Ticket #1714: enable_shared_from_this.patch

enable_shared_from_this.hpp

@@ -93 +93 @@
     template<typename U>
     void _internal_accept_owner(shared_ptr<U> &owner) const
     {
-        init_internal_shared_once();
-        get_deleter<detail::sp_deleter_wrapper>(_internal_shared_this)->set_deleter(owner);
-        owner.reset( _internal_shared_this, owner.get() );
-        _internal_shared_this.reset();
-        _owned = true;
+        if (_owned == false)
+        {
+            init_internal_shared_once();
+            get_deleter<detail::sp_deleter_wrapper>(_internal_shared_this)->set_deleter(owner);
+            owner.reset( _internal_shared_this, owner.get() );
+            _internal_shared_this.reset();
+            _owned = true;
+        }
     }
 };