EVM-C: output_data MAY be NULL
@@ -192,10 +192,14 @@ struct evm_result {
/// The memory containing the output data is owned by EVM and has to be
/// freed with evm_result::release().
///
+ /// This MAY be NULL.
+ ///
/// @todo Inconsistent name: output_data vs msg.input.
uint8_t const* output_data;
/// The size of the output data.
+ ///
+ /// If output_data is NULL this MUST be 0.
size_t output_size;
/// The pointer to a function releasing all resources associated with
