On Tue, Feb 23, 2010 at 8:46 AM, Ronald Oussoren <report@bugs.python.org> wrote:
> ..
> I get test failures, but no crashes, when I do run the additional tests.

The crash that I see is apparently due to underallocated  memory:

 alt_grouplist = PyMem_Malloc(n);

should be

 alt_grouplist = PyMem_Malloc(n * sizeof(gid_t));

..
> I'm not too thrilled about your approach of growing the grouplist argument of
> getgroups until the results fit, the comment in the coreutils sources refers to two > very old unix flavors and IMHO it is not worthwhile to try to support those.
>

You are probably right on this point, but the main issue with using
getgroups(0, ..) is the race condition that it introduces.  If another
thread adds a group between n = getgroups(0, ..) and getgroups(n, ..)
calls, the second call will fail.

Makes sense regardless of the approach.