From cf9a69c227dced01874be7cc121ba38453a85c31 Mon Sep 17 00:00:00 2001
From: Ali Sinan Saglam <asinansaglam@gmail.com>
Date: Thu, 20 Dec 2018 12:36:41 -0500
Subject: [PATCH] Changed how the t_start value is ensured to be equal to the
 last end point (if given) using a tolerance of 1e-15. This fixes an issue
 where the t_start value and the end point are the same but "==" operator
 returns false due to machine precision error and the simulation fails to run.

---
 bng2/Perl2/BNGAction.pm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/bng2/Perl2/BNGAction.pm b/bng2/Perl2/BNGAction.pm
index 29cc3be8..a294c5da 100644
--- a/bng2/Perl2/BNGAction.pm
+++ b/bng2/Perl2/BNGAction.pm
@@ -421,13 +421,14 @@ sub simulate
 
     # Set start time for trajectory
     my $t_start;
+    my $tol=1e-15;
     if ( defined $params->{t_start} )
     {
         $t_start = $params->{t_start};        
         # if this is a continuation, check that model time equals t_start
         if ($continue)
         {
-            unless ( defined($model->Time)  and  ($model->Time == $t_start) )
+            unless ( defined($model->Time)  and  (abs($model->Time - $t_start) < $tol) )
             {  return "t_start must equal current model time for continuation.";  }
         }
     }