,
+                    ),
+                ]
+            elif isinstance(operation, RenameIndex) and operation.old_fields:
+                options_index_together = {
+                    fields
+                    for fields in self.options.get("index_together", [])
+                    if fields != operation.old_fields
+                }
+                if options_index_together:
+                    self.options["index_together"] = options_index_together
+                else:
+                    self.options.pop("index_together", None)
+                return [
+                    CreateModel(
+                        self.name,
+                        fields=self.fields,
+                        options={
+                            **self.options,
+                            "indexes": [
+                                *self.options.get("indexes", []),
+                                models.Index(
+                                    fields=operation.old_fields, name=operation.new_name
+                                ),
+                            ],
+                        },
+                        bases=self.bases,
+                        managers=self.managers,
+                    ),
+                ]
         return super().reduce(operation, app_label)