From f5dc3715bc3d0c15985846be75e4aa69623cd318 Mon Sep 17 00:00:00 2001
From: Emil Dotchevski <emil@revergestudios.com>
Date: Sun, 10 Apr 2011 02:13:12 +0000
Subject: [PATCH] merged changes from trunk: better
 boost::diagnostic_information

[SVN r71158]
---
 .../exception/diagnostic_information.hpp      | 58 ++++++++++++-------
 include/boost/exception/info.hpp              |  1 -
 test/diagnostic_information_test.cpp          | 11 ++++
 3 files changed, 48 insertions(+), 22 deletions(-)

diff --git a/include/boost/exception/diagnostic_information.hpp b/include/boost/exception/diagnostic_information.hpp
index 7cbb355..ef89d73 100644
--- a/include/boost/exception/diagnostic_information.hpp
+++ b/include/boost/exception/diagnostic_information.hpp
@@ -14,6 +14,7 @@
 
 #include <boost/config.hpp>
 #include <boost/exception/get_error_info.hpp>
+#include <boost/exception/info.hpp>
 #include <boost/utility/enable_if.hpp>
 #ifndef BOOST_NO_RTTI
 #include <boost/units/detail/utility.hpp>
@@ -85,19 +86,23 @@ boost
         char const *
         get_diagnostic_information( exception const & x, char const * header )
             {
-            if( error_info_container * c=x.data_.get() )
 #ifndef BOOST_NO_EXCEPTIONS
-                try
-                    {
+            try
+                {
 #endif
-                    return c->diagnostic_information(header);
+                error_info_container * c=x.data_.get();
+                if( !c )
+                    x.data_.adopt(c=new exception_detail::error_info_container_impl);
+                char const * di=c->diagnostic_information(header);
+                BOOST_ASSERT(di!=0);
+                return di;
 #ifndef BOOST_NO_EXCEPTIONS
-                    }
-                catch(...)
-                    {
-                    }
+                }
+            catch(...)
+                {
+                return 0;
+                }
 #endif
-            return 0;
             }
 
         inline
@@ -122,18 +127,26 @@ boost
             std::ostringstream tmp;
             if( be )
                 {
-                if( char const * const * f=get_error_info<throw_file>(*be) )
-                    {
-                    tmp << *f;
-                    if( int const * l=get_error_info<throw_line>(*be) )
-                        tmp << '(' << *l << "): ";
-                    }
-                tmp << "Throw in function ";
-                if( char const * const * fn=get_error_info<throw_function>(*be) )
-                    tmp << *fn;
+                char const * const * f=get_error_info<throw_file>(*be);
+                int const * l=get_error_info<throw_line>(*be);
+                char const * const * fn=get_error_info<throw_function>(*be);
+                if( !f && !l && !fn )
+                    tmp << "Throw location unknown (consider using BOOST_THROW_EXCEPTION)\n";
                 else
-                    tmp << "(unknown)";
-                tmp << '\n';
+                    {
+                    if( f )
+                        {
+                        tmp << *f;
+                        if( int const * l=get_error_info<throw_line>(*be) )
+                            tmp << '(' << *l << "): ";
+                        }
+                    tmp << "Throw in function ";
+                    if( char const * const * fn=get_error_info<throw_function>(*be) )
+                        tmp << *fn;
+                    else
+                        tmp << "(unknown)";
+                    tmp << '\n';
+                    }
                 }
 #ifndef BOOST_NO_RTTI
             tmp << std::string("Dynamic exception type: ") <<
@@ -166,7 +179,10 @@ boost
             {
 #endif
             (void) exception_detail::diagnostic_information_impl(&e,0,false);
-            return exception_detail::get_diagnostic_information(e,0);
+            if( char const * di=exception_detail::get_diagnostic_information(e,0) )
+                return di;
+            else
+                return "Failed to produce boost::diagnostic_information_what()";
 #ifndef BOOST_NO_EXCEPTIONS
             }
         catch(
diff --git a/include/boost/exception/info.hpp b/include/boost/exception/info.hpp
index c918dbd..5530746 100644
--- a/include/boost/exception/info.hpp
+++ b/include/boost/exception/info.hpp
@@ -109,7 +109,6 @@ boost
                 {
                 if( header )
                     {
-                    BOOST_ASSERT(*header!=0);
                     std::ostringstream tmp;
                     tmp << header;
                     for( error_info_map::const_iterator i=info_.begin(),end=info_.end(); i!=end; ++i )
diff --git a/test/diagnostic_information_test.cpp b/test/diagnostic_information_test.cpp
index 8ced6e3..85e8a67 100644
--- a/test/diagnostic_information_test.cpp
+++ b/test/diagnostic_information_test.cpp
@@ -200,6 +200,17 @@ main()
         std::string di=current_exception_diagnostic_information();
         test3(di);
         }
+    try
+        {
+        throw error4();
+        }
+    catch(
+    error4 & x )
+        {
+        std::string di1=boost::diagnostic_information(x);
+        std::string wh1=x.what();
+        BOOST_TEST(wh1==di1);
+        }
     try
         {
         error4 x; x << tagged_int1(42) << tagged_int2(42);