C api bug (strings not null-terminated)

[starlitxiling]

When I use the C API, I find that some unpredictable id appear in read_dora_input_id, and it will be the same string I create after that. If I don't create it after that, it will be a segment of id plus a strange hexadecimal number (like BCAG). I think there is a pointer error phenomenon. I don't know if this is related to #540