Re: [Bug-glpk] glpk 4.39: Assertion failed: col->type == GLP_FX

[Andrew Makhorin]

> with the attached lp, I get an assert in glpnpp01.c at line 634:

> GLPSOL: GLPK LP/MIP Solver 4.39
> Reading problem data from `glpk_nppassertfail.mps'...
> Problem: <none_lo
> Objective: R0000000
> 7 rows, 26 columns, 38 non-zeros
> 75 records were read
> Original LP has 7 rows, 26 columns, 38 non-zeros
> Presolved LP has 5 rows, 6 columns, 12 non-zeros
> Scaling...
>  A: min|aij| =  1.000e+00  max|aij| =  1.000e+00  ratio =  1.000e+00
> Problem data seem to be well scaled
> Constructing initial basis...
> Size of triangular part = 5
>       0: obj =   0.000000000e+00  infeas =  9.000e+02 (0)
> *     4: obj =   1.809000000e+02  infeas =  0.000e+00 (0)
> *     5: obj =   1.784250000e+02  infeas =  0.000e+00 (0)
> OPTIMAL SOLUTION FOUND
> Assertion failed: col->type == GLP_FX
> Error detected in file ../../glpk/src/glpnpp01.c at line 634

Thank you for your bug report.

The bug will be fixed in a next release of the package.

To fix the bug right now please change line 808 in file glpnpp02.c
(function npp_empty_col):

         info->stat = GLP_NS;

to the following one:

         info->stat = GLP_NF;