gh-149738: Fix segmentation fault bug in sqllite3

Lib/test/test_sqlite3/test_factory.py

@@ -146,6 +146,14 @@ def test_sqlite_row_index(self):
         with self.assertRaises(IndexError):
             row[complex()]  # index must be int or string
 
+    def test_delete_connection_row_factory(self):
+        # gh-149738: deleting row_factory should not segfault
+        del self.con.row_factory
+        with self.assertRaises(sqlite.OperationalError):
+            self.con.execute("test")
+        cur = self.con.cursor()
+        self.assertIsNone(cur.row_factory)
+
     def test_sqlite_row_index_unicode(self):
         row = self.con.execute("select 1 as \xff").fetchone()
         self.assertEqual(row["\xff"], 1)

Misc/NEWS.d/next/Core_and_Builtins/2026-05-13-06-54-41.gh-issue-149738.4BLFoH.rst

@@ -0,0 +1,2 @@
+Fix a segmentation fault in :mod:`sqlite3` when ``row_factory`` is deleted
+and a query is executed afterward.

Modules/_sqlite/connection.c

@@ -549,7 +549,7 @@ pysqlite_connection_cursor_impl(pysqlite_Connection *self, PyObject *factory)
         return NULL;
     }
 
-    if (cursor && self->row_factory != Py_None) {
+    if (cursor && self->row_factory && self->row_factory != Py_None) {
         Py_INCREF(self->row_factory);
         Py_XSETREF(((pysqlite_Cursor *)cursor)->row_factory, self->row_factory);
     }