[Libguestfs] [PATCH nbdkit v2 0/3] Access export name from plugins.

[Richard W.M. Jones]

The previous incomplete patch was here:
https://www.redhat.com/archives/libguestfs/2019-September/msg00049.html
based on earlier discussion here:
https://www.redhat.com/archives/libguestfs/2019-September/msg00047.html

In v2:

 - The previous patch was incomplete.  This version completes it by
   adding tests and extending nbdkit-sh-plugin.

 - nbdkit_export_name now returns NULL for error, setting
   nbdkit_error.  The only possible error currently is if we're not
   called from a connected callback.

 - For oldstyle protocol, "" is returned.

 - Add some clarifying text to docs for can_multi_conn.

 - Use strcpy in one place instead of memcpy (but leave the other one
   alone).

As before this patch doesn't attempt to resolve any problems with our
current handling of -e, NBD_OPT_LIST, etc.

Rich.