[petsc-dev] SF broken in master !

[Jed Brown]

Barry Smith <bsmith at mcs.anl.gov> writes:

>   and yet it is not broke in next. I thought that was impossible!

This commit was bad:

  https://bitbucket.org/petsc/petsc/commits/60a1948e59517edd5702a5e277d78229b7015096

Toby pointed it out and fixed it in this commit, which went into 'next':

  https://bitbucket.org/petsc/petsc/commits/38e7336fef8d310d693744ab39306ec09879f8c2

Meanwhile, Matt didn't put this in his branch and went on to make other
changes to SF, including a similar commit:

  https://bitbucket.org/petsc/petsc/commits/9837ea968140067d7f638ef40a3e6ee2b94657e5

Again, Toby pointed out the bug in this commit, which Matt had to
resolve when merging to 'next' because it conflicted with Toby's correct
version.  The tests certainly did not pass in Matt's branch, but they
passed in 'next' because Toby's branch fixed the bug.

Ultimately, Matt merged to 'master' without merging Toby's bug fix.

I have now merged Toby's branch and 'master' works again.  Thanks, Toby.


Note that prior to this merge, the following was the only difference
between 'master' and 'next':

diff --git c/src/vec/is/sf/interface/sf.c w/src/vec/is/sf/interface/sf.c
index af2dc58..26a286a 100644
--- c/src/vec/is/sf/interface/sf.c
+++ w/src/vec/is/sf/interface/sf.c
@@ -794,7 +794,7 @@ PetscErrorCode PetscSFGetMultiSF(PetscSF sf,PetscSF *multi)
     ierr = PetscMalloc1(sf->nleaves,&remote);CHKERRQ(ierr);
     for (i=0; i<sf->nleaves; i++) {
       remote[i].rank  = sf->remote[i].rank;
-      remote[i].index = outoffset[sf->mine ? sf->mine[i] : 1];
+      remote[i].index = outoffset[sf->mine ? sf->mine[i] : i];
     }
     ierr = PetscSFDuplicate(sf,PETSCSF_DUPLICATE_RANKS,&sf->multi);CHKERRQ(ierr);
     ierr = PetscSFSetGraph(sf->multi,inoffset[sf->nroots],sf->nleaves,NULL,PETSC_COPY_VALUES,remote,PETSC_OWN_POINTER);CHKERRQ(ierr);


To avoid this in the future, I suggest

  1. Run tests on topic branches, especially those tests related to the
  modification.  If you're tinkering with SF, the least you can do is
  run the SF tests.

  2. Fix content bugs in the topic branch instead of sneaking it into a
  merge commit that's oh so easy to forget.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 818 bytes
Desc: not available
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20141015/5ebbdc1d/attachment.sig>