Merge pull request #2464 from ERGO-Code/fix-2439

Fix 2439 and 2455

Author: jajhall

highs/mip/HighsDomain.cpp

@@ -3215,7 +3215,10 @@ bool HighsDomain::ConflictSet::explainInfeasibility() {
       HighsInt ninfmin;
       HighsCDouble minAct;
       globaldom.computeMinActivity(0, len, inds, vals, ninfmin, minAct);
-      assert(ninfmin == 0);
+      // This case should only happen when a globally unbounded column is
+      // bounded in the local domain, e.g., by a branching choice in some
+      // heuristic.
+      if (ninfmin > 0) return false;
 
       return explainInfeasibilityLeq(inds, vals, len, rhs, double(minAct));
     }

highs/mip/HighsMipSolverData.cpp

@@ -1120,6 +1120,11 @@ double HighsMipSolverData::transformNewIntegerFeasibleSolution(
     }
   }
 
+  const double transformed_solobj =
+      static_cast<double>(static_cast<HighsInt>(mipsolver.orig_model_->sense_) *
+                              mipsolver_quad_objective_value -
+                          mipsolver.model_->offset_);
+
   // Possible MIP solution callback
   if (!mipsolver.submip && feasible && mipsolver.callback_->user_callback &&
       mipsolver.callback_->active[kCallbackMipSolution]) {
@@ -1130,6 +1135,12 @@ double HighsMipSolverData::transformNewIntegerFeasibleSolution(
     assert(!interrupt);
   }
 
+  // Catch the case where the repaired solution now has worse objective
+  // than the current stored solution
+  if (transformed_solobj >= upper_bound && !sol.empty()) {
+    return transformed_solobj;
+  }
+
   if (possibly_store_as_new_incumbent) {
     // Store the solution as incumbent in the original space if there
     // is no solution or if it is feasible
@@ -1171,11 +1182,9 @@ double HighsMipSolverData::transformNewIntegerFeasibleSolution(
       return kHighsInf;
     }
   }
-  // return the objective value in the transformed space
-  if (mipsolver.orig_model_->sense_ == ObjSense::kMaximize)
-    return -double(mipsolver_quad_objective_value + mipsolver.model_->offset_);
 
-  return double(mipsolver_quad_objective_value - mipsolver.model_->offset_);
+  // return the objective value in the transformed space
+  return transformed_solobj;
 }
 
 double HighsMipSolverData::percentageInactiveIntegers() const {