[1.11.x] Fixed #28043 -- Prevented AddIndex and RemoveIndex from mutating model state.

Backport of 63afe3a2bfaf97fecff6641137a85296029d5b73 from master

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/migrations/test_operations.py b/tests/migrations/test_operations.py
index e1daabe8b5..dd8aff4ca8 100644
--- a/tests/migrations/test_operations.py
+++ b/tests/migrations/test_operations.py
@@ -1491,6 +1491,29 @@ class OperationTests(OperationTestBase):
         self.unapply_operations("test_rmin", project_state, operations=operations)
         self.assertIndexExists("test_rmin_pony", ["pink", "weight"])
 
+    def test_add_index_state_forwards(self):
+        project_state = self.set_up_test_model('test_adinsf')
+        index = models.Index(fields=['pink'], name='test_adinsf_pony_pink_idx')
+        old_model = project_state.apps.get_model('test_adinsf', 'Pony')
+        new_state = project_state.clone()
+
+        operation = migrations.AddIndex('Pony', index)
+        operation.state_forwards('test_adinsf', new_state)
+        new_model = new_state.apps.get_model('test_adinsf', 'Pony')
+        self.assertIsNot(old_model, new_model)
+
+    def test_remove_index_state_forwards(self):
+        project_state = self.set_up_test_model('test_rminsf')
+        index = models.Index(fields=['pink'], name='test_rminsf_pony_pink_idx')
+        migrations.AddIndex('Pony', index).state_forwards('test_rminsf', project_state)
+        old_model = project_state.apps.get_model('test_rminsf', 'Pony')
+        new_state = project_state.clone()
+
+        operation = migrations.RemoveIndex('Pony', 'test_rminsf_pony_pink_idx')
+        operation.state_forwards('test_rminsf', new_state)
+        new_model = new_state.apps.get_model('test_rminsf', 'Pony')
+        self.assertIsNot(old_model, new_model)
+
     def test_alter_field_with_index(self):
         """
         Test AlterField operation with an index to ensure indexes created via