Re: 23.0.60; Deja vu font breaks mouse-face highlighting in Gnus

[bojohan+news@dd.chalmers.se (Johan Bockgård)]

Stephen Berman <Stephen.Berman@gmx.net> writes:

> Other Dejavu fonts also show the gap in highlighting, but the range of
> susceptible strings seems to be less than with Dejavu Sans Mono.  I
> have tried using a number of other fonts but so far haven't found any
> others that show the display problem.

The problem happens for characters that stick out of their box.  It is
most noticeable with an italic font.

E.g. try

    (font-lock-mode 0)
    (insert (propertize "XXXXXX" 'face 'italic 'mouse-face 'highlight))


The responsible code is this part in `draw_glyphs':

   /* If there are any glyphs with lbearing < 0 or rbearing > width in
      the row, redraw some glyphs in front or following the glyph
      strings built above.  */
  if (head && !overlaps && row->contains_overlapping_glyphs_p)
     {
       ...

-- 
Johan Bockgård