Commit 728548e4 authored by Aymeric Augustin's avatar Aymeric Augustin
Browse files

Fixed #21134 -- Prevented queries in broken transactions. 

Squashed commit of the following:

commit 63ddb271a44df389b2c302e421fc17b7f0529755
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Sun Sep 29 22:51:00 2013 +0200

    Clarified interactions between atomic and exceptions.

commit 2899ec299228217c876ba3aa4024e523a41c8504
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Sun Sep 22 22:45:32 2013 +0200

    Fixed TransactionManagementError in tests.

    Previous commit introduced an additional check to prevent running
    queries in transactions that will be rolled back, which triggered a few
    failures in the tests. In practice using transaction.atomic instead of
    the low-level savepoint APIs was enough to fix the problems.

commit 4a639b059ea80aeb78f7f160a7d4b9f609b9c238
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Tue Sep 24 22:24:17 2013 +0200

    Allowed nesting constraint_checks_disabled inside atomic.

    Since MySQL handles transactions loosely, this isn't a problem.

commit 2a4ab1cb6e83391ff7e25d08479e230ca564bfef
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Sat Sep 21 18:43:12 2013 +0200

    Prevented running queries in transactions that will be rolled back.

    This avoids a counter-intuitive behavior in an edge case on databases
    with non-atomic transaction semantics.

    It prevents using savepoint_rollback() inside an atomic block without
    calling set_rollback(False) first, which is backwards-incompatible in
    tests.

    Refs #21134.

commit 8e3db393853c7ac64a445b66e57f3620a3fde7b0
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date:   Sun Sep 22 22:14:17 2013 +0200

    Replaced manual savepoints by atomic blocks.

    This ensures the rollback flag is handled consistently in internal APIs.
parent 9595183d

django/contrib/sessions/backends/db.py

+2 −3
Original line number Diff line number Diff line
@@ -58,12 +58,11 @@ class SessionStore(SessionBase): 
            expire_date=self.get_expiry_date()

        )

        using = router.db_for_write(Session, instance=obj)

        sid = transaction.savepoint(using=using)

        try:

            with transaction.atomic(using=using):

                obj.save(force_insert=must_create, using=using)

        except IntegrityError:

            if must_create:

                transaction.savepoint_rollback(sid, using=using)

                raise CreateError

            raise

django/db/backends/__init__.py

+9 −0
Original line number Diff line number Diff line
@@ -361,6 +361,12 @@ class BaseDatabaseWrapper(object): 
            raise TransactionManagementError(

                "This is forbidden when an 'atomic' block is active.")



    def validate_no_broken_transaction(self):

        if self.needs_rollback:

            raise TransactionManagementError(

                "An error occurred in the current transaction. You can't "

                "execute queries until the end of the 'atomic' block.")



    def abort(self):

        """

        Roll back any ongoing transaction and clean the transaction state
@@ -638,6 +644,9 @@ class BaseDatabaseFeatures(object): 
    # when autocommit is disabled? http://bugs.python.org/issue8145#msg109965

    autocommits_when_autocommit_is_off = False



    # Does the backend prevent running SQL queries in broken transactions?

    atomic_transactions = True



    # Can we roll back DDL in a transaction?

    can_rollback_ddl = False

django/db/backends/mysql/base.py

+8 −1
Original line number Diff line number Diff line
@@ -172,6 +172,7 @@ class DatabaseFeatures(BaseDatabaseFeatures): 
    requires_explicit_null_ordering_when_grouping = True

    allows_primary_key_0 = False

    uses_savepoints = True

    atomic_transactions = False

    supports_check_constraints = False



    def __init__(self, connection):
@@ -484,7 +485,13 @@ class DatabaseWrapper(BaseDatabaseWrapper): 
        """

        Re-enable foreign key checks after they have been disabled.

        """

        # Override needs_rollback in case constraint_checks_disabled is

        # nested inside transaction.atomic.

        self.needs_rollback, needs_rollback = False, self.needs_rollback

        try:

            self.cursor().execute('SET foreign_key_checks=1')

        finally:

            self.needs_rollback = needs_rollback



    def check_constraints(self, table_names=None):

        """

django/db/backends/oracle/base.py

+1 −0
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ class DatabaseFeatures(BaseDatabaseFeatures): 
    has_bulk_insert = True

    supports_tablespaces = True

    supports_sequence_reset = False

    atomic_transactions = False

    supports_combined_alters = False

    max_index_name_length = 30

    nulls_order_largest = True

django/db/backends/sqlite3/base.py

+1 −0
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ class DatabaseFeatures(BaseDatabaseFeatures): 
    supports_foreign_keys = False

    supports_check_constraints = False

    autocommits_when_autocommit_is_off = True

    atomic_transactions = False

    supports_paramstyle_pyformat = False

    supports_sequence_reset = False