FreeTDS Development Group

[Brian Bruns <camber AT umcc.ais.org>]

Kevin,

Here is the dropped byte problem that I found, hopefully it is the same
one you are seeing.  This is in reference to the submitted patch. And I do
believe it made it into CVS.

Brian

 ---------- Forwarded message ----------
Date: Wed, 30 Dec 1998 20:57:57 -0500 (EST)
From: Brian Bruns <camber AT umcc.ais.org>
To: Gregg Jensen <greggj AT savvis.net>
Cc: tetherow AT nol.nol.org
Subject: Re: [Fwd: tds_unget_byte]

Hi Gregg, I found the problem.  

It's in read.c; I noted it down aways in this message.  This stuff is
working on linux, so I will check it in.  I compiled SQSH and threw
every query I could think of at it.

Cheers,

Brian

On Wed, 30 Dec 1998, Gregg Jensen wrote:

> >   read.c      Documented most of the functions and my changes.
> >               tds_get_smallint uses the if def setup that has passed
> >               around in various formats.
> >               tds_get_n does direct copies from in_buf to dest
> >               (unless dest==NULL) and handles breaks across packet
> >               boundaries.
> >               tds_read_packet now handles variable packet sizes and
> >               insures that all bytes are read for the packet (actually
> >               had a problem where MSSQL said it was sending a 512 byte
> >               packet and it sent a 412 followed by the next 100 bytes
> >               across the stream, ie they didn't write all 512 at once)
> >
[snip]
> > diff -c -b -r freetds/src/tds/read.c freetds.local/src/tds/read.c
> > *** freetds/src/tds/read.c      Fri Nov 20 22:30:55 1998
> > --- freetds.local/src/tds/read.c        Tue Dec 22 15:59:29 1998
> > ***************
[old code snipped to keep it short]
> > ! /*
> > ! ** Get N bytes from the buffer and return them in the already allocated 
> > space
> > ! ** given to us.  We ASSUME that the person calling this function has 
> > done the
> > ! ** bounds checking for us since they know how many bytes they want here.
> > ! ** dest of NULL means we just want to eat the bytes.   
> > (tetherow AT nol.org)
> > ! 
> > *******************************************************************************/
> > ! char *tds_get_n(TDSSOCKET *tds, void *dest, int need) {
> > !       int pos, have;
> >
> > !       pos = 0;
> >
> > !       have=(tds->in_len-tds->in_pos);
> > !       while (need>have) {
> > !               /* We need more than is in the buffer, copy what is there 
> > */
> > !               if (dest!=NULL) {
> > !                       memcpy(dest+pos, tds->in_buf+tds->in_pos, have);
> > !               }
> > !               pos+=have;
> > !               need-=have;
> > !               tds_read_packet(tds);
> > !               have=tds->in_len;
> > !       }
> > !       if (need>0) {
> > !               /* get the remainder if there is any */
> > !               if (dest!=NULL) {
> > !                       memcpy(dest, tds->in_buf+tds->in_pos, need);

                       /* should be */
                       memcpy(dest+pos, tds->in_buf+tds->in_pos, need);

> > !               }
> > !               tds->in_pos+=need;
> > !       }
> > !       return(dest);
> >   }