thread_specific_ptr lacks support for NULL cleanup function

[Bryan Green <bryan.d.green@…>]

Passing a null pointer as the cleanup_function argument to the thread_specific_ptr constructor leads to a null dereference and a program crash.

Use of a null cleanup function is well defined in the pthread API: it means that no cleanup is to be performed. Boost::Thread currently lacks this mode, requiring the programmer to define a specialized empty function any time a thread_specific_ptr is created where no cleanup is desired.

I'm filing this as a bug, since it represents a common practice, well supported and documented in the pthread API, which in boost leads to a program crash.

I'm attaching a patch representing a potential implementation of NULL-cleanup-function support.

[Bryan Green <bryan.d.green@…>]

patch to apply at ROOT/boost/thread for NULL cleanup_function support

[Anthony Williams]

Fixed on trunk