problems which were introduced during work on WL#2787 "Add view definer/owner
to the view definition (.frm) to check privileges on used tables and stored
routines when using a VIEW."

In some cases it is better to use value from Security_context::host_or_ip
instead of value from Security_context::host since the latter can be NULL
in certain situations (When we can't resolve hostname or we have not done
this yet).