SFID: 625899#
Submitted By: alexpeshkoff

Bugcheck 291 occurs when update of that same record,
that fired a trigger, done in BEFORE UPDATE trigger.

Testing environment - FB1.0, FB1.5 / Win32.

This bug appears to be FB/IB version and OS
independent, but if someone may check it with LINUX
and/or old Interbase versions, that should be useful.

This small script (just 1 table with 2 fields, 1 trigger and
4 records) always raise bugcheck 291 - cannnot find
back record version.
I have added the following debugging in jrd/exe.cpp
(modify):

after case req::req_return:
gds__log("I %p %p %p %6d %3d %6d %3d %s",
  org_rpb, org_rpb->rpb_record, org_rpb->rpb_prior,
  org_rpb->rpb_page, org_rpb->rpb_line,
  org_rpb->rpb_b_page, org_rpb->rpb_b_line,
  org_rpb->rpb_relation->rel_name);

before VIO_modify
gds__log("< ... (all the rest is the same)
after VIO_modify
gds__log("> ... (all the rest is the same)

This is the output of this debugging (a bit stripped):
OK (Server) Sun Oct 20 15:18:29 2002
I 02708CF4 02720D48 00000000 150 2 0 0 T1
I 026F083C 026F55A8 00000000 150 3 0 0 T1
I 02708464 026F2AA8 00000000 150 0 0 0 T1
I 02707CEC 026F2D40 00000000 150 3 0 0 T1
< 02707CEC 026F2D40 00000000 150 3 0 0 T1
> 02707CEC 026F2D40 026F2D40 150 3 150 4 T1
< 02708464 026F2AA8 00000000 150 0 0 0 T1
> 02708464 026F2AA8 026F2AA8 150 0 150 5 T1
I 02708514 026F2720 00000000 150 1 0 0 T1
I 02707D9C 026F1680 026F1680 150 3 150 4 T1
< 02707D9C 026F1680 026F1680 150 3 150 4 T1
> 02707D9C 026F1680 00000000 150 3 150 6 T1
< 02708514 026F2720 00000000 150 1 0 0 T1
> 02708514 026F2720 026F2720 150 1 150 4 T1
< 026F083C 026F55A8 00000000 150 3 0 0 T1
> 026F083C 026F55A8 026F55A8 150 3 150 7 T1
I 026F08EC 026F19F0 026F19F0 150 3 150 7 T1
I 02708724 026F1D70 026F1D70 150 3 150 7 T1
< 02708724 026F1D70 026F1D70 150 3 150 7 T1
> 02708724 026F1D70 00000000 150 3 150 8 T1
< 026F08EC 026F19F0 026F19F0 150 3 150 7 T1

OK (Server) Sun Oct 20 15:18:29 2002
Database: C:\INFOSYSTEM\BUG291.GDB
 internal gds software consistency check
(cannot find record back version (291))

OK (Server) Sun Oct 20 15:18:29 2002


OK (Server) Sun Oct 20 15:18:29 2002
Database: C:\INFOSYSTEM\BUG291.GDB
 internal gds software consistency check
(cannot find record back version (291))

OK (Server) Sun Oct 20 15:18:29 2002

You may see, that firebird lost that part of information
about back version of the record, that was stored in rpb.
Any ideas?