Properly reset the transaction flag

Author: Cito

dbutils/steady_db.py

@@ -758,7 +758,7 @@ def tough_method(*args, **kwargs):
                     with suppress(Exception):
                         con2.close()
                 if transaction:
-                    self._transaction = False
+                    con._transaction = False
                 raise error  # re-raise the original error again
             else:
                 con._usage += 1

docs/changelog.html

@@ -28,6 +28,12 @@ <h2>3.2.0</h2>
 <li><p>Added <span class="docutils literal">dbapi_connection</span> and <span class="docutils literal">dbapi_cursor</span> attributes providing
 supported access to the underlying DB-API 2 objects.</p></li>
 </ul>
+<p>Bugfixes:</p>
+<ul class="simple">
+<li><p>Fixed the transaction flag being reset on the cursor instead of the
+connection when a connection could not be reopened during a transaction,
+which kept the failover mechanism suspended.</p></li>
+</ul>
 </section>
 <section id="section-2">
 <h2>3.1.2</h2>

docs/changelog.rst

@@ -20,6 +20,12 @@ Changes:
 * Added ``dbapi_connection`` and ``dbapi_cursor`` attributes providing
   supported access to the underlying DB-API 2 objects.
 
+Bugfixes:
+
+* Fixed the transaction flag being reset on the cursor instead of the
+  connection when a connection could not be reopened during a transaction,
+  which kept the failover mechanism suspended.
+
 3.1.2
 =====
 

tests/test_steady_db.py

@@ -730,6 +730,29 @@ def test_rollback_error():
     assert db._con.valid
 
 
+def test_transaction_ended_when_reopening_fails():
+    """A transaction that cannot be reopened must not stay active.
+
+    Otherwise the failover mechanism would stay suspended on the
+    connection, so that it could never recover by itself again.
+    """
+    db = steady_db_connect(dbapi, database='ok')
+    cursor = db.cursor()
+    db.begin()
+    assert db._transaction
+    # the database goes away and cannot be reached again
+    db._kwargs['database'] = 'error'
+    db._con.valid = cursor._cursor.valid = False
+    with pytest.raises(dbapi.InternalError):
+        cursor.execute('select test')
+    assert not db._transaction
+    # when the database is back, the failover mechanism must work again
+    db._kwargs['database'] = 'ok'
+    cursor.execute('select test')
+    assert cursor.fetchone() == 'test'
+    assert db._con.valid
+
+
 def timeout_is_not_fatal(error):
     """A deliberate server side timeout does not break the connection."""
     return not error.args or error.args[0] != 3024