[Dot] Edge arrowhead and arrowtail inverted if splines=ortho is set.

Ported Issue from Mantis Original ID: 2565 Reported By: Raimy

SEVERITY: IMPORTANT Submitted: 2015-08-17 15:45:04

OS: WINDOWS

OS BUILD: 7 (64-BIT)

DESCRIPTION

If setting the edge direction to "both" and defining an arrowhead and an arrowtail different from "none" (see reproduction steps), these ends get mixed up (so, which is the head and which is the tail part of the edge) if splines=ortho is also defined.

STEPS TO REPRODUCE

Case 1 (without splines=ortho) - edge ends as expected

digraph Test {
    nodesep = 1.0;
    ranksep = 1.0;
    edge [dir = both, arrowhead = dot, arrowtail = curve, headlabel="Head", taillabel="Tail"];  
    A -> B;
    A -> C;
    D -> C; 
}

Case 2 (with splines=ortho set) - edge ends between A->B and D->C inverted

digraph Test {
    splines = ortho;
    nodesep = 1.0;
    ranksep = 1.0;
    edge [dir = both, arrowhead = dot, arrowtail = curve, headlabel="Head", taillabel="Tail"];  
    A -> B;
    A -> C;
    D -> C;
}

ADDITIONAL INFORMATION

Furthermore, if adding for example E -> C edge it will be displayed correctly (only A->B and D->C is wrong). If adding another F -> C edge, all edges with target node C are correct, but not A->B.

It somehow relates to the number of edges that have the target node C.