From 674adbd59250781831ee2c9b79ef525260d277da Mon Sep 17 00:00:00 2001
From: arvidn <arvid@libtorrent.org>
Date: Mon, 6 Nov 2017 13:18:47 +0100
Subject: [PATCH] add test to expose undefined behaviors endian_buffer when
 used with signed integers

---
 test/buffer_test.cpp | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/test/buffer_test.cpp b/test/buffer_test.cpp
index 803936a..ffe79ac 100644
--- a/test/buffer_test.cpp
+++ b/test/buffer_test.cpp
@@ -18,6 +18,7 @@
 #include <boost/cstdint.hpp>
 #include <iostream>
 #include <sstream>
+#include <limits>
 
 using namespace boost::endian;
 using std::cout;
@@ -198,6 +199,23 @@ namespace
     std::cout << "test construction and assignment" << std::endl;
   }
 
+  template <typename Int>
+  void test_boundary_values()
+  {
+    endian_buffer<order::big, Int, sizeof(Int) * CHAR_BIT, align::no> bmax(
+      std::numeric_limits<Int>::max());
+    endian_buffer<order::big, Int, sizeof(Int) * CHAR_BIT, align::no> bmin(
+      std::numeric_limits<Int>::min());
+    endian_buffer<order::little, Int, sizeof(Int) * CHAR_BIT, align::no> lmax(
+      std::numeric_limits<Int>::max());
+    endian_buffer<order::little, Int, sizeof(Int) * CHAR_BIT, align::no> lmin(
+      std::numeric_limits<Int>::min());
+
+    BOOST_TEST(bmax.value() == std::numeric_limits<Int>::max());
+    BOOST_TEST(bmin.value() == std::numeric_limits<Int>::min());
+    BOOST_TEST(lmax.value() == std::numeric_limits<Int>::max());
+    BOOST_TEST(lmin.value() == std::numeric_limits<Int>::min());
+  }
 }  // unnamed namespace
 
 //--------------------------------------------------------------------------------------//
@@ -230,6 +248,13 @@ int cpp_main(int, char *[])
   test_inserter_and_extractor();
   test_construction_and_assignment();
 
+  test_boundary_values<signed int>();
+  test_boundary_values<unsigned int>();
+  test_boundary_values<signed short>();
+  test_boundary_values<unsigned short>();
+  test_boundary_values<signed char>();
+  test_boundary_values<unsigned char>();
+
   cout << "  done" << endl;
 
   return ::boost::report_errors();