error_code wrapping std::error_code should never compare equal to error_code not wrapping std (because of hash_value.) Fixes #101.

include/boost/system/detail/error_code.hpp

@@ -403,7 +403,12 @@ public:
     {
 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
 
-        if( lhs.lc_flags_ == 1 && rhs.lc_flags_ == 1 )
+        bool s1 = lhs.lc_flags_ == 1;
+        bool s2 = rhs.lc_flags_ == 1;
+
+        if( s1 != s2 ) return false;
+
+        if( s1 && s2 )
         {
             std::error_code const& e1 = *reinterpret_cast<std::error_code const*>( lhs.d2_ );
             std::error_code const& e2 = *reinterpret_cast<std::error_code const*>( rhs.d2_ );
@@ -421,7 +426,13 @@ public:
     {
 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
 
-        if( lhs.lc_flags_ == 1 && rhs.lc_flags_ == 1 )
+        bool s1 = lhs.lc_flags_ == 1;
+        bool s2 = rhs.lc_flags_ == 1;
+
+        if( s1 < s2 ) return true;
+        if( s2 < s1 ) return false;
+
+        if( s1 && s2 )
         {
             std::error_code const& e1 = *reinterpret_cast<std::error_code const*>( lhs.d2_ );
             std::error_code const& e2 = *reinterpret_cast<std::error_code const*>( rhs.d2_ );

test/CMakeLists.txt

@@ -132,6 +132,8 @@ boost_test(TYPE run SOURCES std_interop_test15.cpp)
 
 boost_test(TYPE run SOURCES win32_generic_test.cpp)
 
+boost_test(TYPE run SOURCES ec_hash_value_test.cpp)
+
 # result
 
 set(BOOST_TEST_COMPILE_FEATURES cxx_std_11)

test/Jamfile.v2

@@ -160,6 +160,8 @@ run std_interop_test15.cpp ;
 
 run win32_generic_test.cpp ;
 
+run ec_hash_value_test.cpp ;
+
 # result
 
 import ../../config/checks/config : requires ;

test/ec_hash_value_test.cpp

@@ -0,0 +1,132 @@
+// Copyright 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/generic_category.hpp>
+#include <boost/system/system_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+#include <system_error>
+#endif
+
+namespace sys = boost::system;
+
+int main()
+{
+    // normal against normal (equal, system)
+    {
+        sys::error_code e2( 0, sys::system_category() );
+        sys::error_code e3( e2.value(), e2.category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal against normal (equal, generic)
+    {
+        sys::error_code e2( EINVAL, sys::generic_category() );
+        sys::error_code e3( e2.value(), e2.category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal against normal (inequal, value, generic)
+    {
+        sys::error_code e2( 0, sys::generic_category() );
+        sys::error_code e3( EINVAL, sys::generic_category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal against normal (inequal, value, system)
+    {
+        sys::error_code e2( 1, sys::system_category() );
+        sys::error_code e3( 2, sys::system_category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal against normal (inequal, category)
+    {
+        sys::error_code e2( 0, sys::system_category() );
+        sys::error_code e3( 0, sys::generic_category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // empty against normal
+    {
+        sys::error_code e2;
+        sys::error_code e3( e2.value(), e2.category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    // std:: wrapping against normal
+    {
+        std::error_code e1( EINVAL, std::generic_category() );
+
+        sys::error_code e2( e1 );
+        sys::error_code e3( e2.value(), e2.category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // empty against wrapping std:: empty
+    {
+        std::error_code e1;
+
+        sys::error_code e2( e1 );
+        sys::error_code e3;
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // empty against roundtrip via std
+    {
+        sys::error_code e2;
+
+        std::error_code e1( e2 );
+        sys::error_code e3( e1 );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal/generic against roundtrip via std
+    {
+        sys::error_code e2( EINVAL, boost::system::generic_category() );
+
+        std::error_code e1( e2 );
+        sys::error_code e3( e1 );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal/system against roundtrip via std
+    {
+        sys::error_code e2( 0, boost::system::system_category() );
+
+        std::error_code e1( e2 );
+        sys::error_code e3( e1 );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+#endif
+
+    return boost::report_errors();
+}