bug#19395: 25.0.50; Setting left fringe to 0 messes up window-width

[Stefan Monnier]

> As long as the left fringe exists, we can display on it.  But once its
> width is zero, it no longer exists, and so we need to reserve space to
> display the continuation glyph "by other means".

That sounds wrong: if the user decides to get rid of the left-fringe,
she just shouldn't get any continuation glyph on the left.


        Stefan