Re: Old dblib.c bug still there

Well, I use defncopy all the time. :)  Glad we worked through this.
Should I mail this to Freddy directly or is attaching it here (as I've
done) good enough?

(Sorry if this is a repeat message - I didn't see the message I sent
yesterday show up in the archive)


On Wed, Jun 15, 2016 at 3:37 AM, Thompson, William
<[email protected]> wrote:
> Hi.
>
> Glad you found a solution!
> From looking at the code, I can see why that would be just what was needed!
> The STRINGBIND is basically saying "don't strip any trailing blanks off the returned string"
> Passing 0 as the size of the destination field is basically telling dbbind
> "don't worry, I've got enough space to take whatever you're giving me, just give me what you've got"
> So it should the give you the stored procedure text as is.
>
> The only worry in programming terms is that 16000 bytes won't be enough to hold what sql server gives us,
> But think that highly unlikely, given we know what we're selecting...
>
> My guess would be that the users of defncopy could be counted on a couple of hands.
> The stripping off blanks behaviour would mess up many stored procedures where a syntactically significant blank
> fell at the end of one of the syscomments rows, e.g.
> row 1: "....SELECT * FROM "
> row 2: "MYTABLE WHERE....."
>
> so your fix is an improvement I have no doubt!
> Make the change, and give it to Freddy as a patch.
>
> If this would then be your first contribution to the project, welcome!
>
> Bill
>
>
> -----Original Message-----
> From: FreeTDS [mailto:[email protected]] On Behalf Of Nem W Schlecht
> Sent: 14 June 2016 16:59
> To: FreeTDS Development Group
> Subject: Re: [freetds] Old dblib.c bug still there
>
> On Tue, Jun 14, 2016 at 7:43 AM, Thompson, William <[email protected]
>> wrote:
>
>> I Agree with Freddy - if you want to make a change to test it out, I'd
>> make the change to defncopy.c Try changing that NTBSTRINGBIND to plain
>> old STRINGBIND, and see how that affects the behaviour.
>> It looks to me like it should stop the trailing blanks from being
>> stripped off
>>
>>
>>
> Gave this a shot.  In my test stored procedure, it now adds around 12,000 extra spaces. Not quite what I was hoping for.  :)  Looks like it wants to pad it out to 16,000 chars.
>
> I think it would work correctly if limited_dest_space weren't set in dblib.c copy_data_to_host_var().
>
> Yes, I changed line 577 of defncopy.c from:
>
> erc = dbbind(dbproc, ctext, NTBSTRINGBIND, sizeof(sql_text), (BYTE *) sql_text);
>
> to:
>
> erc = dbbind(dbproc, ctext, STRINGBIND, 0, (BYTE *) sql_text);
>
>
> And now defncopy is working correctly on my test stored procedure.  Is this going to mess anything else up, though?
>
>
>
>
>>
>> -----Original Message-----
>> From: FreeTDS [mailto:[email protected]] On Behalf Of
>> Frediano Ziglio
>> Sent: 14 June 2016 12:58
>> To: FreeTDS Development Group
>> Subject: Re: [freetds] Old dblib.c bug still there
>>
>> 2016-06-12 18:59 GMT+01:00 Nem W Schlecht <[email protected]>:
>> > Hello all,
>> >
>> > First off, I just want to thank all of the developers in this
>> > community for continuing work on such a useful and excellent
>> > application.  I cannot thank and appreciate you all enough!  Thank
>> > you,
>> Thank You, THANK YOU!!
>> >
>> >
>> > I recently grabbed the last stable release and came across an issue
>> > that seems to constantly be plaguing me and has been around for a
>> > long time.  I had reported this back in July of 2014, but the
>> > proposed solution (stripping all but one space) would still screw up
>> > some of my stored procedures (that have lots of spaces in strings
>> > for formatting
>> purposes).
>> >
>> > My original post and reply:
>> >   http://lists.ibiblio.org/pipermail/freetds/2014q3/028964.html
>> >   http://lists.ibiblio.org/pipermail/freetds/2014q3/028966.html
>> >
>> > The issue is with lines 7311-7314 in dblib.c:
>> >
>> >    7311                 case NTBSTRINGBIND: /* strip trailing blanks,
>> null
>> > term */
>> >    7312                     while (srclen && src[srclen - 1] == ' ') {
>> >    7313                         --srclen;
>> >    7314                     }
>> >
>> > Looks like something good to do, right?  Get rid of any blanks that
>> > we don't need.  However, this keeps messing up my output when I use
>> "defncopy"
>> > to dump out some of my stored procedures.
>> >
>>
>> Well... this is the expected behaviour of NTBSTRINGBIND. The problem
>> is not in dblib.c but in defncopy that expects a different behaviour.
>>



-- 
Nem W Schlecht
 "Perl did the magic.  I just waved the wand."

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diff --git a/freetds-1.00.3/src/apps/defncopy.c b/freetds-1.00.3-defncopyfix/src/apps/defncopy.c
index e76d1b3..4890492 100644
--- a/freetds-1.00.3/src/apps/defncopy.c
+++ b/freetds-1.00.3-defncopyfix/src/apps/defncopy.c
@@ -574,7 +574,7 @@ print_results(DBPROCESS *dbproc)
 			assert(sizeof(sql_text) >= dbcollen(dbproc, ctext));
 			return 0;
 		}
-		erc = dbbind(dbproc, ctext, NTBSTRINGBIND, sizeof(sql_text), (BYTE *) sql_text);
+		erc = dbbind(dbproc, ctext, STRINGBIND, 0, (BYTE *) sql_text);
 		if (erc == FAIL) {
 			fprintf(stderr, "%s:%d: dbbind(), column %d failed\n", options.appname, __LINE__, ctext);
 			return -1;