Re: 23.0.50; Display bug with vline.el and viper

[Vinicius Jose Latorre]

> Hm, you placed (redisplay t) inside the (save-excursion ...) form. 
> That cures the bug I reported, but it gives other very strange bugs. 
> Maximize the window and then press up and down arrows. Instead of just 
> moving the point at least up arrow much of the time scrolls the window.

Indeed, just typing C-n, after half window height, next C-n causes a 
scroll up, next C-n causes a scroll down, next C-n scroll up, and so on.

Despite this weird behavior, the point advances one line at time as it 
should.