Add a missing incref to c_headers_to_py (confluentinc#1165)

mitsuhiko · web-flow · commit 6b7f9a6a8be3 · 2021-07-28T15:10:37.000-05:00
Before the `c_headers_to_py` function had a branch where a refcount was
not correctly incremented.  This can cause the `Py_None` object to
eventually deallocate which will crash the interpreter.
diff --git a/src/confluent_kafka/src/confluent_kafka.c b/src/confluent_kafka/src/confluent_kafka.c
@@ -1299,6 +1299,7 @@ PyObject *c_headers_to_py (rd_kafka_headers_t *headers) {
                         cfl_PyBin(_FromStringAndSize(header_value, header_value_size))
                     );
             } else {
+                Py_INCREF(Py_None);
                 PyTuple_SetItem(header_tuple, 1, Py_None);
             }
         PyList_SET_ITEM(header_list, idx-1, header_tuple);

Original file line number	Diff line number	Diff line change
`@@ -1299,6 +1299,7 @@ PyObject c_headers_to_py (rd_kafka_headers_t headers) {`
`1299`	`1299`	`cfl_PyBin(_FromStringAndSize(header_value, header_value_size))`
`1300`	`1300`	`);`
`1301`	`1301`	`} else {`
	`1302`	`+ Py_INCREF(Py_None);`
`1302`	`1303`	`PyTuple_SetItem(header_tuple, 1, Py_None);`
`1303`	`1304`	`}`
`1304`	`1305`	`PyList_SET_ITEM(header_list, idx-1, header_tuple);`