#396 ASCIIDisplayer.lua example does not work

[Otfried Cheong]

The first example in the section The Display Layer of Chapter Graph Drawing does not work. It calls the method InterfaceToDisplay.pushPhase, which is not defined (and in fact a grep on the entire subtree graphdrawing/lua found no other match for pushPhase.

I assume pushPhase should simply be pushOption, but it still doesn't work:

lua: ...graphdrawing/lua/pgf/gd/interface/InterfaceToDisplay.lua:213: ...z/tex/generic/pgf/graphdrawing/lua/pgf/gd/model/Path.lua:635: attempt to index local 'prev' (a nil value)
stack traceback:
    [C]: in function 'assert'
    ...graphdrawing/lua/pgf/gd/interface/InterfaceToDisplay.lua:213: in function 'resumeGraphDrawingCoroutine'
    ...graphdrawing/lua/pgf/gd/interface/InterfaceToDisplay.lua:182: in function 'runGraphDrawingAlgorithm'

This is for the latest release from sourceforge, pgf_3.0.1.tds.zip (although the README inside the zip file is still called README-3.0.0.

[Otfried Cheong]

After a bit of digging, it seems that pushPhase should simply be pushOption, and instead of "main" one can just write nil, I guess (it's a valueless key, right?)

The crash is happens in LayoutPipeline:cutEdges, and it happens because the nodes are created with a nil value for their path. The problem goes away if one sets the option cut policy to none.