ODBC SQLSetDescRec fix

Hi,
I'm using freeTDS with sqlapi and using the odbc interface as recommended by
sqlapi to connect to a MSSQL server.

My program was crashing, so I tracked the issue back to a call made from
sqlapi to the freeTDS SQLSetDescRec method. It seems that sqlapi and freetds
disagree over the meaning of the nRecordNumber parameter, with sqlapi
starting indexing at 1 and freetds starting at 0, with the end result that
memory past the end of desc->records was being written to (and thus causing
the crash).

Looking at the MSDN ODBC reference
http://msdn.microsoft.com/en-us/library/ms714675(VS.85).aspx  it looks to me
that nRecordNumber should start indexing at 1, with an index of 0 being
reserved for the 'bookmark record', though I'm not sure what the bookmark
record is....

so I modified freeTDS to adjust the offset before accessing the
desc->records array (very simple patch attached) and this fixed my problem.

hopefully this is a real bug report / patch and is helpful to you,

regards,

Amir

PS I'm using freeTDS version 0.64, but the patch is against current CVS
which still appears to have the same problem

--
Amir Shamsuddin

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diff -ur freetds-cvs/src/odbc/odbc.c freetds-patched/src/odbc/odbc.c
--- freetds-cvs/src/odbc/odbc.c	2008-12-17 11:04:34.000000000 +0000
+++ freetds-patched/src/odbc/odbc.c	2009-02-23 14:30:09.646452900 +0000
@@ -2199,12 +2199,12 @@
 		ODBC_RETURN(desc, SQL_ERROR);
 	}
 
-	if (nRecordNumber > desc->header.sql_desc_count || nRecordNumber < 0) {
+	if (nRecordNumber > desc->header.sql_desc_count || nRecordNumber <= 0) {
 		odbc_errs_add(&desc->errs, "07009", NULL);
 		ODBC_RETURN(desc, SQL_ERROR);
 	}
 
-	drec = &desc->records[nRecordNumber];
+	drec = &desc->records[nRecordNumber - 1];
 
 	/* check for valid types and return "HY021" if not */
 	if (desc->type == DESC_IPD) {
@@ -2257,12 +2257,12 @@
 		ODBC_RETURN(desc, SQL_ERROR);
 	}
 
-	if (RecordNumber > desc->header.sql_desc_count || RecordNumber < 0) {
+	if (RecordNumber > desc->header.sql_desc_count || RecordNumber <= 0) {
 		odbc_errs_add(&desc->errs, "07009", NULL);
 		ODBC_RETURN(desc, SQL_ERROR);
 	}
 
-	drec = &desc->records[RecordNumber];
+	drec = &desc->records[RecordNumber - 1];
 
 	if ((rc = odbc_set_string(Name, BufferLength, StringLength, tds_dstr_cstr(&drec->sql_desc_name), -1)) != SQL_SUCCESS)
 		odbc_errs_add(&desc->errs, "01004", NULL);