[1.7.x] Fixed #24104 -- Fixed check to look on field.get_internal_type() instead of class instance (3d4a8261) · Commits · Dom Sekotill / django

django/db/backends/schema.py

+2 −3

Original line number	Diff line number	Diff line
		@@ -3,7 +3,6 @@ import operator

		from django.db.backends.creation import BaseDatabaseCreation
		from django.db.backends.utils import truncate_name
		from django.db.models.fields.related import ManyToManyField
		from django.db.transaction import atomic
		from django.utils.encoding import force_bytes
		from django.utils.log import getLogger
		@@ -359,7 +358,7 @@ class BaseDatabaseSchemaEditor(object):
		table instead (for M2M fields)
		"""
		# Special-case implicit M2M tables
		if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:
		if field.get_internal_type() == 'ManyToManyField' and field.rel.through._meta.auto_created:
		return self.create_model(field.rel.through)
		# Get the column's definition
		definition, params = self.column_sql(model, field, include_default=True)
		@@ -403,7 +402,7 @@ class BaseDatabaseSchemaEditor(object):
		but for M2Ms may involve deleting a table.
		"""
		# Special-case implicit M2M tables
		if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:
		if field.get_internal_type() == 'ManyToManyField' and field.rel.through._meta.auto_created:
		return self.delete_model(field.rel.through)
		# It might not actually have a column behind it
		if field.db_parameters(connection=self.connection)['type'] is None:

django/db/backends/sqlite3/schema.py

+4 −5

Original line number	Diff line number	Diff line
		@@ -4,7 +4,6 @@ from decimal import Decimal
		from django.utils import six
		from django.apps.registry import Apps
		from django.db.backends.schema import BaseDatabaseSchemaEditor
		from django.db.models.fields.related import ManyToManyField


		class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
		@@ -70,7 +69,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
		for field in create_fields:
		body[field.name] = field
		# Choose a default and insert it into the copy map
		if not isinstance(field, ManyToManyField):
		if not field.get_internal_type() == 'ManyToManyField':
		mapping[field.column] = self.quote_value(
		self.effective_default(field)
		)
		@@ -93,7 +92,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
		del body[field.name]
		del mapping[field.column]
		# Remove any implicit M2M tables
		if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:
		if field.get_internal_type() == 'ManyToManyField' and field.rel.through._meta.auto_created:
		return self.delete_model(field.rel.through)
		# Work inside a new app registry
		apps = Apps()
		@@ -172,7 +171,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
		table instead (for M2M fields)
		"""
		# Special-case implicit M2M tables
		if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:
		if field.get_internal_type() == 'ManyToManyField' and field.rel.through._meta.auto_created:
		return self.create_model(field.rel.through)
		self._remake_table(model, create_fields=[field])

		@@ -182,7 +181,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
		but for M2Ms may involve deleting a table.
		"""
		# M2M fields are a special case
		if isinstance(field, ManyToManyField):
		if field.get_internal_type() == 'ManyToManyField':
		# For implicit M2M tables, delete the auto-created table
		if field.rel.through._meta.auto_created:
		self.delete_model(field.rel.through)

docs/releases/1.7.4.txt

+4 −0

Original line number	Diff line number	Diff line
		@@ -20,3 +20,7 @@ Bugfixes

		* Prevented the ``static.serve`` view from producing ``ResourceWarning``\s in
		certain circumstances (security fix regression, :ticket:`24193`).

		* Fixed schema check for ``ManyToManyField`` to look for internal type instead
		of checking class instance, so you can write custom m2m-like fields with the
		same behavior. (:ticket:`24104`).

tests/schema/fields.py

0 → 100644

+54 −0

Original line number	Diff line number	Diff line
		from django.db.models.fields.related import (
		create_many_to_many_intermediary_model,
		ManyToManyField, ManyToManyRel, RelatedField,
		RECURSIVE_RELATIONSHIP_CONSTANT, ReverseManyRelatedObjectsDescriptor,
		)
		from django.utils.functional import curry


		class CustomManyToManyField(RelatedField):
		"""
		Ticket #24104 - Need to have a custom ManyToManyField,
		which is not an inheritor of ManyToManyField.
		"""

