From bed761e2c28315aaccf51058c42eef45b7c9c6a5 Mon Sep 17 00:00:00 2001
From: Jeremy Siek <jeremy.siek@gmail.com>
Date: Wed, 23 May 2001 16:40:46 +0000
Subject: [PATCH] added check for overflow

[SVN r10198]
---
 include/boost/graph/relax.hpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/boost/graph/relax.hpp b/include/boost/graph/relax.hpp
index 91291ae4..9c0e9971 100644
--- a/include/boost/graph/relax.hpp
+++ b/include/boost/graph/relax.hpp
@@ -55,6 +55,10 @@ namespace boost {
       D d_u = get(d, u), d_v = get(d, v);
       W w_e = get(w, e);
 
+      // workaround overflow problem, don't relax if d_u is close to inf
+      if (std::abs(std::numeric_limits<D>::max() - d_u) < std::abs(w_e))
+	return false;
+      
       if ( compare(combine(d_u, w_e), d_v) ) {
         put(d, v, combine(d_u, w_e));
 	put(p, v, u);