message: Clarify length of return buffer for appended leaves
diff: @@ -1230,7 +1230,7 @@ pub extern "system" fn librustzcash_mmr_append(
  nn_ptr: *const [u8; zcash_mmr::MAX_NODE_DATA_SIZE],
  // Return of root commitment
  rt_ret: *mut [u8; 32],
  - // Return buffer for appended leaves, should be pre-allocated of log2(t_len)+1 length
  + // Return buffer for appended leaves, should be pre-allocated of ceiling(log2(t_len)) length
  buf_ret: *mut [c_uchar; zcash_mmr::MAX_NODE_DATA_SIZE],
  ) -> u32 {
  let new_node_bytes: &[u8; zcash_mmr::MAX_NODE_DATA_SIZE] = unsafe {
  