GitLab

Steps to reproduce

digraph G {
    subgraph cluster_1 {
        a;
    }
    subgraph cluster_2 {
        b -> c1;
        b -> c2;
    }
    a -> b;
}

dot -O -Tpng first_node_in_cluster_causes_left_align.dot

Expected Behaviour

Nodes a and b are centered between c1 and c2, i.e. rendered the same as these variations:

• Still two subgraphs, but three leaf nodes instead of two.
  • Input

    digraph G {
        subgraph cluster_1 {
            a;
        }
        subgraph cluster_2 {
            b -> c1;
            b -> c2;
            b -> c3;
        }
        a -> b;
    }

  • Output
• Two leaf nodes, but first node not in a subgraph.
  • Input

    digraph G {
        subgraph cluster_2 {
            b -> c1;
            b -> c2;
        }
        a -> b;
    }

  • Output
• Two leaf nodes, but only first node in a subgraph.
  • Input

    digraph G {
        subgraph cluster_1 {
            a;
        }
        a -> b;
        b -> c1;
        b -> c2;
    }

  • Output

Actual Behaviour

Nodes a and b are left-aligned with c1.

OS Version

Ubuntu 20.04

Graphviz Version

dot - graphviz version 2.43.0 (0)