bpo-42972: Track sqlite3 statement objects

Author: Erlend E. Aasland

Modules/_sqlite/connection.c

@@ -1363,6 +1363,7 @@ pysqlite_connection_call(pysqlite_Connection *self, PyObject *args,
     statement->in_weakreflist = NULL;
 
     rc = pysqlite_statement_create(statement, self, sql);
+    PyObject_GC_Track(statement);
     if (rc != SQLITE_OK) {
         if (rc == PYSQLITE_TOO_MUCH_SQL) {
             PyErr_SetString(pysqlite_Warning, "You can only execute one statement at a time.");

Modules/_sqlite/cursor.c

@@ -512,6 +512,7 @@ _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* operation
             goto error;
         }
         rc = pysqlite_statement_create(self->statement, self->connection, operation);
+        PyObject_GC_Track(self->statement);
         if (rc != SQLITE_OK) {
             Py_CLEAR(self->statement);
             goto error;