Submitted by: @pavel-zotov

C:\1INSTALL\FIREBIRD\FB_2_5>.\bin\isql TTT.FDB
Database: TTT.FDB
SQL> recreate table t(id int, f01 int); commit;
SQL> insert into t values(1, 100);
SQL> insert into t values(2, 200);
SQL> insert into t values(3, 999);
SQL> update t set f01=-f01 order by id desc rows 1;
SQL> -- NOW PRESS CTRL-C ---

C:\1INSTALL\FIREBIRD\FB_2_5>.\bin\isql TTT.FDB
Database: TTT.FDB
SQL> select * from t;

      ID          F01

============ ============
1 100
2 200
3 -999

PS. In trace log there will be following text for last update statement and pressing Ctrl-C just after update:
< ... skipped ...>
2011-11-16T18:30:40.0460 (1664:0212DEE0) EXECUTE_STATEMENT_FINISH
C:\1INSTALL\FIREBIRD\FB_2_5\TTT.FDB (ATT_5, SYSDBA:NONE, NONE, XNET:TLPRG)
C:\1INSTALL\FIREBIRD\FB_2_5\bin\isql.exe:1668
(TRA_24, CONCURRENCY | WAIT | READ_WRITE)

Statement 117:
-------------------------------------------------------------------------------
update t set f01=-f01 order by id desc rows 1
0 records fetched
0 ms, 16 fetch(es), 1 mark(s)

Table Natural Index Update Insert Delete Backout Purge Expunge
***************************************************************************************************************
T 3 1

2011-11-16T18:30:46.6870 (1664:0212DEE0) COMMIT_TRANSACTION
C:\1INSTALL\FIREBIRD\FB_2_5\TTT.FDB (ATT_5, SYSDBA:NONE, NONE, XNET:TLPRG)
C:\1INSTALL\FIREBIRD\FB_2_5\bin\isql.exe:1668
(TRA_25, READ_COMMITTED | NO_REC_VERSION | WAIT | READ_WRITE)
25 ms, 1 read(s), 11 write(s), 1 fetch(es), 1 mark(s)

2011-11-16T18:30:46.7180 (1664:0212DEE0) COMMIT_TRANSACTION
C:\1INSTALL\FIREBIRD\FB_2_5\TTT.FDB (ATT_5, SYSDBA:NONE, NONE, XNET:TLPRG)
C:\1INSTALL\FIREBIRD\FB_2_5\bin\isql.exe:1668
(TRA_24, CONCURRENCY | WAIT | READ_WRITE)
24 ms, 1 read(s), 1 write(s), 1 fetch(es), 1 mark(s)

2011-11-16T18:30:46.7180 (1664:0212DEE0) DETACH_DATABASE
C:\1INSTALL\FIREBIRD\FB_2_5\TTT.FDB (ATT_5, SYSDBA:NONE, NONE, XNET:TLPRG)
C:\1INSTALL\FIREBIRD\FB_2_5\bin\isql.exe:1668

2011-11-16T18:30:46.7180 (1664:0212DEE0) TRACE_FINI
SESSION_1 Firebird Audit