Number: 203
Title: Concentrate drops edges from two vertex cycles
Submitter: Alex Harper
Date: Fri Sep 20 15:58:21 2002
Subsys: Dot
Version: 1.8.9
System: x86-Linux-2.4.9 Redhat
Severity: major
Problem:
With edge concentration on dot drops a cyclic edge between two vertices in a cycle.

In previous versions (1.7.x releases) this was rendered correctly as a bidirectional edge between the vertices. In 1.8 (1.8.5 and 1.8.9 were tested) the edge is rendered as a one-way arrow. Turning off concentration eliminates the issue.

As for severity... since I saw no mention of changes to concentrate behavior in the changelog I'm assuming this is a bug.
Input: 

digraph G {
        /* Use edge concentration */
        concentrate=true;

1 [ label = "node1" ];
2 [ label = "node2" ];
1 -> 2;
2 -> 1;

} /* graph close */
Owner: *
Status: *