Multi-column character on the right edge and highlighting

Multi-column character on the right edge and highlighting

[Kyotaro HORIGUCHI]

In the frame with 80 column width, a two-column width character
at 80th column is pushed out into the next line and the last
column of the first line becomes void.

When this continued lines are highlighed together and then
restored, the void column remains highlighed. This can be caused
by using transient-mark-mode.


This behavior is caused by set_glyph_string_background_width() in
xdisp.c.

| set_glyph_string_background_width (s, start, last_x)
| ...
|   if (start == s->row->used[s->area]
|       && s->area == TEXT_AREA
|       && ((s->hl == DRAW_NORMAL_TEXT
| 	   && (s->row->fill_line_p
==> 	       || s->face->background != default_face->background
| 	       || s->face->stipple != default_face->stipple
| 	       || s->row->mouse_face_p))
| 	  || s->hl == DRAW_MOUSE_FACE
| 	  || ((s->hl == DRAW_IMAGE_RAISED || s->hl == DRAW_IMAGE_SUNKEN)
| 	      && s->row->fill_line_p)))
|       s->extends_to_end_of_line_p = 1;

The condition marked with `==>' inhibits restoring highlighted
void column. Removing this condition settles the problem.

I can't understand why this condition is there, so I have no idea
of whether this condition may be simply removed or not.

-- 
Kyotaro HORIGUCHI

Re: Multi-column character on the right edge and highlighting

[Kim F. Storm]

Kyotaro HORIGUCHI <horiguti@meadowy.org> writes:

> In the frame with 80 column width, a two-column width character
> at 80th column is pushed out into the next line and the last
> column of the first line becomes void.
>
> When this continued lines are highlighed together and then
> restored, the void column remains highlighed. This can be caused
> by using transient-mark-mode.
>
>
> This behavior is caused by set_glyph_string_background_width() in
> xdisp.c.
>
> | set_glyph_string_background_width (s, start, last_x)
> | ...
> |   if (start == s->row->used[s->area]
> |       && s->area == TEXT_AREA
> |       && ((s->hl == DRAW_NORMAL_TEXT
> | 	   && (s->row->fill_line_p
> ==> 	       || s->face->background != default_face->background
> | 	       || s->face->stipple != default_face->stipple
> | 	       || s->row->mouse_face_p))
> | 	  || s->hl == DRAW_MOUSE_FACE
> | 	  || ((s->hl == DRAW_IMAGE_RAISED || s->hl == DRAW_IMAGE_SUNKEN)
> | 	      && s->row->fill_line_p)))
> |       s->extends_to_end_of_line_p = 1;
>
> The condition marked with `==>' inhibits restoring highlighted
> void column. Removing this condition settles the problem.
>
> I can't understand why this condition is there, so I have no idea
> of whether this condition may be simply removed or not.

I don't quite understand why that condition is a problem -- 

Based on your description of the problem, it seems correct to extend
the background to the end of the line, so why does it fix the bug to
_remove_ a condition for extending the face to EOL?!


-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: Multi-column character on the right edge and highlighting

[Kim F. Storm]

Kyotaro HORIGUCHI <horiguti@meadowy.org> writes:

> In the frame with 80 column width, a two-column width character
> at 80th column is pushed out into the next line and the last
> column of the first line becomes void.
>
> When this continued lines are highlighed together and then
> restored, the void column remains highlighed. This can be caused
> by using transient-mark-mode.

I have installed a fix for this.  Please check if it fixes the problem.

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: Multi-column character on the right edge and highlighting

[Kyotaro HORIGUCHI]

> > When this continued lines are highlighed together and then
> > restored, the void column remains highlighed. This can be caused
> > by using transient-mark-mode.
> 
> I have installed a fix for this.  Please check if it fixes the problem.

 The problem has been fixed. Thank you.

-- 
Kyotaro HORIGUCHI