bug in topo.py Topo.AddLink()

[alfsalte]

The function AddLink() in topo.py in class Topo is in my version like this:

def addLink( self, node1, node2, port1=None, port2=None,
             key=None, **opts ):
    """node1, node2: nodes to link together
       port1, port2: ports (optional)
       opts: link options (optional)
       returns: link info key"""
    if not opts and self.lopts:
        opts = self.lopts
    port1, port2 = self.addPort( node1, node2, port1, port2 )
    opts = dict( opts )
    opts.update( node1=node1, node2=node2, port1=port1, port2=port2 )
    self.g.add_edge(node1, node2, key, opts )
    return key

The last line should be removed and the line before it should get the return, like this:
..... other code...
opts.update( node1=node1, node2=node2, port1=port1, port2=port2 )
return self.g.add_edge(node1, node2, key, opts )

The key argument in is by default None and Multigraph.add_edge will change the key if it is None to the actual key value and return the actual key. AddLink also have key as None by default and the present code simply returns the input key even if it is None.

Instead it should return the key it gets from add_edge so that it returns the actual key used.

[jadinm]

The PR #895 will fix this issue when merged :)

[cheriimoya]

PR is merged, this can be closed @lantz