Revert "Fixed #23474 -- Prevented migrating backwards from unapplying the wrong migrations." (d7ab2cef) · Commits · Dom Sekotill / django

django/db/migrations/executor.py

+5 −9

Original line number	Diff line number	Diff line
		@@ -36,15 +36,11 @@ class MigrationExecutor(object):
		# 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))

+0 −3

Original line number	Diff line number	Diff line
		@@ -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``,

+0 −38

Original line number	Diff line number	Diff line
		@@ -231,41 +231,3 @@ class ExecutorTests(MigrationTestBase):
		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")

deleted100644 → 0

+0 −0

Empty file deleted.

deleted100644 → 0

+0 −16

Original line number	Diff line number	Diff line
		# -- 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)),
		],
		),
		]