#5476 programming error/segfault while omitting Fingering.stencil with fingeringOrientations set 'left

[Palmer Ralph]

https://codereview.appspot.com/567560043

Thomas Morley wrote :

the following code is problematic

{
  \set fingeringOrientations = #'(left)
  \override Fingering #'stencil = ##f
  <g'-2 c''-4 >  %% chord needs two elements to trigger the bug
}

Versions 2.12.3 up to 2.16.2 print correctly, without error

Versions 2.18.2 up to 2.19.82 print correctly, but return:
programming error: Infinity or NaN encountered

Current master does:
Segmentation fault (core dumped)

[Valentin Villenave]

And this is what gdb has to say:

Box::is_empty (this=this@entry=0x0, a=a@entry=Y_AXIS) at /lilypond/flower/include/drul-array.hh:47
47    T const &operator [] (Direction d) const

I’m wondering if it isn’t another skyline problem; setting the Direction to up or down doesn’t segfault but setting it to a horizontal direction (either right or left) does.

I thought this illegal stencil Box would be passed by the New_fingering_engraver, but of the two following snippets, only the first one triggers the bug:

{
  \set strokeFingerOrientations = #'(right)
  \override StrokeFinger.stencil = ##f
  <g'-\rightHandFinger #2 c''-\rightHandFinger #4 >
}

{
  \set stringNumberOrientations = #'(right)
  \override StringNumber.stencil = ##f
  <g'\2 c''\4 >
}

A workaround it not set the stencil property to ##f but rather to #empty-stencil.

[Valentin Villenave]

Fix #5476: segfault when Fingering stencil set to #f.

https://codereview.appspot.com/567560043

[Anonymous]

Passes make, make check and a full make doc but the reg tests aren't good.

See:

https://cloud-u8zj2dc4b.yourownnet.eu/s/fD5Tjo2Frz3g9p5 (~1mb)

[Valentin Villenave]

Yowza. Not good indeed. Thanks for catching this James, I should’ve paid more attention!

[Valentin Villenave]

Fix regtests (conditional should only apply to horizontal fingerings)

https://codereview.appspot.com/567560043

[Anonymous]

Passes make, make check and a full make doc.

Reg test diffs attached

[Anonymous]

Patch on countdown for May 11th