From 8d6517484cd542cc4c634a8d533557b843f37a47 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Fri, 22 Nov 2002 13:49:54 +0000
Subject: [PATCH] Stricter tests; associated bug fixes. ;-)

[SVN r16369]
---
 include/boost/shared_ptr.hpp | 6 ++++--
 include/boost/weak_ptr.hpp   | 7 ++++++-
 shared_ptr_test.cpp          | 9 ++++++++-
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/include/boost/shared_ptr.hpp b/include/boost/shared_ptr.hpp
index cbd9fd3..5a9a44b 100644
--- a/include/boost/shared_ptr.hpp
+++ b/include/boost/shared_ptr.hpp
@@ -140,8 +140,10 @@ public:
 #endif
 
     template<class Y>
-    explicit shared_ptr(weak_ptr<Y> const & r): px(r.px), pn(r.pn) // may throw
+    explicit shared_ptr(weak_ptr<Y> const & r): pn(r.pn) // may throw
     {
+        // it is now safe to copy r.px, as pn(r.pn) did not throw
+        px = r.px;
     }
 
     template<class Y>
@@ -166,7 +168,7 @@ public:
     template<class Y>
     shared_ptr(shared_ptr<Y> const & r, detail::polymorphic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
     {
-        if (px == 0)
+        if(px == 0)
         {
             boost::throw_exception(std::bad_cast());
         }
diff --git a/include/boost/weak_ptr.hpp b/include/boost/weak_ptr.hpp
index a4154ea..d08fa5d 100644
--- a/include/boost/weak_ptr.hpp
+++ b/include/boost/weak_ptr.hpp
@@ -16,6 +16,8 @@
 
 #include <boost/shared_ptr.hpp>
 
+#include <cstring> // for std::memcpy
+
 #ifdef BOOST_MSVC  // moved here to work around VC++ compiler crash
 # pragma warning(push)
 # pragma warning(disable:4284) // odd return type for operator->
@@ -42,8 +44,11 @@ public:
 //  generated copy constructor, assignment, destructor are fine
 
     template<class Y>
-    weak_ptr(weak_ptr<Y> const & r): px(r.px), pn(r.pn) // never throws
+    weak_ptr(weak_ptr<Y> const & r): pn(r.pn) // never throws
     {
+        // r.px may be an invalid pointer value
+        using namespace std;
+        memcpy(&this->px, &r.px, sizeof(r.px));
     }
 
     template<class Y>
diff --git a/shared_ptr_test.cpp b/shared_ptr_test.cpp
index 87553d5..cbaaeed 100644
--- a/shared_ptr_test.cpp
+++ b/shared_ptr_test.cpp
@@ -99,7 +99,9 @@ private:
 
 long X::instances = 0;
 
-struct Y: public A, public X
+// virtual inheritance stresses the implementation
+
+struct Y: public A, public virtual X
 {
     static long instances;
 
@@ -771,6 +773,11 @@ void weak_ptr_constructor()
     catch(boost::bad_weak_ptr)
     {
     }
+
+    {
+        boost::weak_ptr<Y> wp2(wp);
+        boost::weak_ptr<X> wp3(wp);
+    }
 }
 
 void auto_ptr_constructor()