bug#23574: 24.5; Overzealous underlining in emacs-nox

[martin rudalics]

>> Which gets me back to my initial concern: If our user does that eagerly
>> for the entire buffer, the overhead might be non-negligible.
>
> I don't see why.  Redisplay only considers the visible portion of the
> buffer.

I meant the overhead for adding the text property to every newline
character in the buffer.

> row->pixel_width doesn't count text glyphs, it counts all of the
> glyphs in a glyph row, including the glyphs produced by the display
> engine for its own purposes.  E.g., it always includes the space glyph
> produced at the end of a line, which is needed for displaying the
> cursor.

Are there any other significant objects but that space glyph?  Is there
any other way to get the size of the empty space after text on each row?

> row->pixel_width is computed in compute_line_metrics,
> after the stretch glyph (and any other glyphs needed for line display)
> were already inserted.  compute_line_metrics doesn't care about what
> glyphs are there, it counts them all.

Hmm... How would I get the width of that stretch glyph then?

martin