From 4ca1a5e980ef60fde7cdb9216fcdaa55d0d33a7b Mon Sep 17 00:00:00 2001
From: Ian Bell <ian.h.bell@gmail.com>
Date: Thu, 11 Jun 2015 19:46:15 -0600
Subject: [PATCH] Predefined mixtures work with State class ; closes #697

---
 wrappers/Python/CoolProp/CoolProp.pyx | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/wrappers/Python/CoolProp/CoolProp.pyx b/wrappers/Python/CoolProp/CoolProp.pyx
index ec0edc0a0c..edc84f4145 100644
--- a/wrappers/Python/CoolProp/CoolProp.pyx
+++ b/wrappers/Python/CoolProp/CoolProp.pyx
@@ -530,6 +530,7 @@ cdef class State:
 
         cdef object _Fluid = Fluid
         cdef object _backend = backend
+        cdef bint set_fractions = False
         new_fluid = []
         fracs = []
         if '[' in _Fluid and ']' in _Fluid:
@@ -539,11 +540,11 @@ cdef class State:
                 new_fluid.append(fluid)
                 fracs.append(float(frac.strip(']')))
             _Fluid = '&'.join(new_fluid)
-        else:
-            fracs = [1]
+            set_fractions = True
         
         self.pAS = AbstractState(_backend, _Fluid)
-        self.pAS.set_mole_fractions(fracs)
+        if set_fractions:
+            self.pAS.set_mole_fractions(fracs)
 
     cpdef update_ph(self, double p, double h):
         """