[Boost-bugs] [Boost C++ Libraries] #1952: The operation static_cast<std::string>(boost::python::extract<std::string>(...)) crashes Python. Seems to create reference counting problem.

Subject: [Boost-bugs] [Boost C++ Libraries] #1952: The operation static_cast<std::string>(boost::python::extract<std::string>(...)) crashes Python. Seems to create reference counting problem.
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-05-27 14:42:27

#1952: The operation
static_cast<std::string>(boost::python::extract<std::string>(...))  crashes
Python. Seems to create reference counting problem.
--------------------------------------------------------------------+-------
 Reporter:  Konstantin Aslanidi <konstantin.aslanidi_at_[hidden]>  |       Owner:  dave       
     Type:  Bugs                                                    |      Status:  new        
Milestone:  Boost 1.36.0                                            |   Component:  Python     
  Version:  Boost 1.35.0                                            |    Severity:  Showstopper
 Keywords:  python extract                                          |  
--------------------------------------------------------------------+-------
 I submit boost::python based python extension code that crashes Python
 interpreter when used as described below. I attach Visual Studio .NET
 project files.

 C:\KDocuments\Variance Swap Validation 2\VarSw2\Debug>python
 ActivePython 2.5.2.2 (ActiveState Software Inc.) based on
 Python 2.5.2 (r252:60911, Mar 27 2008, 17:57:18) [MSC v.1310 32 bit
 (Intel)] on
 win32
 Type "help", "copyright", "credits" or "license" for more information.
 >>> import vrsw2
 >>> p=vrsw2.VarSwapTest()
 >>> p.set(((1,2),(3,4)))
 <crash here>

 The C++ extension code:
 #include <string>
 #include <fstream>
 #include <boost/python.hpp>
 #include <boost/shared_ptr.hpp>
 using namespace boost::python;


 class VarSwapTest
 {
 private:
         class Impl
         {
         private:
                         std::ofstream theFile;
                 public:
                         Impl()
                                 : theFile("VarSwapTestEcho.txt")
                                 {}

                         void set( object& input )
                         {
                                 object o=input.attr("__str__")();
                                 extract<std::string> ex(o);
                                 if( ex.check() )
 theFile<<(static_cast<std::string>(ex()))<<std::endl;
                                 else
                                         theFile<<"failed to extract
 string"<<std::endl;
                         }
         };
 private:
         boost::shared_ptr<Impl> theImpl;
 public:
         VarSwapTest() : theImpl(new Impl()) {}
         void set( object input )
         {
                 theImpl->set(input);
         }
 };

 BOOST_PYTHON_MODULE(vrsw2)
 {
         class_<VarSwapTest>("VarSwapTest")
                 .def("set",&VarSwapTest::set)
         ;
 }

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/1952>
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