Submitted by: @mrotteveel

The FETCH RELATIVE 1 FROM cursor_name statement should be equivalent to FETCH NEXT FROM cursor_name (or FETCH cursor_name), however it skips the first row;

execute block
returns (rowval integer, rowcount integer)
as
declare c scroll cursor for (select 1 as rowval from rdb$database union all select 2 as rowval from rdb$database union all select 3 as rowval from rdb$database);
begin
open c;
-- fetch next from c;
fetch relative 1 from c;
rowval = c.rowval;
rowcount = row_count;
suspend;
end

This returns (2, 1) for (rowval, rowcount), instead of expected (1, 1). For subsequent fetches, it behaves as expected (fetching the next record), so it seems the problem is with the FETCH RELATIVE only when the cursor is newly opened. Using FETCH RELATIVE 2 FROM c will return (3,1) instead of (2,1).

It seems to behave as if the first row was already fetched, but using FETCH RELATIVE 0 FROM c will produce error "Cursor C is not positioned in a valid record".

Commits: b7b2bed f2fc97a

====== Test Details ======

Currently works OK only for 4.0.0.2369. Intermediate build 3.0.8.33416 with stamp 17-feb-2021 16:35 still issues wrong result.
Sent letter to dimitr, 17.02.2021 20:46.