bug#11068: 24.0.94; Face-remapped background does not extend to end of window

[martin rudalics]

> Correct.  But only for lines that end before EOB.  The line that ends
> _at_ EOB and all the subsequent lines don't have this stretch glyph.
> The changes I did introduce such stretch glyphs for _all_ lines in the
> window than don't already have them.

So you do use an established mechanism but for the fact that these lines
exist only virtually.  Or am I missing something?

>> And it takes the face property not from the return character but
>> from the remapped default face.
>
> No, the return character has no face,

But when drawing the stretch glyph at a non-EOB line end the display
engine does use the face of the return character.  In my
`font-lock-fontify-syntactically-region' function I strip all face
properties from the return character and the rest of the line has the
default background.

> and in fact it has no glyphs.
> The original code would reset the face to the (un-remapped) default
> face when it hits the line at EOB, and would not draw past EOB at all,
> instead relying on the display-specific code that clears the rest of
> the window with the default color.

Couldn't we "clear" using the remapped default color as well?  Does
"clearing" care about character heights, for example?

>> As an aside I earlier tried to achieve the effect of your patch by
>> adding an overlay with an after-string containing an appropriate number
>> of return characters to the last character of each buffer.  It didn't
>> work and I still consider that a bug.
>
> If you show me the code, I will see if it's a bug or something else.

If you do, for example,

(let ((overlay (make-overlay (point-max) (point-max))))
  (overlay-put overlay 'after-string "\n\n\n\n"))

you can't move to the position before the overlay which makes the whole
thing worthless.

martin