Check for valid columns in adodb postgres64 driver MetaIndexes fn (bug #796102)
Indexes on functions of columns have a 0 in the indkey column of
pg_catalog.pg_index, which doesn't refer to a column.
Don't return any columns for the index, rather than returning an empty
column name.
Change-Id: I1464b8a9fda8bd137dcabf1145da289ccf32c500
Signed-off-by:
Richard Mansfield <richard.mansfield@catalyst.net.nz>