I tested your fix (on top of master) with my original PetIGA reproducer, and the issue seems to be fixed.

On Wed, 20 Feb 2019 at 08:32, Jed Brown <jed@jedbrown.org> wrote:
Yuck, bad bug.  I pushed a one-line fix to your branch.  Can you let me
know if there are any outstanding issues?  If it solves the problem for
you, I'll cherry-pick it to 'maint'.  Thanks.

Stefano Zampini <stefano.zampini@gmail.com> writes:

> In the link I have sent you, ex29 was modified to invert the order of values set. There’s also a command line that shows the error
>
> mpiexec -n 3 ./ex29 -n 4 -invert -bs 2
>
>
> I have added the correct output, but if you run with bts you’ll see some of the entries are scrambled up.
>
>
>> On Feb 20, 2019, at 1:27 AM, Jed Brown <jed@jedbrown.org> wrote:
>>
>> Is this what I'm supposed to see?  What should I be looking at?
>>
>> $ mpiexec.hydra -n 3 mpich-clang/tests/vec/vec/examples/tests/ex29 -n 126 -info | grep malloc
>> [0] VecAssemblyBegin_MPI_BTS(): Stash has 252 entries, uses 2 mallocs.
>> [0] VecAssemblyBegin_MPI_BTS(): Block-Stash has 0 entries, uses 0 mallocs.
>> [0] VecAssemblyBegin_MPI_BTS(): Stash has 0 entries, uses 0 mallocs.
>> [0] VecAssemblyBegin_MPI_BTS(): Block-Stash has 252 entries, uses 2 mallocs.
>>
>> $ mpiexec.hydra -n 3 mpich-clang/tests/vec/vec/examples/tests/ex29 -n 126 -vec_assembly_legacy -info | grep malloc
>> [0] VecAssemblyBegin_MPI(): Stash has 252 entries, uses 2 mallocs.
>> [0] VecAssemblyBegin_MPI(): Block-Stash has 0 entries, uses 0 mallocs.
>> [0] VecAssemblyBegin_MPI(): Stash has 0 entries, uses 0 mallocs.
>> [0] VecAssemblyBegin_MPI(): Block-Stash has 252 entries, uses 2 mallocs.
>>
>> Stefano Zampini <stefano.zampini@gmail.com> writes:
>>
>>> Jed,
>>>
>>> I’m resurrecting this thread since I believe this bug has not yet been fixed.
>>> I have spent a couple of hours today tracking down a bug in my code, that I finally confined to be related with VecSetValuesBlocked.
>>>
>>> I have pushed an example that shows the problem here https://bitbucket.org/petsc/petsc/commits/1cb7fb90b416ce1d4e4767a0d5a2ef5043656d53?at=stefano_zampini/feature-pcbddc-enablelor <https://bitbucket.org/petsc/petsc/commits/1cb7fb90b416ce1d4e4767a0d5a2ef5043656d53?at=stefano_zampini/feature-pcbddc-enablelor>
>>>
>>> Could you please have a look?
>>>
>>> Thanks,
>>> Stefano
>>>
>>>> On Apr 24, 2016, at 10:52 PM, Jed Brown <jed@jedbrown.org> wrote:
>>>>
>>>> Lisandro Dalcin <dalcinl@gmail.com> writes:
>>>>
>>>>> Do you remember about this regression? My PetIGA tests are still
>>>>> failing with petsc/master.
>>>>
>>>> Yes, I have most of a fix in a branch that I'm working to finish.


--
Lisandro Dalcin
============
Research Scientist
Computer, Electrical and Mathematical Sciences & Engineering (CEMSE)
Extreme Computing Research Center (ECRC)
King Abdullah University of Science and Technology (KAUST)
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