Bug report: measure numbering after repeat with alternative endings

[Paul de Bruin]

> I'm not top posting.

%% BUG in Measure Numbering:
%% after a \repeat ending in two \alternative measures, these two measures 
should bear the same number;
%% however, Lilypond gives them subsequent numbers; the next section of the 
piece starts with a measure
%% number one too high.
%% Example, see line 50.

\version "2.10.10"

\paper{ ragged-right=##t }

%  JSB Sonata BWV1017
%  Sonata Cembalo+Violino
%  1 Siciliano

\header {
title = "SONATA IV"
subtitle = "BWV 1017"
composer = "Johann Sebastian Bach (1685-1750)"
}

#(set-global-staff-size 19)

SicilianoS = \relative c' { 
  \key c \minor
  \time 6/8
  \clef treble

  \repeat volta 2 {  
  \stemUp
c16( es g c g es)   c( es g c g es)
c( f as c as f)     c( e g bes as g)
  \stemDown
as( bes c f c as)   f( as c f c as)
f b d f d b         f as c f c as
g b d f d c         b d f as c, b
c es g c g es       c es g c g es
c f as c as f       d f g bes g es
c es f as g f       c es f as g f
bes, c d f es d     as' g f es d c
bes d f bes f d     es ges a c bes a
es f ges bes d, c   d f d bes f as

g bes es g es bes   g b d f d b
g b c es d c        d fis g a bes g
fis g a es d c      bes c d a' fis g
c, es fis a fis es  c es c a c fis
}
  \alternative {
  { g16 d b g b d   g4. }           % THIS is bar 16;
  { g16 d b g b d   g4. }           % THIS is the alternative bar 16!
  }
  \pageBreak
  \repeat volta 2 {
  \stemDown
g,16( b d g d b)    g( b d f d b)    % THIS BAR should be numbered 17; 
however, it is 18!
g b c es c b        c es g c g f
g bes! g e des c    bes c e g f e
c e f as f c 
  \stemUp           f, g as c as f
des f bes des c bes
  \stemDown         a c es ges f es
f a bes as ges f    es ges f es des c

des c bes a bes e   f g as f c e
f as c as f e       f as f c as g
  \stemUp
f g as d as g
  \stemDown         as bes c es d c
bes c d f d c       d es f as g f
g f es d c es       as g f es d c
g b d f d b         g b d g d b
g b c es d c        g' f es d c b
c e f as g f        c' g es g c, es
as c, f as f d      b d f d b g
  \stemUp
es' c bes! as g f   es as g f es d
c f as c as f       d f g bes g es
  \stemDown
f as des f des b    g as' g f es d
  \stemUp
c b a g f d'        es, d es c' d, b'
c2.
  }
}

SicilianoB =  \relative c {
  \key c \minor
  \time 6/8
  \clef bass

  \repeat volta 2 { 
  \stemDown
c8( es g)    bes,( es g)
  \stemUp
as,( c f)    g,( bes e)
f,( as c)    es,( as c)
d, f as      c, f as
  \stemDown
b f' as      g, d' g
c, es g      bes, es g
  \stemUp
as, c f      g, bes es
  \stemDown
f as c       es, as c
d, f as      es f g
  \stemUp
as, d f      a, c es
  \stemDown
bes es f     bes, d as'
es g bes     d, g b
c, es g      bes,! d g
  \stemUp
a, c es      g, bes es
fis, a c     d, a' d
}
  \alternative {
  { g,4.~ g16 b d f d b }
  { g2. }
  }

  \repeat volta 2 {
  \stemUp
g8 b d \stemDown g b d
c es g       g, c es
e, g bes     c, g' c
  \stemUp
f,, as c     as c f
  \stemDown
bes, f' bes  c, es a
des, f bes   c, es as
bes, des g   c, f c'
  \stemUp
f,, as c     as c f
  \stemDown
bes, d bes'  c, es as
d, f as      bes, d bes'
es, g c      f, as d
g, b d       f, b d
es, g c      c, es g
  \stemUp
as, c f      g, c es
f, c' d       g, b g'
c, es g      bes, es g
as, c d      g, bes es
f, as f'     es, g c
d, c' b      c es, g
c16 es c g es g    c,4.
  }
}



\score {
\new PianoStaff <<
\set PianoStaff.instrumentName = "Cembalo"
\new Staff = "upper" << \SicilianoS >>
\new Staff = "lower" << \SicilianoB >>
>>

\layout { }
\midi { }
}