[1.7.x] Fixed #24037 -- Prevented data loss possibility when changing Meta.managed.

The migrations autodetector now issues AlterModelOptions operations for
Meta.managed changes instead of DeleteModel + CreateModel.

Thanks iambibhas for the report and Simon and Markus for review.

Backport of 061caa5b38 from master
This commit is contained in:
Tim Graham 2014-12-23 12:27:49 -05:00
parent ac098867c0
commit 51ea30a43b
4 changed files with 43 additions and 17 deletions

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@ -454,8 +454,9 @@ class MigrationAutodetector(object):
We also defer any model options that refer to collections of fields
that might be deferred (e.g. unique_together, index_together).
"""
added_models = set(self.new_model_keys) - set(self.old_model_keys)
added_unmanaged_models = set(self.new_unmanaged_keys) - set(self.old_unmanaged_keys)
old_keys = set(self.old_model_keys).union(self.old_unmanaged_keys)
added_models = set(self.new_model_keys) - old_keys
added_unmanaged_models = set(self.new_unmanaged_keys) - old_keys
models = chain(
sorted(added_models, key=self.swappable_first_key, reverse=True),
sorted(added_unmanaged_models, key=self.swappable_first_key, reverse=True)
@ -630,19 +631,14 @@ class MigrationAutodetector(object):
We also bring forward removal of any model options that refer to
collections of fields - the inverse of generate_created_models().
"""
deleted_models = set(self.old_model_keys) - set(self.new_model_keys)
deleted_unmanaged_models = set(self.old_unmanaged_keys) - set(self.new_unmanaged_keys)
new_keys = set(self.new_model_keys).union(self.new_unmanaged_keys)
deleted_models = set(self.old_model_keys) - new_keys
deleted_unmanaged_models = set(self.old_unmanaged_keys) - new_keys
models = chain(sorted(deleted_models), sorted(deleted_unmanaged_models))
for app_label, model_name in models:
model_state = self.from_state.models[app_label, model_name]
model = self.old_apps.get_model(app_label, model_name)
if not model._meta.managed:
self.add_operation(
app_label,
operations.DeleteModel(
name=model_state.name,
),
)
# Skip here, no need to handle fields for unmanaged models
continue
@ -952,7 +948,18 @@ class MigrationAutodetector(object):
makes an operation to represent them in state changes (in case Python
code in migrations needs them)
"""
models_to_check = self.kept_model_keys.union(self.kept_proxy_keys).union(self.kept_unmanaged_keys)
models_to_check = self.kept_model_keys.union(
self.kept_proxy_keys
).union(
self.kept_unmanaged_keys
).union(
# unmanaged converted to managed
set(self.old_unmanaged_keys).intersection(self.new_model_keys)
).union(
# managed converted to unmanaged
set(self.old_model_keys).intersection(self.new_unmanaged_keys)
)
for app_label, model_name in sorted(models_to_check):
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]

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@ -356,6 +356,7 @@ class AlterModelOptions(Operation):
# Model options we want to compare and preserve in an AlterModelOptions op
ALTER_OPTION_KEYS = [
"get_latest_by",
"managed",
"ordering",
"permissions",
"default_permissions",

View File

@ -162,3 +162,8 @@ Bugfixes
* Added ``datetime.time`` support to migrations questioner (:ticket:`23998`).
* Fixed admindocs crash on apps installed as eggs (:ticket:`23525`).
* Changed migrations autodetector to generate an ``AlterModelOptions`` operation
instead of ``DeleteModel`` and ``CreateModel`` operations when changing
``Meta.managed``. This prevents data loss when changing ``managed`` from
``False`` to ``True`` and vice versa (:ticket:`24037`).

View File

@ -1021,7 +1021,7 @@ class AutodetectorTests(TestCase):
# The field name the FK on the book model points to
self.assertEqual(changes['otherapp'][0].operations[0].fields[2][1].rel.field_name, 'pk_field')
def test_unmanaged(self):
def test_unmanaged_create(self):
"""Tests that the autodetector correctly deals with managed models."""
# First, we test adding an unmanaged model
before = self.make_project_state([self.author_empty])
@ -1031,9 +1031,10 @@ class AutodetectorTests(TestCase):
# Right number/type of migrations?
self.assertNumberMigrations(changes, 'testapp', 1)
self.assertOperationTypes(changes, 'testapp', 0, ["CreateModel"])
self.assertOperationAttributes(changes, 'testapp', 0, 0, name="AuthorUnmanaged")
self.assertEqual(changes['testapp'][0].operations[0].options['managed'], False)
self.assertOperationAttributes(changes, 'testapp', 0, 0,
name="AuthorUnmanaged", options={"managed": False})
def test_unmanaged_to_managed(self):
# Now, we test turning an unmanaged model into a managed model
before = self.make_project_state([self.author_empty, self.author_unmanaged])
after = self.make_project_state([self.author_empty, self.author_unmanaged_managed])
@ -1041,9 +1042,21 @@ class AutodetectorTests(TestCase):
changes = autodetector._detect_changes()
# Right number/type of migrations?
self.assertNumberMigrations(changes, 'testapp', 1)
self.assertOperationTypes(changes, 'testapp', 0, ["DeleteModel", "CreateModel"])
self.assertOperationAttributes(changes, 'testapp', 0, 0, name="AuthorUnmanaged")
self.assertOperationAttributes(changes, 'testapp', 0, 1, name="AuthorUnmanaged")
self.assertOperationTypes(changes, 'testapp', 0, ["AlterModelOptions"])
self.assertOperationAttributes(changes, 'testapp', 0, 0,
name="authorunmanaged", options={})
def test_managed_to_unmanaged(self):
# Now, we turn managed to unmanaged.
before = self.make_project_state([self.author_empty, self.author_unmanaged_managed])
after = self.make_project_state([self.author_empty, self.author_unmanaged])
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number/type of migrations?
self.assertNumberMigrations(changes, 'testapp', 1)
self.assertOperationTypes(changes, "testapp", 0, ["AlterModelOptions"])
self.assertOperationAttributes(changes, "testapp", 0, 0,
name="authorunmanaged", options={"managed": False})
def test_unmanaged_custom_pk(self):
"""