pdf changes every few compilations, although changing nothing

[Thomas Morley]

Hi all,

with the code below I experienced some pretty strange behaviour.

The visual output changes every few compilations, although I changed _nothing_!!
In average two times in 10 compilations.


Furthermore:
While uncommenting the second example things change again:
First example prints correct, second always wrong.
Then commenting first example causes always correct output for the second.


I use self-compiled 2.19.60 from
commit 777ce245ecf9041a98d977f017c10b4edabaec04
Author: Phil Holmes <address@hidden>
Date:   Mon Apr 10 08:28:15 2017 +0100

    Release: bump VERSION.


I'm aware there were some recent changes to the bracket code and the
dependencies of TupletBracket/TupletNumber.
Admittedly my own code is a brute-force override. Something wrong
there or with the recent changes?

Also, my code is not a minimal example, sorry for that, I keep trying
to reduce it.



\version "2.19.60"

\paper { ragged-right = ##t }

tst = {
    \override TupletBracket.stencil =
    #(lambda (grob)
       (let* ((orig (ly:grob-original grob))
              (siblings (if (ly:grob? orig)
                            (ly:spanner-broken-into orig) '()))
              (staff-space (ly:staff-symbol-staff-space grob))
              (x-pos (ly:grob-property grob 'X-positions))
              (x-length (interval-length x-pos))
              )
         (if (or (and (pair? siblings)
                      (equal? grob (car siblings)))
                 (null? siblings))
             (let* ((tuplet-number (ly:grob-object grob 'tuplet-number))
                    (text-stil
                      (grob-interpret-markup grob
                        #{ \markup \vcenter "Col Whatever" #}))
                    (text-stil-y-ext (ly:stencil-extent text-stil Y))
                    (text-stil-x-ext (ly:stencil-extent text-stil X))
                    (text-stil-x-length (interval-length text-stil-x-ext))
                    ;; value for y-extents of the new text-stencil.
                    ;; ensure correlation to staff-space, some additional
                    ;; padding is done later
                    (half-text-y
                      (ceiling (/ (cdr text-stil-y-ext) staff-space)))
                    (new-text-stil
                      (stencil-whiteout-box
                        (ly:make-stencil
                          (ly:stencil-expr text-stil)
                          (ly:stencil-extent text-stil X)
                          (symmetric-interval half-text-y))
                         ;; my choice:
                         (/ staff-space 4))))

               (if (< (+ (car x-pos) text-stil-x-length) (cdr x-pos))
                   (ly:grob-set-property! grob 'X-positions
                     (cons (+ (car x-pos) text-stil-x-length)
                           (cdr x-pos))))

               (ly:grob-set-property! tuplet-number 'X-extent empty-interval)
               (ly:grob-set-property! tuplet-number 'stencil new-text-stil)
               (ly:grob-set-property! tuplet-number 'Y-offset 0)
               (ly:grob-set-property! tuplet-number 'X-offset 0));
             (ly:grob-suicide! (ly:grob-object grob 'tuplet-number)))

         ;; adjusting the values by 'staff-space' is my choice for nicer
         ;; paddings in X-direction.
         (ly:stencil-translate-axis
           (grob-interpret-markup grob
             #{
                \markup
                  \draw-squiggle-line
                    #3 %% squiggle-length
                    #(cons (- x-length (* 1.5 staff-space)) 0) %% dest
                    ##t %% eq-end?
             #})
           (+ (/ staff-space 2) (car x-pos))
           X)))
    }

%%{
{
    \tst
    \set tupletFullLength = ##t

    \key cis \major
    \tuplet 1/1 {
      \hideNotes
      c1 c1 c1 c1
      \repeat unfold 30 c'1
      s1*20
      r2
      \unHideNotes
    }
    c'2 c'1
}
%}
%{
{
    \tst
    \set tupletFullLength = ##t
    \tuplet 1/1 { c'1 c'1 c' c' c' }
}
%}




Thanks,
  Harm