From 5e74610d0e111ff7dd70de4cfa4023c5d29f2127 Mon Sep 17 00:00:00 2001
From: Ian Bell <ian.h.bell@gmail.com>
Date: Thu, 5 Mar 2015 21:47:36 -0700
Subject: [PATCH] Fix unexplained crashes with setting of reference state; See
 #524

---
 include/Helmholtz.h                           |  2 +-
 .../Helmholtz/HelmholtzEOSMixtureBackend.cpp  | 19 +++++--------------
 src/CoolProp.cpp                              |  5 +----
 src/Tests/CoolProp-Tests.cpp                  |  2 +-
 4 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/include/Helmholtz.h b/include/Helmholtz.h
index c1f20fde60..848064e39f 100644
--- a/include/Helmholtz.h
+++ b/include/Helmholtz.h
@@ -584,7 +584,7 @@ class IdealHelmholtzEnthalpyEntropyOffset : public BaseHelmholtzTerm{
     IdealHelmholtzEnthalpyEntropyOffset(CoolPropDbl a1, CoolPropDbl a2, const std::string &ref):a1(a1),a2(a2),reference(ref),enabled(true) {}
 
     // Set the values in the class
-    void set(CoolPropDbl a1, CoolPropDbl a2, const std::string &ref){this->a1 = a1; this->a2 = a2; this->reference = ref; enabled = true;}
+    void set(CoolPropDbl a1, CoolPropDbl a2, const std::string &ref){this->a1 += a1; this->a2 += a2; this->reference = ref; enabled = true;}
 
     //Destructor
     ~IdealHelmholtzEnthalpyEntropyOffset(){};
diff --git a/src/Backends/Helmholtz/HelmholtzEOSMixtureBackend.cpp b/src/Backends/Helmholtz/HelmholtzEOSMixtureBackend.cpp
index c4553466ed..055881e54b 100644
--- a/src/Backends/Helmholtz/HelmholtzEOSMixtureBackend.cpp
+++ b/src/Backends/Helmholtz/HelmholtzEOSMixtureBackend.cpp
@@ -37,11 +37,8 @@ static int deriv_counter = 0;
 namespace CoolProp {
 
 HelmholtzEOSMixtureBackend::HelmholtzEOSMixtureBackend(const std::vector<std::string> &component_names, bool generate_SatL_and_SatV) {
-    std::vector<CoolPropFluid> components;
-    components.resize(component_names.size());
-
-    for (unsigned int i = 0; i < components.size(); ++i)
-    {
+    std::vector<CoolPropFluid> components(component_names.size());
+    for (unsigned int i = 0; i < components.size(); ++i){
         components[i] = get_library().get(component_names[i]);
     }
 
@@ -64,18 +61,12 @@ void HelmholtzEOSMixtureBackend::set_components(const std::vector<CoolPropFluid>
     // Copy the components
     this->components = components;
     this->N = components.size();
-
-    if (components.size() == 1){
-        is_pure_or_pseudopure = true;
+    
+    is_pure_or_pseudopure = (components.size() == 1);
+    if (is_pure_or_pseudopure){
         mole_fractions = std::vector<CoolPropDbl>(1, 1);
     }
     else{
-        is_pure_or_pseudopure = false;
-    }
-
-    // Set the excess Helmholtz energy if a mixture
-    if (!is_pure_or_pseudopure)
-    {
         // Set the mixture parameters - binary pair reducing functions, departure functions, F_ij, etc.
         set_mixture_parameters();
     }
diff --git a/src/CoolProp.cpp b/src/CoolProp.cpp
index ee4aa3170f..e0ddfefbd8 100644
--- a/src/CoolProp.cpp
+++ b/src/CoolProp.cpp
@@ -704,9 +704,7 @@ double saturation_ancillary(const std::string &fluid_name, const std::string &ou
 }
 void set_reference_stateS(const std::string &Ref, const std::string &reference_state)
 {
-    std::vector<std::string> _comps(1, Ref);
-    CoolProp::HelmholtzEOSMixtureBackend HEOS(_comps);
-
+    CoolProp::HelmholtzEOSMixtureBackend HEOS(std::vector<std::string>(1,Ref));
     if (!reference_state.compare("IIR"))
     {
         HEOS.update(QT_INPUTS, 0, 273.15);
@@ -741,7 +739,6 @@ void set_reference_stateS(const std::string &Ref, const std::string &reference_s
         double deltas = HEOS.smass() - 0; // offset from 0 kJ/kg/K entropy
         double delta_a1 = deltas/(HEOS.gas_constant()/HEOS.molar_mass());
         double delta_a2 = -deltah/(HEOS.gas_constant()/HEOS.molar_mass()*HEOS.get_reducing_state().T);
-        if (get_debug_level() > 5){std::cout << format("[set_reference_stateD] delta_a1 %g delta_a2 %g\n",delta_a1, delta_a2);}
         // Change the value in the library for the given fluid
         set_fluid_enthalpy_entropy_offset(Ref, delta_a1, delta_a2, "NBP");
     }
diff --git a/src/Tests/CoolProp-Tests.cpp b/src/Tests/CoolProp-Tests.cpp
index adbbe7c65f..4714ee9af2 100644
--- a/src/Tests/CoolProp-Tests.cpp
+++ b/src/Tests/CoolProp-Tests.cpp
@@ -1439,7 +1439,7 @@ TEST_CASE("Test that reference states yield proper values using low-level interf
         }
     }
 }
-TEST_CASE("Test that reference states are correct", "[reference_states_states]")
+TEST_CASE("Test that reference states are correct", "[reference_states]")
 {
     std::vector<std::string> fluids = strsplit(CoolProp::get_global_param_string("fluids_list"),',');
     for (std::size_t i = 0; i < fluids.size(); ++i)