Re: [Libguestfs] [libnbd PATCH 2/2] api: Add STRICT_BOUNDS to nbd_set_strict_mode

The NBD protocol states that a 0-length request is undefined; we were inconsistent in that we let it through for read, write, and cache, but blocked it for trim, zero, and block_status. The NBD protocol also has documented rules on handling access beyond EOF, but we are currently wasting traffic to the server when we can give the same answer ourselves. Exposing this as a strictness knob gives the user finer-grained control over what behavior they want. --- Question: should this be split into two flags, one to prevent 0-length requests, and the other to prevent out-of-bounds requests?