Crash when music of score starts with \pageBreak

[Richard Shann]

I came across a situation where LilyPond crashes caused by a badly
placed \pageBreak. I've chopped most of the music out of the example
but when I tried to remove more the crash stopped.
The error message ends:

Finding the ideal number of pages...
Fitting music on 1 page...lilypond: 
/home/gub/NewGub/gub/target/linux-64/src/lilypond-git.sv.gnu.org--lilypond.git-stable-2.22/lily/page-breaking.cc:1073:
 void Page_breaking::line_divisions_rec(vsize, const Line_division&, const 
Line_division&, Page_breaking::Line_division*): Assertion `my_index == 0' 
failed.
Exited with return code 6.

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\version "2.22.1"
MI = {
  r8 e'' g''8. f''16 e''8 d''16 c'' b'4-\trill 
}

MII = { \time 2/4
         \pageBreak 
         e''8( f'') g''( f'') |
         e''( d'') c''-\trill( b'8) | 
         c''( d'') e''( f'') | 
         e''4-\trill d''4 | 
%5
         e''8 c'' g'' e'' | 
         a'' c''' b'' g'' | 
         a''4 fis''-\trill | 
         g''2 | 
         e''8( f'') g''( f'') | 
%10
         e''( d'') c''( b') | 
         c''( d'') e''( f'') | 
         e''4-\trill d''4 | 
         e''8( c'') g''( e'') | 
         a''( b'') c'''( c'') | 
%15
         d''4 b'-\trill | 
         c''2  \break \bar ":..:" e''8( f'') g''( a'') | 
         g''4 c'''8( b'') | 
         c'''( g'') a''( f'') | 
%20
         e''4-\trill d''4 | 
         e''8( d'') c''( b') | 
         c''( d'') e''( d'') | 
         d''4( c''8-\trill) b'8 | 
         a'2-\trill | 
%25
         b'8( c'') d''( e'') | 
         d''( e'') fis''( g'') | 
         b'4 a'-\trill | 
         g'2 | 
         d''8( e'') c''( e'') | 
%30
         e''( f'') d''( f'') 
}

\score {\MI} 

\score {\MII} 

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I think this bug will not be in some earlier version of LilyPond as the
file is an old one that at one time compiled ok.

Richard