Remove shifting of short domain integer columns

Author: Opt-Mucca

highs/presolve/HPresolve.cpp

@@ -4465,25 +4465,6 @@ HPresolve::Result HPresolve::colPresolve(HighsPostsolveStack& postsolve_stack,
 
     // check if variable is implied integer
     HPRESOLVE_CHECKED_CALL(static_cast<Result>(convertImpliedInteger(col)));
-
-    // shift integral variables to have a lower bound of zero
-    if (model->integrality_[col] != HighsVarType::kContinuous &&
-        model->col_lower_[col] != 0.0 &&
-        (model->col_lower_[col] != -kHighsInf ||
-         model->col_upper_[col] != kHighsInf) &&
-        model->col_upper_[col] - model->col_lower_[col] > 0.5) {
-      // substitute with the bound that is smaller in magnitude and only
-      // substitute if bound is not large for an integer
-      if (std::abs(model->col_upper_[col]) > std::abs(model->col_lower_[col])) {
-        if (std::abs(model->col_lower_[col]) < 1000.5)
-          HPRESOLVE_CHECKED_CALL(transformColumn(postsolve_stack, col, 1.0,
-                                                 model->col_lower_[col]));
-      } else {
-        if (std::abs(model->col_upper_[col]) < 1000.5)
-          HPRESOLVE_CHECKED_CALL(transformColumn(postsolve_stack, col, -1.0,
-                                                 model->col_upper_[col]));
-      }
-    }
   }
 
   // dual fixing