Wouldn't retrying on EINTR cause havoc when you try to interrupt a process?

That is: what would happen with the proposed patch when a python script does a read that takes a very long time and the user tries to interrupt the script (by using Ctrl+C to send a SIGTERM)?

If I my understanding of is correct the patch will ensure that the process does not get interupted because the default SIGTERM handler just sets a flag that's periodicly checked in the python interpreter loop.  With the proposed patch python would not get around to checking that flag until the I/O operation is finished.