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

[Vinicius Jose Latorre <viniciusjl@ig.com.br>]

>>     Try to insert:
>>
>>     (redisplay t)
>>
>>     At the end of vline-show function.
>>
>> If this is something magic, perhaps we need to document in the Lisp
>> manual the need for this.  Can someone propose a patch to the manual?
>
> Maybe it is magic, but then the magic is not strong enough for this 
> display bug. But maybe something like that function should be called 
> internally for certain cases? Here it seems like wrapped lines are 
> involved.

I've just tested vline.el with the fix above, and it works.

Probably Lennart inserted (redisplay t) inside the last while.

The problem is the following:

1. there are long lines (lines which go beyond window width) and one 
long line is at end of window (one part of the line is in the current 
window and the rest of line is in the next window);

2. when a scroll occurs (via next-line, for example), the vline-show is 
called during window scroll process;

3. vline-show changes the display while the display is being changed by 
window scroll, this gives some kind of conflict that (redisplay t) seems 
to fix.

Maybe the explanation is not so precise, but I hope it helps.