[Bug-glpk] Assertion in ios_pcost_update

[Chris Matrakidis]

Andrew,

I managed to trigger the xassert(dx != 0.0) in ios_pcost_update (line
508 of glpios09.c). What I think happens is that the branching
variable has a value over 10000, so that tol_mip is smaller than the
product of tol_piv and the unscaled variable, so it is a candidate for
branching but doesn't change value afterwards. The attached patch
papers over the symptom, but I'm not sure this is the best way.

Best Regards,

Chris Matrakidis

pcost_update.patch
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