Augmentation dots for two voices, same note

[Marcus Macauley]

Hi,

When dotted notes with overlapping noteheads occur in multiple voices,
and the notehead lies on a staff line, only one dot appears, instead of
two (one above and one below the staff line), which there should be.

Using dotsUp and dotsDown on the respective voices affects the placement
of the single dot (according to the dot setting of the lower voice -
dotsUp dotsDown [default for the lower voice], or dotsNeutral), but no
combination of dotsUp/Down/Neutral settings will separate the dots so
that two dots, instead of one, are visible.

Following is an example, which I tested in version 2.5.0, though I
expect the behavior is common to all versions, or at least all recent
versions.

If anyone knows of a workaround, please let me know.

Thanks,
Marcus Macauley

%---start dotsbug.ly---
\header { texidoc = "
The first and third Gs should have augmentation dots above and below the
staff line, one for each voice.
" }

\include "english.ly"

\layout {
  indent = 0\mm
  raggedright = ##t
  
  \context {
    \Staff
    \remove "Time_signature_engraver"
  }
  
}

\relative c'' {
  <<
    {
      g2.^"no setting" a4 | g2. a4 | g4. a8 bf8. a16 r4 \break

      \dotsNeutral
      g2.^"dotsNeutral" a4 | g2. a4 | g4. a8 bf8. a16 r4 \break
      
      \dotsUp
      g2.^"dotsUp" a4 | g2. a4 | g4. a8 bf8. a16 r4 \break
      
      \dotsUp
      g2.^"dotsUp" a4 | g2. a4 | g4. a8 bf8. a16 r4 \break
      
      \dotsDown
      g2.^"dotsDown" a4 | g2. a4 | g4. a8 bf8. a16 r4 \break
      
    }
    \\
    {
      g2._"no setting" f4 | g4. f8 e4 f | g8. f16 e8 f e8. f16 r4 \break

      \dotsNeutral
      g2._"dotsNeutral" f4 | g4. f8 e4 f | g8. f16 e8 f e8. f16 r4
\break
      
      \dotsUp
      g2._"dotsUp" f4 | g4. f8 e4 f | g8. f16 e8 f e8. f16 r4 \break
      
      \dotsDown
      g2._"dotsDown" f4 | g4. f8 e4 f | g8. f16 e8 f e8. f16 r4 \break

      \dotsUp
      g2._"dotsUp" f4 | g4. f8 e4 f | g8. f16 e8 f e8. f16 r4 \break
      
    }
  >>
}
%---end dotsbug.ly---