gh-129346: Assert SQLite aggregate context cannot be NULL in the step handler

Author: erlend-aasland

Modules/_sqlite/connection.c

@@ -958,6 +958,7 @@ step_callback(sqlite3_context *context, int argc, sqlite3_value **params)
     assert(ctx != NULL);
 
     aggregate_instance = (PyObject**)sqlite3_aggregate_context(context, sizeof(PyObject*));
+    assert(aggregate_instance != NULL);
     if (*aggregate_instance == NULL) {
         *aggregate_instance = PyObject_CallNoArgs(ctx->callable);
         if (!*aggregate_instance) {