Re: psqlodbc.dll crash - Mailing list pgsql-odbc

used = -5 means SQL_DEFAULT_PARAM. I changed the driver
to ignore it. Please try the lastest snapshot dll at
  http://www.geocities.jp/inocchichichi/psqlodbc/.

Thanks for your report.

Hiroshi Inoue
    http://www.geocities.jp/inocchichichi/psqlodbc/


Tambet Matiisen wrote:
>
> ----- Original Message -----
> From: "Tambet Matiisen" <t.matiisen@aprote.ee>
> To: <pgsql-odbc@postgresql.org>
> Sent: Friday, January 31, 2003 11:39 AM
> Subject: [ODBC] psqlodbc.dll crash
>
> > Psqlodbc.dll crashes my application occasionally with following error:
> > Unhandled exception in VB6.EXE (PSQLODBC.DLL): 0xC0000005: Access
> Violation.
> >
> > The error occurs when I have 3 opened ADO recordsets, I requery all of
> them
> > and then open one more recordset. And I have to do this 5-6 times to get
> > this error. All recordsets are static and client-side. If someone could
> send
> > me debug version of the dll, I could give more information.
> >
> >   Tambet
> >
> >
>
> I resolved the issue, parameters of one of the recordsets did not have
> default values. But it still indicates, that error handling in driver could
> be improved. The query executed was:
>
> conn=82461600, query='SELECT kood as "Kood", nimetus as "Nimetus",
> prioriteet as "Prioriteet", mat_id, yhik, erikaal, viimane_hind,
> broneeritud, olemas, tellitud, (mat.tellitud + mat.olemas - mat.broneeritud)
> AS saldo FROM materjalid mat WHERE kood LIKE '\x90' AND lower(nimetus) LIKE
> lower('')'
>
> Note the abnormal characters in where condition. The crash occurred in
> convert_special_chars() in convert.c:
>
> convert_special_chars(const char * 0x045fe000, char * 0x00000000, int -5,
> int 1, int 0) line 3381 + 36 bytes
> ResolveOneParam(_QueryBuild * 0x0012deec) line 2634 + 35 bytes
> inner_process_tokens(_QueryParse * 0x0012df30, _QueryBuild * 0x0012deec)
> line 2190 + 9 bytes
> copy_statement_with_parameters(StatementClass_ * 0x04ffe3c8, int 0) line
> 1921 + 19 bytes
> Exec_with_parameters_resolved(StatementClass_ * 0x04ffe3c8, int *
> 0x0012e0d4) line 222 + 13 bytes
> PGAPI_Execute(void * 0x04ffe3c8) line 596 + 13 bytes
> SQLExecute(void * 0x04ffe3c8) line 279 + 9 bytes
> ODBC32! 1f7cd8eb()
> MSDASQL! 1f6c78cb()
> MSDASQL! 1f69c94b()
> MSDASQL! 1f69c688()
> 0012e34c()
>
> The error was on line 3381:
>
> for (i = 0; i < max && si[i]; i++)
>
> Probably because si[i] was out of bounds. But this should have been
> eliminated by i < max condition. Max is calculated based on parameter 'used'
> of the same function:
>
> if (used == SQL_NTS)
>     max = strlen(si);
> else
>     max = used;
>
> As you can see from stack trace earlier, used = -5. But SQL_NTS is defined
> as -1. This means, that max gets value -5. But as max is of unsigned type
> (size_t), the actual value is 4294967291 instead. This allows above
> mentioned cycle to go out of bounds.
>
> I don't have the knowledge and time to fix this error by myself. But it
> would be nice if someone could have a look.
>
>     Tambet
>
> PS. Source distribution of psqlodbc.dll 7.2.5 was not complete, setup.c and
> some other files were missing. I used the CVS snapshot, but still couldn't
> compile the non-multibyte version. Multibyte version was OK.
> PPS. It took me some time to find out how to access CVS on
> gborg.postgresql.org. I could not find any official documentation on Gborg
> website. Finally I found some instructions in list archives.