From b96ed7b984852d7d8922bcd0b0af1b2a05e2c825 Mon Sep 17 00:00:00 2001
From: Daniel James <daniel@calamity.org.uk>
Date: Sat, 28 May 2005 12:10:33 +0000
Subject: [PATCH] Check errno after calling frexp - this is pretty slow and
 unecessary on most platforms, but this close to release it seems better to be
 over cautious.

[SVN r29255]
---
 include/boost/functional/hash/hash.hpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/boost/functional/hash/hash.hpp b/include/boost/functional/hash/hash.hpp
index 81ff1dd..0ff794e 100644
--- a/include/boost/functional/hash/hash.hpp
+++ b/include/boost/functional/hash/hash.hpp
@@ -20,6 +20,7 @@
 #include <cmath>
 #include <string>
 #include <functional>
+#include <errno.h>
 #include <boost/limits.hpp>
 #include <boost/functional/detail/float_functions.hpp>
 #include <boost/detail/workaround.hpp>
@@ -264,7 +265,9 @@ namespace boost
         inline std::size_t float_hash_value(T v)
         {
             int exp = 0;
+            errno = 0;
             v = boost::hash_detail::call_frexp(v, &exp);
+            if(errno) return 0;
 
             std::size_t seed = 0;