FreeTDS Development Group

[L J Bayuk <lbayuk AT mindspring.com>]

I just got started with FreeTDS, and first of all I want to say thanks to
all the developers and other contributors. I'm using it with PHP-4.2.1 on
Linux to connect to a Sybase ASA 6 server on Novell. It really works
remarkably well.

Now for my problem. When I select from a TEXT field, the last character of
the value is lost. (CHAR and VARCHAR are OK).  This only happens when
using a recent FreeTDS "current" CVS snapshot, not when using FreeTDS-0.53.
It works fine in 0.53.

I think the problem is an off-by-1 error here in src/tds/convert.c in the
function tds_convert_text():
         cplen = srclen > destlen ? destlen : srclen;
         memcpy(dest, src, cplen);
*        dest[cplen-1] = '\0';
         return strlen(dest);

I think that (*) line should be: dest[cplen] = '\0';
(that's how it was at 0.53) but it seems to me this could overflow the dest
buffer.  I browsed the CVS on SourceForge and found that this was changed
in rev 1.13 of that file on May 25, 2002 by Victor K. but it isn't clear
why. I would like to propose the patch below. It changes it back, and
includes another change to prevent dest buffer overflow, and a third change
in how to get the return value. These make sense to me, and seem to work,
but I'm new with this so dissenting opinions would be welcome...

*** convert.c.bak       Tue Jun 25 21:44:27 2002
--- convert.c   Sat Jul  6 10:41:43 2002
***************
*** 122,131 ****
     switch(desttype) {
        case SYBTEXT:
        case SYBCHAR:
!        cplen = srclen > destlen ? destlen : srclen;
           memcpy(dest, src, cplen);
!          dest[cplen-1] = '\0';
!          return strlen(dest);
        case SYBBINARY:
         cplen = srclen > destlen ? destlen : srclen;
           memcpy(dest, src, cplen);
--- 122,131 ----
     switch(desttype) {
        case SYBTEXT:
        case SYBCHAR:
!        cplen = srclen >= destlen ? destlen-1 : srclen;
           memcpy(dest, src, cplen);
!          dest[cplen] = '\0';
!          return cplen;
        case SYBBINARY:
         cplen = srclen > destlen ? destlen : srclen;
           memcpy(dest, src, cplen);