Created attachment 818742 [details]
testcase

With 

> dot -Tps -o /dev/null /tmp/tmpz0r863kc
Segmentation fault (core dumped)

#0  0x00007f91882ada93 in make_regular_edge
    (et=10, cnt=1, ind=<optimized out>, edges=0x55b288ed9980, P=0x55b288f28710,
sp=0x7ffe484a84e0, g=0x55b28759f580) at dotsplines.c:1825
#1  0x00007f91882ada93 in _dot_splines
    (g=g@entry=0x55b28759f580, normalize=normalize@entry=1) at dotsplines.c:459
#2  0x00007f91882b270a in dot_splines (g=g@entry=0x55b28759f580)
    at dotsplines.c:520
#3  0x00007f918829ecbd in dotLayout (g=g@entry=0x55b28759f580) at dotinit.c:336
#4  0x00007f918829f4a0 in doDot (g=0x55b28759f580) at dotinit.c:463
#5  0x00007f918829f4a0 in dot_layout (g=0x55b28759f580) at dotinit.c:509
#6  0x00007f918e42f03b in gvLayoutJobs () at /usr/lib64/libgvc.so.6
#7  0x000055b286b2306f in main (argc=<optimized out>, argv=<optimized out>)
    at dot.c:134

using graphviz-2.40.1-lp151.6.3.1.x86_64

On Tumbleweed with graphviz-2.40.1+git20190410.b0871968d-2.4.x86_64 it works
fine.