bug#56393: Actually fix the long lines display bug

[Gregory Heytings]

> > As I told you, I'll start working on the font locking slowdowns as soon 
> > as this branch is merged into master.  It shouldn't take more than a 
> > couple of weeks to fix them.
>
> Then I guess this is not very important either way.  (Still, leaving the 
> text until we know exactly what, if anything, to say instead sounds 
> better to me than removing it and then possibly adding some of it later. 
> But that's me.)

So... what do I do?