Re: Null Characters in Strings, Version 9.3.1

On 02/18/2014 09:39 PM, Nils Gösche wrote:
> Heikki wrote:
>
>> On 02/18/2014 07:06 PM, Nils Gösche wrote:
>>> I wrote:
>>>
>>>> If I retrieve the value in a C# program using the ODBC driver, I get
>>>> a string that has a null character at position 459, but a total
>>>> length of 487!  The string up to position 458 is correct, but has
>> now
>>>> been extended with a null character and a few junk characters.
>>>
>>> Am I the only one thinking this is a serious bug?
>>
>> Maybe.. I don't have a C# environment to test this with; if you can
>> write a small stand-alone C program to reproduce this and post it, I'll
>> take a look.
>
> Thanks! I have never written an ODBC program in C before. Wow, what a PITA... ;-).

Yep, it's quite verbose :-).

>  I took a little example program from Microsoft's site and adapted it.  The code is attached.

I'm afraid I can't easily compile and execute that either, with all the
Windows-ism's in it. Could you pick one of the regression test cases
(e.g
http://git.postgresql.org/gitweb/?p=psqlodbc.git;a=blob_plain;f=test/src/select-test.c;hb=HEAD),
and modify it to reproduce the problem? And please also include the SQL
statements to create the test table and data.

>  The essential point is at line 353:
>
>      if (wcslen(pThisBinding->wszBuffer) * sizeof(wchar_t) != pThisBinding->indPtr)
>      {
>          wprintf(L"2 * wcslen = %d, indPtr = %d\n", wcslen(pThisBinding->wszBuffer) * sizeof(wchar_t),
>                  pThisBinding->indPtr);
>      }
>      else
>      {
>          wprintf(pThisBinding->fChar ? DISPLAY_FORMAT_C:DISPLAY_FORMAT,
>                  PIPE,
>                  pThisBinding->cDisplaySize,
>                  pThisBinding->cDisplaySize,
>                  pThisBinding->wszBuffer);
>      }
>
> If I run this with version 9.2.1 of the driver (I am using 32 Bit here), it will go to the else clause and print the
valueof the text column. However, if I run this with the latest version, I get the following output: 

Hmm. If you could pinpoint it to the exact commit that changed the
behavior, that would help too.

- Heikki