mcview scrolling issues with heavy utf-8 files

[egmont]

wget ​http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-demo.txt
mcview UTF-8-demo.txt

Scroll up and down with the arrow (or pgup/pgdn) keys. Notice that very often a partial line appears on the top row, you have to press the arrow key twice or even more times to actually scroll by one line.

This happens when the topmost line that you're scrolling in or out contains lots of non-ascii characters. More precisely, I believe this occurs exactly when the number of bytes forming the topmost row is bigger than the terminal's width.

Buggy both in 4.7.3 and 4.7.0.7, fully UTF-8 environment.

[egmont]

Screenshot - though experiencing the behavior is much more useful