bug in line-wrap mode

[koreno]

• at the top of the screen I have a long line.
• shift-w to turn on line-wrapping - the line now flows down beyond one screen.
• move down (down arrow) - the entire line is gone. I can't scroll towards the end of that line

(see REG-10615-V3MFS0-16236/testlight.log:42996)

[tigrawap]

"fixing" this is kinda an effort....with some corner cases.
So i went for vim-like behaviour here, when one line down is one line down.
It's actually more convenient when multiple long lines fit in the screen

Not saying that I don't want to allow such navigation, but it's tricky and more like feature with non-obvious behaviour to me, then bug...

[koreno]

you could make cursor right/left behave as 'intra-line movements', since these keys don't really have a function in line-wrapped mode anyway