Spacing issue after Mark and TextScript

[David Sumbler]

%%%%%%%%%%%%%%%%%%%
\version "2.19.81"

#(set-global-staff-size 12)

indent = #0

{ \textLengthOn
  \time 5/4
  r2 r4.
  \override Score.RehearsalMark.self-alignment-X = #-1
  \override Score.RehearsalMark.font-size = #5
  \mark \markup {"After the thirty-third encore, the Emperor arose."}
  \hide TextScript
  r8\fermata_"mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm"
  r4 |
%%%  \noBreak
  R4*5 | R4*5 | R4*5 |
}
%%%%%%%%%%%%%%%%%%%

When the above is compiled, the spacing for notes/rests after the Mark
and TextScript is increased.  This becomes even more obvious if
\noBreak is uncommented: the final crotchet rest of the first bar and
the whole bar rest of the second now take up so much horizontal space
that the line runs outside of the right-hand margin, as is shown in the
attached image.  Meanwhile the rests at the start of the first bar are
squashed together to make room for the unnecessary empty spaces later
in the line.  Things are restored to normal after a line break.

If I remove either the RehearsalMark or the TextScript, the problem
disappears.  The purpose of the textscript is to prevent the crotchet
rest appearing before the "Mark" is finished.

I have used the same kind of structure in numerous other places in this
piece without problems, and despite nearly a day of experimentation I
can't see why this case behaves differently.  (There are reasons for
presenting these texts as Marks rather than Text attached to a rest,
but they are not relevant to the problem.)

Any suggestions?  Is there perhaps a way of resetting the spacing
parameters to something sensible?

David

test.pdf
Description: Adobe PDF document