Permalink
Browse files

[1.7.x] Revert "Fixed #23474 -- Prevented migrating backwards from un…

…applying the wrong migrations."

Backport of d7ab2ce from master
  • Loading branch information...
timgraham committed Sep 24, 2014
1 parent 02aa3e3 commit d7b32d31205834262758ca5f48e5fe3a453f7ad3
@@ -36,15 +36,11 @@ def migration_plan(self, targets):
# If the migration is already applied, do backwards mode,
# otherwise do forwards mode.
elif target in applied:
- app_label = target[0]
- next_migration_prefix = str(int(target[1][:4]) + 1)
- try:
- next_migration = self.loader.get_migration_by_prefix(app_label, next_migration_prefix)
- except KeyError:
- # If `target` is the most recent one in its app, there is nothing to do.
- pass
- else:
- backwards_plan = self.loader.graph.backwards_plan(next_migration)
+ backwards_plan = self.loader.graph.backwards_plan(target)[:-1]
+ # We only do this if the migration is not the most recent one
+ # in its app - that is, another migration with the same app
+ # label is in the backwards plan
+ if any(node[0] == target[0] for node in backwards_plan):
for migration in backwards_plan:
if migration in applied:
plan.append((self.loader.graph.nodes[migration], True))
View
@@ -47,9 +47,6 @@ Bugfixes
* Allowed migrations to work with ``app_label``\s that have the same last
part (e.g. ``django.contrib.auth`` and ``vendor.auth``) (:ticket:`23483`).
-* Fixed bug in migrations that could cause unexpected data loss when executing
- a backwards or no-op migration (:ticket:`23474`).
-
* Restored the ability to deepcopy ``F`` objects (:ticket:`23492`).
* Formats for Welsh (``cy``) and several Chinese locales (``zh_CN``,
@@ -231,41 +231,3 @@ def test_custom_user(self):
executor.migrate([("migrations", None)])
self.assertTableNotExists("migrations_author")
self.assertTableNotExists("migrations_tribble")
-
- @override_settings(
- MIGRATION_MODULES={
- "migrations": "migrations.test_migrations_backwards_deps_1",
- "migrations2": "migrations2.test_migrations_backwards_deps_2",
- },
- )
- def test_backwards_deps(self):
- """
- #23474 - Migrating backwards shouldn't cause the wrong migrations to be
- unapplied.
-
- Migration dependencies (x -> y === y depends on x):
- m.0001 -+-> m.0002
- +-> m2.0001
-
- 1) Migrate m2 to 0001, causing { m.0001, m2.0002 } to be applied.
- 2) Migrate m to 0001. m.0001 has already been applied, so this should
- be a noop.
- """
- executor = MigrationExecutor(connection)
- executor.migrate([("migrations2", "0001_initial")])
- try:
- self.assertTableExists("migrations2_example")
- # Rebuild the graph to reflect the new DB state
- executor.loader.build_graph()
- self.assertEqual(
- executor.migration_plan([("migrations", "0001_initial")]),
- [],
- )
- executor.migrate([("migrations", "0001_initial")])
- self.assertTableExists("migrations2_example")
- finally:
- # And migrate back to clean up the database
- executor.loader.build_graph()
- executor.migrate([("migrations", None)])
- self.assertTableNotExists("migrations_author")
- self.assertTableNotExists("migrations_tribble")
@@ -1,16 +0,0 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
- dependencies = [('migrations', '0001_initial')]
- operations = [
- migrations.CreateModel(
- "Example",
- [
- ("id", models.AutoField(primary_key=True)),
- ],
- ),
- ]

0 comments on commit d7b32d3

Please sign in to comment.