If a call to select.select() was interrupted by a signal and the select syscall set an errno of EINTR, then under PEP 475 the select call should be re-executed.

If, however, there is a signal handler which takes enough time that the select's timeout expires, select() is not retried, and the rlist is returned as-is (with fds in it which are not ready for reading).

Under this condition, either select() should be re-run with a timeout of 0, or the fd lists should be emptied before returning.

Example code which reproduces the problem attached.