[ace-users] Division by zero in ACE_Stats::quotient() method

[Vural, Okan]

Hello Johnny,

I didn't know you switched to GIT. Thank you for the Info.

Anyway, Problem is obvious and methods seem unchanged (Lines 276 and 307) : https://github.com/DOCGroup/ATCD/blob/master/ACE/ace/Stats.cpp
We don’t use & call Stats methods. We don’t have unit tests either. Problem was detected by our Static Code Analysis Tool. It can clearly be seen in the methods. So, I wanted to inform the community about this.

Best Regards
Okan

-----Ursprüngliche Nachricht-----
Von: Johnny Willemsen [mailto:jwillemsen at remedy.nl] 
Gesendet: Donnerstag, 1. Oktober 2015 09:05
An: Vural, Okan; ace-users at list.isis.vanderbilt.edu
Betreff: Re: [ace-users] Division by zero in ACE_Stats::quotient() method

Hi,

Please always use the PRF form, that always helps. The ACE code is not maintained anymore through svn, it is all on github, see https://github.com/DOCGroup/ATCD/.

Could you extend one of our unit tests under ACE_wrappers/tests (or add a new one) and create a pull request which resolves this issue. Maybe for this kind of problems it can also help to check the Coverity results for ATCD, see https://scan.coverity.com/projects/1

Best regards,

Johnny Willemsen
Remedy IT

On 10/01/2015 09:00 AM, Vural, Okan wrote:
> Hello All,
>  
> In the both “ACE_Stats::quotient” methods there seems a potential 
> division by zero problem (See below). It is independent of platform, 
> this is why I didn’t send the problem in a Problem Report. And I 
> checked the latest version in ACE SVN as well. It seems still same in 
> the latest version.
>  
> *ACE Version     **:* V 630
> *File             :* Stats.cpp
> *Method  **:*
>  
> *void*
> *ACE_Stats::quotient* (*const* ACE_UINT64 dividend,
>                      *const* ACE_UINT32 divisor,
>                      ACE_Stats_Value &quotient) {
>   // The whole part of the division comes from simple integer division.
>   quotient.whole (*static_cast*<ACE_UINT32> (divisor == 0
>                                            ?  0  :  dividend / 
> divisor));
>  
>   *if* (quotient.precision () > 0  *||  divisor == 0*)
>     {
>       *const* ACE_UINT32 field = quotient.fractional_field (); …
>       quotient.fractional (*static_cast*<ACE_UINT32> (
>                              dividend % divisor * field / *divisor*));
>  
> With best regards,
> Okan Vural
>  
> 
> 
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