improper alignment of 2 accidentals in the presence of a 2nd (interval)

[Mark Polesky]

Improper alignment of two accidentals in the presence 
of a 2nd (interval):

Two accidentals my improperly align in the presence
of an interval of a second, even if the accidentals
are in different voices, and even if the second is
split into different voices. Most examples I've 
found occur when the accidentals are an octave
apart, but I've included four situations (the last
line) where the accidentals are not an octave apart.
  
I've intentionally included non-problematic cases
to help isolate the cause. 

____________________________________________________

\version "2.11.63-1"

x = \markup \center-align \with-color #red "x"

\layout {
  indent = #0
  ragged-right = ##t
}

\relative {
  
  \override Score.TextScript #'staff-padding = #2.5
  
  <fis g gis'!>4 <fis g gis'!> <f g gis'!> <f g gis'!>
  <f gis gis'!>_\x <f gis gis'!> <f g! gis'!>_\x <f g gis'!>
  <gis a gis'!>_\x <gis a gis'!> <g a gis'!>_\x <g a gis'!>
  <g ais gis'!> <g ais gis'!> <g a gis'!> <g a gis'!>
  
  \break
  
  << {
    \repeat unfold 16 gis'!
  } \\ {
    <fis, g> <fis g> <f g> <f g>
    <f gis>_\x <f gis> <f g!>_\x <f g>
    <gis a>_\x <gis a> <g a>_\x <g a>
    <g ais> <g ais> <g a> <g a>
  } >>
  
  \break
  
  << {
    <gis gis'!> <gis gis'!> <g gis'!> <g gis'!>
    <ais gis'!> <ais gis'!> <a gis'!> <a gis'!>
    gis' gis! gis! gis!
  } \\ {
    <c,, d>_\x <c d> <c d>_\x <c d>
    <c d> <c d> <c d> <c d>
    <gis' f'>_\x <gis f'> <g f'>_\x <g f'>
  } >>
  
  \break
  
  <fis d' es>_\x << { es'! } \\ { <fis,! d'>_\x } >> 
  << { es'! } \\ { <gis, d'>_\x } >> 
  << { es' } \\ { <fis,! des'>_\x } >>
}

accidental-alignment.png
Description: PNG image