CJK characters in rio seem to displays "higher" than Latins. It's a good idea, because CJK characters become more readable with more vertical spaces. (In contrast, that in vim is less readable)

However, I found that after a long CJK text was output in rio terminal, it run into a strange status...

If all characters are Latin, everything works well like the top-left terminal shows.

But when characters are all CJK or CJK/Latin mixed, as the right terminal shows, the terminal scrolls less than 4 lines down after the printf command executed.

I think the problem is caused by rio assuming the height of contents is equal to that of 4 Latin character lines, not 4 CJK/Latin mixed character lines.

Here are two examples with two passages, one is Li Sao in Chinese, the other is a part of Hamlet. After cat Hamlet everything goes well, but after cat "Li Sao" it scrolls to quite a wrong place and I cannot even see the input line!