		def __init__(self, to, db_constraint=True, swappable=True, **kwargs):
		try:
		to._meta
		except AttributeError:
		to = str(to)
		kwargs['verbose_name'] = kwargs.get('verbose_name', None)
		kwargs['rel'] = ManyToManyRel(
		to,
		related_name=kwargs.pop('related_name', None),
		related_query_name=kwargs.pop('related_query_name', None),
		limit_choices_to=kwargs.pop('limit_choices_to', None),
		symmetrical=kwargs.pop('symmetrical', to == RECURSIVE_RELATIONSHIP_CONSTANT),
		through=kwargs.pop('through', None),
		through_fields=kwargs.pop('through_fields', None),
		db_constraint=db_constraint,
		)
		self.swappable = swappable
		self.db_table = kwargs.pop('db_table', None)
		if kwargs['rel'].through is not None:
		assert self.db_table is None, "Cannot specify a db_table if an intermediary model is used."
		super(CustomManyToManyField, self).__init__(**kwargs)

		def contribute_to_class(self, cls, name):
		if self.rel.symmetrical and (self.rel.to == "self" or self.rel.to == cls._meta.object_name):
		self.rel.related_name = "%s_rel_+" % name
		super(CustomManyToManyField, self).contribute_to_class(cls, name)
		if not self.rel.through and not cls._meta.abstract and not cls._meta.swapped:
		self.rel.through = create_many_to_many_intermediary_model(self, cls)
		setattr(cls, self.name, ReverseManyRelatedObjectsDescriptor(self))
		self.m2m_db_table = curry(self._get_m2m_db_table, cls._meta)

		def get_internal_type(self):
		return 'ManyToManyField'

		# Copy those methods from ManyToManyField because they don't call super() internally
		contribute_to_related_class = ManyToManyField.__dict__['contribute_to_related_class']
		set_attributes_from_rel = ManyToManyField.__dict__['set_attributes_from_rel']
		_get_m2m_attr = ManyToManyField.__dict__['_get_m2m_attr']
		_get_m2m_reverse_attr = ManyToManyField.__dict__['_get_m2m_reverse_attr']
		_get_m2m_db_table = ManyToManyField.__dict__['_get_m2m_db_table']

tests/schema/tests.py

+45 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@ from django.db.models.fields import (BinaryField, BooleanField, CharField, Integ
		PositiveIntegerField, SlugField, TextField)
		from django.db.models.fields.related import ForeignKey, ManyToManyField, OneToOneField
		from django.db.transaction import atomic
		from .fields import CustomManyToManyField
		from .models import (Author, AuthorWithDefaultHeight, AuthorWithM2M, Book, BookWithLongName,
		BookWithSlug, BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename,
		UniqueTest, Thing, TagThrough, BookWithM2MThrough, AuthorTag, AuthorWithM2MThrough,
		@@ -1310,3 +1311,47 @@ class SchemaTests(TransactionTestCase):
		cursor.execute("SELECT surname FROM schema_author;")
		item = cursor.fetchall()[0]
		self.assertEqual(item[0], None if connection.features.interprets_empty_strings_as_nulls else '')

		def test_custom_manytomanyfield(self):
		"""
		#24104 - Schema editors should look for internal type of field
		"""
		# Create the tables
		with connection.schema_editor() as editor:
		editor.create_model(AuthorWithM2M)
		editor.create_model(TagM2MTest)
		# Create an M2M field
		new_field = CustomManyToManyField("schema.TagM2MTest", related_name="authors")
		new_field.contribute_to_class(AuthorWithM2M, "tags")
		# Ensure there's no m2m table there
		self.assertRaises(DatabaseError, self.column_classes, new_field.rel.through)
		try:
		# Add the field
		with connection.schema_editor() as editor:
		editor.add_field(
		AuthorWithM2M,
		new_field,
		)
		# Ensure there is now an m2m table there
		columns = self.column_classes(new_field.rel.through)
		self.assertEqual(columns['tagm2mtest_id'][0], "IntegerField")

		# "Alter" the field. This should not rename the DB table to itself.
		with connection.schema_editor() as editor:
		editor.alter_field(
		AuthorWithM2M,
		new_field,
		new_field,
		)

		# Remove the M2M table again
		with connection.schema_editor() as editor:
		editor.remove_field(
		AuthorWithM2M,
		new_field,
		)
		# Ensure there's no m2m table there
		self.assertRaises(DatabaseError, self.column_classes, new_field.rel.through)
		finally:
		# Cleanup model states
		AuthorWithM2M._meta.local_many_to_many.remove(new_field)