strange "piano centered dynamics" behavior

[Mark Polesky]

Does anyone know what's going on here?  Adding a marcato to
the note "c" shifts the dynamic up so that it's no longer
centered.

- Mark


\version "2.13.18"

upperA = \relative g' {
  g8 a b c c,2
}

upperB = \relative g' {
  g8 a b c c,2-^
}

lower = \relative c {
  \clef bass c2 <g c e>2
}

dynamics = {
  s1\p
}

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

\score {
  \new PianoStaff <<
    \new Staff \upperA
    \new Dynamics \dynamics
    \new Staff \lower
  >>
}

\score {
  \new PianoStaff <<
    \new Staff \upperB
    \new Dynamics \dynamics
    \new Staff \lower
  >>
}

centered-dynamics.png
Description: PNG image