sync with internal code; minor changes

ortools/base/file.cc

@@ -13,6 +13,7 @@
 
 #include <sys/stat.h>
 #include <sys/types.h>
+#include "ortools/base/join.h"
 #if defined(_MSC_VER)
 #include <io.h>
 #define access _access
@@ -27,7 +28,6 @@
 
 #include "ortools/base/file.h"
 #include "ortools/base/logging.h"
-#include "ortools/base/join.h"
 
 File::File(FILE* const f_des, const std::string& name) : f_(f_des), name_(name) {}
 

ortools/linear_solver/linear_solver.cc

@@ -312,12 +312,12 @@ void MPVariable::SetInteger(bool integer) {
   }
 }
 
-// ----- Version -----
+// ----- Interface shortcuts -----
+
+bool MPSolver::IsMIP() const { return interface_->IsMIP(); }
 
 std::string MPSolver::SolverVersion() const { return interface_->SolverVersion(); }
 
-// ---- Underlying solver ----
-
 void* MPSolver::underlying_solver() { return interface_->underlying_solver(); }
 
 // ---- Solver-specific parameters ----
@@ -920,9 +920,9 @@ MPSolver::ResultStatus MPSolver::Solve(const MPSolverParameters& param) {
 
   MPSolver::ResultStatus status = interface_->Solve(param);
   if (FLAGS_verify_solution) {
-    if (status != MPSolver::OPTIMAL) {
-      VLOG(1) << "--verify_solution enabled, but the solver did not find an"
-              << " optimal solution: skipping the verification.";
+    if (status != MPSolver::OPTIMAL && status != MPSolver::FEASIBLE) {
+      VLOG(1) << "--verify_solution enabled, but the solver did not find a"
+              << " solution: skipping the verification.";
     } else if (!VerifySolution(
                     param.GetDoubleParam(MPSolverParameters::PRIMAL_TOLERANCE),
                     FLAGS_log_verification_errors)) {

ortools/linear_solver/linear_solver.h

@@ -216,6 +216,8 @@ class MPSolver {
   // targets that you linked).
   static bool SupportsProblemType(OptimizationProblemType problem_type);
 
+  bool IsMIP() const;
+
   std::string Name() const {
     return name_;  // Set at construction.
   }

ortools/linear_solver/linear_solver.proto

@@ -47,7 +47,6 @@ package operations_research;
 // MPVariableProto furthermore stores:
 //  - The coefficient of the variable in the objective.
 //  - Whether the variable is integer.
-//  - Whether the variable domain is {0} union [lower_bound, upper_bound].
 message MPVariableProto {
   // lower_bound must be <= upper_bound.
   optional double lower_bound = 1 [default = -inf];
@@ -97,7 +96,7 @@ message MPConstraintProto {
   optional bool is_lazy = 5 [default = false];
 }
 
-// This message encode a partial (or full) assignment of the variables of a
+// This message encodes a partial (or full) assignment of the variables of a
 // MPModelProto problem. The indices in var_index should be unique and valid
 // variable indices of the associated problem.
 message PartialVariableAssignment {

ortools/lp_data/lp_utils.h

@@ -310,6 +310,11 @@ class SumWithOneMissing {
     ++num_infinities_;
   }
 
+  Fractional Sum() const {
+    if (num_infinities_ > 0) return Infinity();
+    return sum_.Value();
+  }
+
   Fractional SumWithout(Fractional x) const {
     if (IsFinite(x)) {
       if (num_infinities_ > 0) return Infinity();