Re: Don't use the deprecated and insecure PQcancel in our frontend tools anymore

On Sun Dec 14, 2025 at 3:40 PM CET, Jelte Fennema-Nio wrote:
> A bunch of frontend tools, including psql, still used PQcancel to send
> cancel requests to the server. That function is insecure, because it
> does not use encryption to send the cancel request. This starts using
> the new cancellation APIs (introduced in 61461a300) for all these
> frontend tools.

Small update. Split up the fe_utils and pg_dump changes into separate
commits, to make patches easier to review. Also use non-blocking writes
to the self-pipe from the signal handler to avoid potential deadlocks
(extremely unlikely for such blocks to occur, but better safe than sorry).