EclSum doesn't read network vectors

[alifbe]

Network vectors from intersect are not imported.

This has been resolved in ResInsight in their local copy

OPM/ResInsight#8990

[eivindjahren]

The problem is that set_gen_keys does not assign a key to a network var so when you try to look up the var in EclSum by key, then you don't find any network vars.

https://github.com/equinor/ecl/blob/ed744e8b5c28510f41ca021c0318ba0208525e51/lib/ecl/smspec_node.cpp#L663

[eivindjahren]

I suggest doing the same fix as they did here:

https://github.com/OPM/ResInsight/blob/47f75b16760d74d2144d107d24d8e5e1da5436c0/ThirdParty/Ert/lib/ecl/smspec_node.cpp#L612