Commit 88786afb authored by Markus Holtermann's avatar Markus Holtermann
Browse files

Fixed #24147 -- Prevented managers leaking model during migrations 

Thanks Tim Graham for the review.
parent ec7ef5af

django/db/migrations/state.py

+15 −3
Original line number Diff line number Diff line
@@ -400,6 +400,19 @@ class ModelState(object): 
            field_class = import_string(path)

            yield name, field_class(*args, **kwargs)



    def construct_managers(self):

        "Deep-clone the managers using deconstruction"

        # Sort all managers by their creation counter

        sorted_managers = sorted(self.managers, key=lambda v: v[1].creation_counter)

        for mgr_name, manager in sorted_managers:

            as_manager, manager_path, qs_path, args, kwargs = manager.deconstruct()

            if as_manager:

                qs_class = import_string(qs_path)

                yield mgr_name, qs_class.as_manager()

            else:

                manager_class = import_string(manager_path)

                yield mgr_name, manager_class(*args, **kwargs)



    def clone(self):

        "Returns an exact copy of this ModelState"

        return self.__class__(
@@ -408,7 +421,7 @@ class ModelState(object): 
            fields=list(self.construct_fields()),

            options=dict(self.options),

            bases=self.bases,

            managers=self.managers,

            managers=list(self.construct_managers()),

        )



    def render(self, apps):
@@ -431,8 +444,7 @@ class ModelState(object): 
        body['__module__'] = "__fake__"



        # Restore managers

        for mgr_name, manager in self.managers:

            body[mgr_name] = manager

        body.update(self.construct_managers())



        # Then, make a Model object (apps.register_model is called in __new__)

        return type(

tests/migrations/test_state.py

+38 −0
Original line number Diff line number Diff line 
from django.apps.registry import Apps

from django.db import models

from django.db.migrations.operations import RemoveField

from django.db.migrations.state import ProjectState, ModelState, InvalidBasesError

from django.test import TestCase
@@ -505,6 +506,43 @@ class StateTests(TestCase): 
            ["id", "author"],

        )



    def test_manager_refer_correct_model_version(self):

        """

        #24147 - Tests that managers refer to the correct version of a

        historical model

        """

        project_state = ProjectState()

        project_state.add_model(ModelState(

            app_label="migrations",

            name="Tag",

            fields=[

                ("id", models.AutoField(primary_key=True)),

                ("hidden", models.BooleanField()),

            ],

            managers=[

                ('food_mgr', FoodManager('a', 'b')),

                ('food_qs', FoodQuerySet.as_manager()),

            ]

        ))



        old_model = project_state.apps.get_model('migrations', 'tag')



        new_state = project_state.clone()

        operation = RemoveField("tag", "hidden")

        operation.state_forwards("migrations", new_state)



        new_model = new_state.apps.get_model('migrations', 'tag')



        self.assertIsNot(old_model, new_model)

        self.assertIs(old_model, old_model.food_mgr.model)

        self.assertIs(old_model, old_model.food_qs.model)

        self.assertIs(new_model, new_model.food_mgr.model)

        self.assertIs(new_model, new_model.food_qs.model)

        self.assertIsNot(old_model.food_mgr, new_model.food_mgr)

        self.assertIsNot(old_model.food_qs, new_model.food_qs)

        self.assertIsNot(old_model.food_mgr.model, new_model.food_mgr.model)

        self.assertIsNot(old_model.food_qs.model, new_model.food_qs.model)





class ModelStateTests(TestCase):

    def test_custom_model_base(self):