From ff93cfbb9781b9ae31ef9b511f450aee3d1d27cc Mon Sep 17 00:00:00 2001
From: Laurent Perron <lperron@google.com>
Date: Tue, 18 Jun 2019 16:00:06 +0200
Subject: [PATCH] fix bug in rins

---
 ortools/sat/cp_model_lns.cc    |  7 ++-----
 ortools/sat/cp_model_solver.cc |  2 +-
 ortools/sat/rins.cc            | 11 ++++++++---
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/ortools/sat/cp_model_lns.cc b/ortools/sat/cp_model_lns.cc
index 8da4699251..408673e0b9 100644
--- a/ortools/sat/cp_model_lns.cc
+++ b/ortools/sat/cp_model_lns.cc
@@ -459,13 +459,8 @@ Neighborhood RelaxationInducedNeighborhoodGenerator::Generate(
   neighborhood.cp_model = helper_.ModelProto();
   neighborhood.is_generated = false;
 
-  const int num_model_vars = helper_.ModelProto().variables_size();
   SharedRINSNeighborhoodManager* rins_manager =
       model_->Mutable<SharedRINSNeighborhoodManager>();
-  std::vector<int> all_vars;
-  for (int i = 0; i < num_model_vars; ++i) {
-    all_vars.push_back(i);
-  }
   if (rins_manager == nullptr) {
     return neighborhood;
   }
@@ -481,6 +476,7 @@ Neighborhood RelaxationInducedNeighborhoodGenerator::Generate(
        rins_neighborhood_opt.value().fixed_vars) {
     int var = fixed_var.first.model_var;
     int64 value = fixed_var.second;
+    if (var >= neighborhood.cp_model.variables_size()) continue;
     if (!helper_.IsActive(var)) continue;
     neighborhood.cp_model.mutable_variables(var)->clear_domain();
     neighborhood.cp_model.mutable_variables(var)->add_domain(value);
@@ -493,6 +489,7 @@ Neighborhood RelaxationInducedNeighborhoodGenerator::Generate(
     int var = reduced_var.first.model_var;
     int64 lb = reduced_var.second.first;
     int64 ub = reduced_var.second.second;
+    if (var >= neighborhood.cp_model.variables_size()) continue;
     if (!helper_.IsActive(var)) continue;
     Domain domain = ReadDomainFromProto(neighborhood.cp_model.variables(var));
     domain = domain.IntersectionWith(Domain(lb, ub));
diff --git a/ortools/sat/cp_model_solver.cc b/ortools/sat/cp_model_solver.cc
index a306848091..690a605ebb 100644
--- a/ortools/sat/cp_model_solver.cc
+++ b/ortools/sat/cp_model_solver.cc
@@ -1302,7 +1302,7 @@ void SolveLoadedCpModel(const CpModelProto& model_proto,
           mapping->GetProtoVariableFromIntegerVariable(positive_var);
       rins_var.lp = gtl::FindWithDefault(*lp_dispatcher, positive_var, nullptr);
 
-      if (rins_var.lp != nullptr) {
+      if (rins_var.lp != nullptr && rins_var.model_var >= 0) {
         rins_vars->vars.push_back(rins_var);
       }
     }
diff --git a/ortools/sat/rins.cc b/ortools/sat/rins.cc
index 4b4920a53c..e0e7e69fe2 100644
--- a/ortools/sat/rins.cc
+++ b/ortools/sat/rins.cc
@@ -48,8 +48,9 @@ SharedRINSNeighborhoodManager::GetUnexploredNeighborhood() {
   // return the last added neighborhood and remove it.
   const RINSNeighborhood neighborhood = std::move(neighborhoods_.back());
   neighborhoods_.pop_back();
-  total_stored_vars_ -=
+  const int64 neighborhood_size =
       neighborhood.fixed_vars.size() + neighborhood.reduced_domain_vars.size();
+  total_stored_vars_ -= neighborhood_size;
   VLOG(1) << "total stored vars: " << total_stored_vars_;
   return neighborhood;
 }
@@ -113,8 +114,12 @@ void AddRINSNeighborhood(Model* model) {
     }
   }
 
-  model->Mutable<SharedRINSNeighborhoodManager>()->AddNeighborhood(
-      rins_neighborhood);
+  const int64 neighborhood_size = rins_neighborhood.fixed_vars.size() +
+                                  rins_neighborhood.reduced_domain_vars.size();
+  if (neighborhood_size > 0) {
+    model->Mutable<SharedRINSNeighborhoodManager>()->AddNeighborhood(
+        rins_neighborhood);
+  }
 }
 
 }  // namespace sat