From bb7b446c6bd6afc8727fa77f208e411929987daa Mon Sep 17 00:00:00 2001
From: Ian Bell <ian.h.bell@gmail.com>
Date: Mon, 9 Mar 2015 23:44:38 -0600
Subject: [PATCH] Check if HS update deltas are valid numbers

---
 src/Backends/Helmholtz/Fluids/FluidLibrary.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Backends/Helmholtz/Fluids/FluidLibrary.h b/src/Backends/Helmholtz/Fluids/FluidLibrary.h
index ffa8386f..c0105239 100644
--- a/src/Backends/Helmholtz/Fluids/FluidLibrary.h
+++ b/src/Backends/Helmholtz/Fluids/FluidLibrary.h
@@ -1201,6 +1201,9 @@ public:
             std::map<std::size_t, CoolPropFluid>::iterator it2 = fluid_map.find(it->second);
             // If it is found
             if (it2 != fluid_map.end()){
+                if (!ValidNumber(delta_a1) || !ValidNumber(delta_a2) ){
+                    throw ValueError(format("Not possible to set reference state for fluid %s because offset values are NAN",fluid.c_str()));
+                }
                 it2->second.EOSVector[0].alpha0.EnthalpyEntropyOffset.set(delta_a1, delta_a2, ref);
             }
             else{