[Libguestfs] [PATCH libnbd 0/5] interop: Check that LIBNBD_TLS_ALLOW works against nbdkit.

I was a little surprised to find that LIBNBD_TLS_ALLOW worked out of the box, so I had to examine the logs whereupon I saw the magic message ... libnbd: debug: nbd1: nbd_connect_command: server refused TLS (policy), continuing with unencrypted connection I don't believe this path has ever been tested before. It's possible the tests could be improved if they actually checked for this message, but the patches as posted try to use regular APIs. Rich.