[Clp] Memory corruption writing ClpSimplex::savedSolution_ / ClpSimplex::saveStatus_

[John J Forrest]

Will fix at weekend.


                                                                                             
  From:       "Sebastian Theophil" <stheophil at think-cell.com>                                
                                                                                             
  To:         <clp at list.coin-or.org>                                                         
                                                                                             
  Date:       08/19/2009 08:52 AM                                                            
                                                                                             
  Subject:    [Clp] Memory corruption writing ClpSimplex::savedSolution_ /              
              ClpSimplex::saveStatus_                                                        
                                                                                             
  Sent by:    clp-bounces at list.coin-or.org                                                   
                                                                                             





Hi,


I have a reproducible crash using the latest Clp trunk. I have not found
a simple reproduction so far but I think I have figured out how the
error occurs:

OsiClpSolverInterface solver;
solver.setupForRepeatedUse(2);

// Setup problem with M rows / N columns

solver.initialSolve(); // <- may internally call modelPtr_->dual(0, 7)

// now solver.modelPtr_->saveStatus_ and savedSolution still exist
having M+N entries
// Change problem size to M' > M and N' > N
// ClpModel::resize resizes many arrays but of course not saveStatus_
and savedSolution_

// if this goes down to statusOfProblemInPrimal / statusOfProblemInDual,
saveStatus_ and savedSolution_ are overwritten with M'+N' entries
solver.initialSolve();


It seems to me, the error is not resizing or deleting saveStatus_ and
savedSolution_ when the problem size changes. Is there a simple fix to
this problem?

Regards
Sebastian

--
Sebastian Theophil . stheophil at think-cell.com
Software Engineer

think-cell Software GmbH . Invalidenstr. 34 . 10115 Berlin, Germany
http://www.think-cell.com . phone +49-30-666473-10 . toll-free (US)
+1-800-891-8091
Directors: Dr. Markus Hannebauer, Dr. Arno Schoedl . Amtsgericht
Berlin-Charlottenburg, HRB 85229


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