Incorrectly detected infeasibility with pre-solve turned off

[apfelix]

Hi,

as a workaround to #1958 I started using HiGHS with pre-solve turned off.

However, I found a model model for which infeasibility is reported when pre-solve is turned off: highs_model_for_debugging_infeasible_with_presolve_off.mps.txt Tested via highspy on version 1.7.2 and branch latest.

A solution is found by

• turning on pre-solve
• using SCIP
• using Gurobi

In contrast to #1958 I was able to find an instance with <1000 vars and constraints.