From ba7725fb5bc2bef69cd1927ec0c1bbc763cb103f Mon Sep 17 00:00:00 2001
From: Ray Speth <speth@mit.edu>
Date: Mon, 5 Nov 2012 19:26:11 +0000
Subject: [PATCH] Fixed a problem with the VCS equilibrium solver at constant
 HP or UP

A sign error when limiting the temperature step caused the solver to fail if
the initial temperature was higher than sqrt(Tlow*Thigh).

Cherry-picked from trunk (r1883).
---
 src/equil/vcs_MultiPhaseEquil.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/equil/vcs_MultiPhaseEquil.cpp b/src/equil/vcs_MultiPhaseEquil.cpp
index ea91b7076..fe13a17e9 100644
--- a/src/equil/vcs_MultiPhaseEquil.cpp
+++ b/src/equil/vcs_MultiPhaseEquil.cpp
@@ -293,7 +293,7 @@ int vcs_MultiPhaseEquil::equilibrate_HP(doublereal Htarget,
                 Tnew = sqrt(Tlow*Thigh);
                 dT = Tnew - Tnow;
                 if (dT < -200.) {
-                    dT = 200;
+                    dT = -200;
                 }
                 if (dT > 200.) {
                     dT = 200.;