From c0beff21239e70cbdcc9597e5be09e505bb8f76c Mon Sep 17 00:00:00 2001
From: Fiza Ashraf <68822806+fizaashraf37@users.noreply.github.com>
Date: Sat, 6 Aug 2022 13:51:43 -0700
Subject: [PATCH] Fixed #33899 -- Fixed migration crash when removing indexed
 field on SQLite 3.35.5+.
Regression in 702819227fd0cdd9b581cd99e11d1561d51cbeb.
Thanks cessor for the report.
---
 AUTHORS                              |  1 +
 django/db/backends/sqlite3/schema.py |  5 +++--
 docs/releases/4.1.1.txt              |  3 +++
 tests/schema/tests.py                | 11 +++++++++++
 4 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/AUTHORS b/AUTHORS
index 356680682a..48359498f6 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -322,6 +322,7 @@ answer newbie questions, and generally made Django that much better:
     Filip Noetzel 
     Filip Wasilewski 
     Finn Gruwier Larsen 
+    Fiza Ashraf 
     Flávio Juvenal da Silva Junior 
     flavio.curella@gmail.com
     Florian Apolloner 
diff --git a/django/db/backends/sqlite3/schema.py b/django/db/backends/sqlite3/schema.py
index 55fdf5fbfe..6c106ae868 100644
--- a/django/db/backends/sqlite3/schema.py
+++ b/django/db/backends/sqlite3/schema.py
@@ -408,10 +408,11 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
             # For explicit "through" M2M fields, do nothing
         elif (
             self.connection.features.can_alter_table_drop_column
-            # Primary keys, unique fields, and foreign keys are not
-            # supported in ALTER TABLE DROP COLUMN.
+            # Primary keys, unique fields, indexed fields, and foreign keys are
+            # not supported in ALTER TABLE DROP COLUMN.
             and not field.primary_key
             and not field.unique
+            and not field.db_index
             and not (field.remote_field and field.db_constraint)
         ):
             super().remove_field(model, field)
diff --git a/docs/releases/4.1.1.txt b/docs/releases/4.1.1.txt
index 7339390ffa..2e61e3877d 100644
--- a/docs/releases/4.1.1.txt
+++ b/docs/releases/4.1.1.txt
@@ -26,3 +26,6 @@ Bugfixes
 * Fixed a regression in Django 4.1 that caused a crash of
   :class:`~django.db.models.expressions.Window` expressions with
   :class:`~django.contrib.postgres.aggregates.ArrayAgg` (:ticket:`33898`).
+
+* Fixed a regression in Django 4.1 that caused a migration crash on SQLite
+  3.35.5+ when removing an indexed field (:ticket:`33899`).
diff --git a/tests/schema/tests.py b/tests/schema/tests.py
index 0702b54135..a72e6906bb 100644
--- a/tests/schema/tests.py
+++ b/tests/schema/tests.py
@@ -813,6 +813,17 @@ class SchemaTests(TransactionTestCase):
                 False,
             )
 
+    def test_remove_indexed_field(self):
+        with connection.schema_editor() as editor:
+            editor.create_model(AuthorCharFieldWithIndex)
+        with connection.schema_editor() as editor:
+            editor.remove_field(
+                AuthorCharFieldWithIndex,
+                AuthorCharFieldWithIndex._meta.get_field("char_field"),
+            )
+        columns = self.column_classes(AuthorCharFieldWithIndex)
+        self.assertNotIn("char_field", columns)
+
     def test_alter(self):
         """
         Tests simple altering of fields