[gmx-developers] Memory allocation bug in g_traj (cvs + 3.3.1)

[hessb at mpip-mainz.mpg.de]

> Hello All,
>
> I encountered a little (and easy to fix) bug in gmx_traj.c,
> in cvs it is at line 571, in 3.3.1 line 553.
> -> isize[i] = atndx[index0[0][i]+1] - atndx[index0[0][i]];
> isize[i] can become negative in some cases what results in the attempt
> to pass a negative number to sfree() and thus a crash.

I guess you mean snew()?

> This is easily fixed by just adding behind the above line.
> if (isize[i] < 0)
>   isize[i] = isize[i] * -1;
>
> Regards,
> Wolfram

But isize[i] should never become negative, unless you pass
an incorrect molecule number (<1 or >#mols).
So we should add a check for that instead of your fix.
Or am I wrong?

Berk.