Modifications have been made to improve the reliability of the IPM solver when cross-over is not always run - carried out for benchmarking purposes. This has required the run_crossover option that was previously Boolean to become a string with possible values "on", "off" and "choose". The latter results in crossover being run if the result of IPM without crossover is imprecise.
HiGHS will now allow a solution to be read from a file when running HiGHS from the command line, and handle the case where a user has supplied a partial (discrete) solution to a MIP. If the supplied solution is not feasible, HiGHS will fix the discrete variables and attempt to find a feasible assignment of the continuous variables by solving an LP.
If the incumbent model has discrete variables, then the MIP is solved regardless of the setting of the solve option. Previously if solve were "simplex" or "ipm" then the relaxation would be solved. To force the relaxation to be solved, set the (new) solve_relaxation option (default "false") to be true.
Various bug fixes, notably time limit introduced into redundant equations rule for presolve.