Right-margin & aligning of "Composer"-field

[J . Van Thuyne]

The subjoined code results (both in versions 2.11.58 and 2.11.62) in a
Composer-field without a right margin. Is this a known issue, or am I missing a
mistake?


\version "2.11.62"

\paper {
  #(set-paper-size "a4")
  left-margin = 20
  right-margin = 20
  top-margin = 20
  between-system-space = 20
  systemSeparatorMarkup = \slashSeparator
}

\header {
  title = "Centered title"
  subsubtitle = "from \'Titles, from left to right\'"
  poet = "Poet"
  composer = "Composer, not OK."
}

melody = \relative c { a b c }

\score {
  \new Staff = "mel" \melody
}


--> http://hemiola.eu/rightmargin.pdf


Best regards,

Jethro.