Fixed #23452 -- Prevented infinite migrations for empty unique/index_together. (6d5958c7) · Commits · Dom Sekotill / django

django/db/migrations/autodetector.py

+11 −6

Original line number	Diff line number	Diff line
		@@ -871,23 +871,28 @@ class MigrationAutodetector(object):
		old_model_name = self.renamed_models.get((app_label, model_name), model_name)
		old_model_state = self.from_state.models[app_label, old_model_name]
		new_model_state = self.to_state.models[app_label, model_name]

		# We run the old version through the field renames to account for those
		if old_model_state.options.get(option_name) is None:
		old_value = None
		else:
		old_value = old_model_state.options.get(option_name) or set()
		if old_value:
		old_value = set([
		tuple(
		self.renamed_fields.get((app_label, model_name, n), n)
		for n in unique
		)
		for unique in old_model_state.options[option_name]
		for unique in old_value
		])
		if old_value != new_model_state.options.get(option_name):

		new_value = new_model_state.options.get(option_name) or set()
		if new_value:
		new_value = set(new_value)

		if old_value != new_value:
		self.add_operation(
		app_label,
		operation(
		name=model_name,
		**{option_name: new_model_state.options.get(option_name)}
		**{option_name: new_value}
		)
		)

django/db/migrations/operations/models.py

+2 −6

Original line number	Diff line number	Diff line
		@@ -233,9 +233,7 @@ class AlterUniqueTogether(Operation):
		def __init__(self, name, unique_together):
		self.name = name
		unique_together = normalize_together(unique_together)
		# need None rather than an empty set to prevent infinite migrations
		# after removing unique_together from a model
		self.unique_together = set(tuple(cons) for cons in unique_together) or None
		self.unique_together = set(tuple(cons) for cons in unique_together)

		def state_forwards(self, app_label, state):
		model_state = state.models[app_label, self.name.lower()]
		@@ -273,9 +271,7 @@ class AlterIndexTogether(Operation):
		def __init__(self, name, index_together):
		self.name = name
		index_together = normalize_together(index_together)
		# need None rather than an empty set to prevent infinite migrations
		# after removing unique_together from a model
		self.index_together = set(tuple(cons) for cons in index_together) or None
		self.index_together = set(tuple(cons) for cons in index_together)

		def state_forwards(self, app_label, state):
		model_state = state.models[app_label, self.name.lower()]

docs/releases/1.7.1.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -31,3 +31,6 @@ Bugfixes
		``'auth.User'`` model (:ticket:`11775`). As a side effect, the setting now
		adds a ``get_absolute_url()`` method to any model that appears in
		``ABSOLUTE_URL_OVERRIDES`` but doesn't define ``get_absolute_url()``.

		* Empty ``index_together`` or ``unique_together`` model options no longer
		results in infinite migrations (:ticket:`23452`).

tests/migrations/test_autodetector.py

+46 −2

Original line number	Diff line number	Diff line
		@@ -529,6 +529,50 @@ class AutodetectorTests(TestCase):
		# Right number of migrations?
		self.assertEqual(len(changes), 0)

		def test_empty_foo_together(self):
		"#23452 - Empty unique/index_togther shouldn't generate a migration."
		# Explicitly testing for not specified, since this is the case after
		# a CreateModel operation w/o any definition on the original model
		model_state_not_secified = ModelState("a", "model",
		[("id", models.AutoField(primary_key=True))]
		)
		# Explicitly testing for None, since this was the issue in #23452 after
		# a AlterFooTogether operation with e.g. () as value
		model_state_none = ModelState("a", "model",
		[("id", models.AutoField(primary_key=True))],
		{"unique_together": None, "index_together": None}
		)
		# Explicitly testing for the empty set, since we now always have sets.
		# During removal (('col1', 'col2'),) --> () this becomes set([])
		model_state_empty = ModelState("a", "model",
		[("id", models.AutoField(primary_key=True))],
		{"unique_together": set(), "index_together": set()}
		)

		def test(from_state, to_state, msg):
		before = self.make_project_state([from_state])
		after = self.make_project_state([to_state])
		autodetector = MigrationAutodetector(before, after)
		changes = autodetector._detect_changes()
		if len(changes) > 0:
		ops = ', '.join(o.__class__.__name__ for o in changes['a'][0].operations)
		self.fail('Created operation(s) %s from %s' % (ops, msg))

		tests = (
		(model_state_not_secified, model_state_not_secified, '"not specified" to "not specified"'),
		(model_state_not_secified, model_state_none, '"not specified" to "None"'),
		(model_state_not_secified, model_state_empty, '"not specified" to "empty"'),
		(model_state_none, model_state_not_secified, '"None" to "not specified"'),
		(model_state_none, model_state_none, '"None" to "None"'),
		(model_state_none, model_state_empty, '"None" to "empty"'),
		(model_state_empty, model_state_not_secified, '"empty" to "not specified"'),
		(model_state_empty, model_state_none, '"empty" to "None"'),
		(model_state_empty, model_state_empty, '"empty" to "empty"'),
		)

		for t in tests:
		test(*t)

		def test_unique_together_ordering(self):
		"Tests that unique_together also triggers on ordering changes"
		# Make state
		@@ -582,7 +626,7 @@ class AutodetectorTests(TestCase):
		# Right actions?
		action = migration.operations[0]
		self.assertEqual(action.__class__.__name__, "AlterIndexTogether")
		self.assertEqual(action.index_together, None)
		self.assertEqual(action.index_together, set())

		def test_remove_unique_together(self):
		author_unique_together = ModelState("testapp", "Author", [
		@@ -601,7 +645,7 @@ class AutodetectorTests(TestCase):
		# Right actions?
		action = migration.operations[0]
		self.assertEqual(action.__class__.__name__, "AlterUniqueTogether")
		self.assertEqual(action.unique_together, None)
		self.assertEqual(action.unique_together, set())

		def test_proxy(self):
		"Tests that the autodetector correctly deals with proxy models"