[Bonmin-tickets] [Bonmin] #11: Bub and fix in the Ipopt's ma57 solver interface

[Bonmin]

#11: Bub and fix in the Ipopt's ma57 solver interface
-----------------------+----------------------------------------------------
Reporter:  rodrigo     |       Owner:  pbonami
    Type:  defect      |      Status:  new    
Priority:  blocker     |   Component:  Bonmin 
 Version:  stable/0.1  |    Keywords:         
-----------------------+----------------------------------------------------
 Hi Andreas and Pierre,

 I've detected a small bug in the Ma57 linear solver interface in Ipopt
 that only shows up when using it iteratively through bonmin. Lines 328-341
 of the IpMa57SolverInterface.cpp files read as:


 {{{
 if (!warm_start_same_structure_) {
       dim_=0;
       nonzeros_=0;
       delete [] a_;
       delete [] wd_fact_;
       delete [] wd_ifact_;
       delete [] wd_iwork_;
       delete [] wd_keep_;
     }
     else {
       ASSERT_EXCEPTION(dim_>0 && nonzeros_>0, INVALID_WARMSTART,
                        "Ma57TSolverInterface called with
 warm_start_same_structure, "
                        "but the problem is solved for the first time.");
     }

 }}}


 I think that when bonmin calls ipopt again for a new NLP iteration, and if
 it is using a warm start, then the pointers to a_ and  wd_* should not be
 deleted. I had been getting segmentation faults, but after commenting out
 all of the delete [] lines, the problems have gone away. What do you think
 guys?

 Thanks, hth.
   Rodrigo

-- 
Ticket URL: <https://projects.coin-or.org/Bonmin/ticket/11>
Bonmin <http://projects.coin-or.org/Bonmin>
Basic Open-source Nonlinear Mixed INteger programming