From 472b18881b54a1fb84abd1fcf0485fec58d6deaa Mon Sep 17 00:00:00 2001
From: "Ralf W. Grosse-Kunstleve" <rwgk@yahoo.com>
Date: Tue, 23 Dec 2008 07:55:33 +0000
Subject: [PATCH] Boost.Python enable_shared_from_this patches by Nicolas
 Lelong and Chad Austin:  
 http://mail.python.org/pipermail/cplusplus-sig/2008-December/014103.html  
 http://mail.python.org/pipermail/cplusplus-sig/2008-February/013003.html

[SVN r50368]
---
 .../converter/shared_ptr_from_python.hpp      | 10 ++--
 test/Jamfile.v2                               |  1 +
 test/enable_shared_from_this.cpp              | 48 +++++++++++++++++++
 test/enable_shared_from_this.py               | 26 ++++++++++
 4 files changed, 82 insertions(+), 3 deletions(-)
 create mode 100644 test/enable_shared_from_this.cpp
 create mode 100755 test/enable_shared_from_this.py

diff --git a/include/boost/python/converter/shared_ptr_from_python.hpp b/include/boost/python/converter/shared_ptr_from_python.hpp
index 6b49c469..c0910776 100644
--- a/include/boost/python/converter/shared_ptr_from_python.hpp
+++ b/include/boost/python/converter/shared_ptr_from_python.hpp
@@ -45,10 +45,14 @@ struct shared_ptr_from_python
         if (data->convertible == source)
             new (storage) shared_ptr<T>();
         else
+        {
+            boost::shared_ptr<void> hold_convertible_ref_count(
+              (void*)0, shared_ptr_deleter(handle<>(borrowed(source))) );
+            // use aliasing constructor
             new (storage) shared_ptr<T>(
-                static_cast<T*>(data->convertible),
-                shared_ptr_deleter(handle<>(borrowed(source)))
-                );
+                hold_convertible_ref_count,
+                static_cast<T*>(data->convertible));
+        }
         
         data->convertible = storage;
     }
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 4e1479b4..5f66be63 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -75,6 +75,7 @@ bpl-test crossmod_exception
 [ bpl-test return_arg ]
 [ bpl-test staticmethod ]
 [ bpl-test shared_ptr ]
+[ bpl-test enable_shared_from_this ]
 [ bpl-test andreas_beyer ]
 [ bpl-test polymorphism ]
 [ bpl-test polymorphism2 ]
diff --git a/test/enable_shared_from_this.cpp b/test/enable_shared_from_this.cpp
new file mode 100644
index 00000000..c246284a
--- /dev/null
+++ b/test/enable_shared_from_this.cpp
@@ -0,0 +1,48 @@
+// Copyright David Abrahams 2002.
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/python/module.hpp>
+#include <boost/python/class.hpp>
+#include <boost/python/call_method.hpp>
+#include <boost/python/extract.hpp>
+#include <boost/python/def.hpp>
+#include <boost/enable_shared_from_this.hpp>
+#include <boost/shared_ptr.hpp>
+#include "test_class.hpp"
+
+#include <memory>
+
+using namespace boost::python;
+using boost::shared_ptr;
+
+class Test;
+typedef shared_ptr<Test> TestPtr;
+
+class Test : public boost::enable_shared_from_this<Test> {
+public:
+    static TestPtr construct() {
+        return TestPtr(new Test);
+    }
+
+    void act() {
+        TestPtr kungFuDeathGrip(shared_from_this());
+    }
+
+    void take(TestPtr t) {
+    }
+};
+
+BOOST_PYTHON_MODULE(enable_shared_from_this_ext)
+{
+    class_<Test, TestPtr, boost::noncopyable>("Test")
+        .def("construct", &Test::construct).staticmethod("construct")
+        .def("act", &Test::act)
+        .def("take", &Test::take)
+        ;
+}
+
+#include "module_tail.cpp"
+
+
diff --git a/test/enable_shared_from_this.py b/test/enable_shared_from_this.py
new file mode 100755
index 00000000..cca46ec8
--- /dev/null
+++ b/test/enable_shared_from_this.py
@@ -0,0 +1,26 @@
+# Copyright David Abrahams 2004. Distributed under the Boost
+# Software License, Version 1.0. (See accompanying
+# file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+'''
+>>> from enable_shared_from_this_ext import *
+
+>>> x = Test.construct()
+>>> x.take(x)
+>>> x.act()
+'''
+
+def run(args = None):
+    import sys
+    import doctest
+
+    if args is not None:
+        sys.argv = args
+    return doctest.testmod(sys.modules.get(__name__))
+
+if __name__ == '__main__':
+    print "running..."
+    import sys
+    status = run()[0]
+    if (status == 0): print "Done."
+    sys.exit(status)
+