Access Violation upnp::delete_port_mapping

[pavel-pimenov]

libtorrent version (or branch): master
platform/architecture: Win 7 sp1 x86
compiler and compiler version: VC++2015 update 3

Dumps from anonymous users:
https://drdump.com/Problem.aspx?ProblemID=238693

flylinkdc!strnlen+0xdc
flylinkdc!__crt_stdio_output::output_processor<char,__crt_stdio_output::string_output_adapter,__crt_stdio_output::format_validation_base<char,__crt_stdio_output::string_output_adapter > >::type_case_s+0x68
flylinkdc!__crt_stdio_output::output_processor<char,__crt_stdio_output::string_output_adapter,__crt_stdio_output::standard_base<char,__crt_stdio_output::string_output_adapter > >::state_case_type+0x4d
flylinkdc!__crt_stdio_output::output_processor<char,__crt_stdio_output::string_output_adapter,__crt_stdio_output::standard_base<char,__crt_stdio_output::string_output_adapter > >::process+0xc5
flylinkdc!__acrt_lock_stream_and_call<<lambda_4f2c1eaeead2a5fc776db5b62ea0fb9b> >+0x404
flylinkdc!__stdio_common_vsprintf+0x1f
flylinkdc!vsnprintf+0x23
flylinkdc!snprintf+0x16
flylinkdc!libtorrent::upnp::delete_port_mapping+0x97
flylinkdc!std::_Func_impl<std::_Binder<std::_Unforced,void (__thiscall libtorrent::upnp::)(libtorrent::upnp::rootdevice &,int),std::shared_ptrlibtorrent::upnp,std::reference_wrapperlibtorrent::upnp::rootdevice,int &>,std::allocator,void,libtorrent::http_connection &>::_Do_call+0x13
flylinkdc!libtorrent::http_connection::on_connect+0x84
flylinkdc!std::invoke<void (__thiscall libtorrent::http_connection::&)(boost::system::error_code const &),std::shared_ptrlibtorrent::http_connection &,boost::system::error_code const &>+0x16
kernelbase!GetQueuedCompletionStatus+0x29
flylinkdc!boost::asio::detail::win_iocp_io_service::do_one+0x1cd
flylinkdc!boost::asio::detail::win_iocp_io_service::run+0xc8
flylinkdc!boost::asio::io_service::run+0x2a
flylinkdc!std::_Pad::_Call_func+0x50
flylinkdc!wcsftime+0xf5
kernel32!BaseThreadInitThunk+0xe
ntdll!__RtlUserThreadStart+0x70
ntdll!_RtlUserThreadStart+0x1b