Crash when adding third grace note

Reproduce as follows using the attached file:
repeat three times:
- select the second 1/8 note in the pickup measure
- open the grace note palette
- double click grace 32nd

Now tickMod is zero, leading to a divide by zero exception. Note that this is apparently context-dependent, as I could not reproduce this behaviour using another file.

As I am not familiar with the beam layout algorithms, I cannot easily solve this myself.

GDB output:

Program received signal EXC_ARITHMETIC, Arithmetic exception.
0x00000001005db2ef in Ms::Beam::layout2 (this=0x1141766b0, crl=@0x7fff5fbfba30, frag=0) at /Users/lvi/dev/MuseScore/libmscore/beam.cpp:1627
1627 int mod = tickNext % tickMod;
(gdb) bt
#0 0x00000001005db2ef in Ms::Beam::layout2 (this=0x1141766b0, crl=@0x7fff5fbfba30, frag=0) at /Users/lvi/dev/MuseScore/libmscore/beam.cpp:1627
#1 0x00000001005d9492 in Ms::Beam::layout (this=0x1141766b0) at /Users/lvi/dev/MuseScore/libmscore/beam.cpp:432
#2 0x00000001006be094 in Ms::Score::doLayout (this=0x113a24600) at /Users/lvi/dev/MuseScore/libmscore/layout.cpp:638
#3 0x00000001006359ea in Ms::Score::endCmd (this=0x113a24600) at /Users/lvi/dev/MuseScore/libmscore/cmd.cpp:120
#4 0x000000010044ec5f in Ms::Palette::mouseDoubleClickEvent (this=0x1104c2bf0, ev=0x7fff5fbfcc78) at /Users/lvi/dev/MuseScore/mscore/palette.cpp:333