osage: segmentation fault on same nodes in different clusters

Steps to reproduce

funs.dot:

digraph G {
subgraph "cluster_std" {
"622";
}
subgraph "cluster_uni" {
"622";
}
}

run osage funs.dot -Tpng -o funs.png

Expected Behaviour

make png file or report an error

Actual Behaviour

Segmentation fault (core dumped)

OS Version

Linux feelus-ubuntu-24-04 6.14.0-29-generic #29~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Aug 14 16:52:50 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

Graphviz Version

Ubuntu package: 2.43.0 (0)
Also compiled by me: 13.1.2 (20250808.2320) after

git clone https://gitlab.com/graphviz/graphviz.git
cd graphviz
git checkout 13.1.2
git reset --hard
git clean -fdx
./autogen.sh
mkdir build
mkdir inst
cd build
../configure --prefix=$PWD/../inst
make -j 4
make install
cd ../inst
bin/osage funs.dot -Tsvg -o funs.svg