[Bug-glpk] Bug in dual simplex phase I to II transition with perturbation

[Chris Matrakidis]

Andrew,

There is a bug in the dual simplex transition from phase I to phase II
when perturbation was applied - it may be that the perturbed problem
is dual infeasible while the unperturbed one is feasible, a case that
is not checked in the code. This happens with stat96v1 (downloaded
from http://www.sztaki.hu/~meszaros/public_ftp/lptestset/misc/ ).

The attached patch is an approach to fix this, but disables
perturbation for phase II in this case, which may not be desirable.


Best Regards,

Chris Matrakidis

dual.patch
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