I think i have an idea how to explain this bug.
I suppose it happens because LilyPond is not aware that the dot
is in
voiceTwo context (and therefore lower than usual).
compile this:
{ g'4.*1/32 d''!32 g'4.*1/32 e''!32 }
{ \voiceTwo g'4.*1/32 \voiceOne d''!32 \voiceTwo g'4.*1/32
\voiceOne e''!32
}
In the upper line, the first accidental (on d'') is too low to
move
left (it would collide with the dot). The second accidental (on
e'')
is high enough to be moved over dot. Everything fine here.
Now in the second line the music is the same except that dotted
notes
are in lower voice. This makes the dots move down, they are a
whole
staffspace lower. However, Lily fails to notice that, and
engraves the
naturals exactly like in the upper line.