Bug #16224 Calling SQLGetDiagField with RecNumber 0,DiagIdentifier NOT 0 returns SQL_ERROR

Description:
Calling SQLGetDiagField with RecNumber 0,DiagIdentifier NOT 0 returns SQL_ERROR.

SQLGetDiagField returns SQL_ERROR when RecNumber is 0 and a valid DiagIdentifer is specified.

The Documetation I am using says:
"If the DiagIdentifier argument indicates any field of the diagnostics header, RecNumber is ignored."

Specifying RecNumber to 1 would solve the problem as a work around.

Other info:
platform: Aix 64 5.2
odbc manager: iodbc

How to repeat:
call SQLGetDiagField with RecNumber 0 and  set DiagIdentifier to any diagnositcs header field. 

Suggested fix:
Problem is in function SQLGetDiagField() in driver/error.c

About Line 495

Existing code:
if (RecNumber == 0 && DiagIdentifier > 0 )
   DBUG_RETURN_STATUS(SQL_ERROR)

what the programmer Intended?
  if (RecNumber == 0 && DiagIdentifier == 0 )
   DBUG_RETURN_STATUS(SQL_ERROR)

Changing it to this solves the problem. 
SQLGetDiagField then works with RecNumber as 0.

Sorry...I was not able to reproduce the bug. Could you please create and attach some test case ?

a Sample functions demonstrating this problem.

/* call this method to get the number of status records that are available for the specified handle.*/
/* 
int CheckError(SQLHANDLE handle){

SQLINTEGER diagnum=-1;
int htype=SQL_HANDLE_ENV;

/* this call will always return SQL_ERROR even though its a valid thing to do*/
SQLGetDiagField((SQLSMALLINT)htype,handle,
0,SQL_DIAG_NUMBER,&diagnum,SQL_IS_INTEGER,NULL);

return(diagnum);
}

test case

Attachment: bug16224.c (text/plain), 818 bytes.

Thank you for the report.

Verified using attached test case as described on Windows XP SP2 и Solaris 10.

patch + test

Attachment: bug16224.diff (application/octet-stream, text), 1.26 KiB.

A more concise test (no need to alloc your own handles):

DECLARE_TEST(t_bug16624)
{
  SQLINTEGER diagcnt;

  expect_sql(hstmt, "This is an invalid Query! (odbc test)", SQL_ERROR);

  ok_stmt(hstmt, SQLGetDiagField(SQL_HANDLE_STMT, hstmt, 0,
                                 SQL_DIAG_NUMBER, &diagcnt,
                                 SQL_IS_INTEGER, NULL));
  is_num(diagcnt, 1);

  return OK;
}

the test needs a header, too:

/**
 Bug #16224: Calling SQLGetDiagField with RecNumber 0,DiagIdentifier NOT 0 returns SQL_ERROR
*/

Noted in 3.51.17 changelog.

Calling SQLGetDiagField with RecNumber 0, DiagIdentifier NOT 0 
returned SQL_ERROR, preventing access to diagnostic header fields.