[petsc-dev] FieldSplit error

[Barry Smith]

   I will fix this.

  Barry

> On May 29, 2015, at 10:40 AM, Mark Adams <mfadams at lbl.gov> wrote:
> 
> I have a 2 x 2 MatComposite and PCSetup is hanging because this branch below does "NEED" to be checked. This is in matrix.c around line 7500.  Barry added this a year ago (and the code has been working so I am puzzled).  I commented this code out and it works.
> 
> The 2nd block here is very small and is all on one processor, so all but one proc have (n == rend-rstart).
> 
> This code seems to work in maint, so I am puzzled.  Perhaps this code was merged recently?
> Mark
> 
>   if (!iscol || isrow == iscol) {
> 
>     PetscBool stride;
> 
>     ierr = PetscObjectTypeCompare((PetscObject)isrow,ISSTRIDE,&stride);CHKERRQ(ierr);
> 
>     if (stride) {
> 
>       PetscInt first,step,n,rstart,rend;
> 
>       ierr = ISStrideGetInfo(isrow,&first,&step);CHKERRQ(ierr);
> 
>       if (step == 1) {
> 
>         ierr = MatGetOwnershipRange(mat,&rstart,&rend);CHKERRQ(ierr);
> 
>         if (rstart == first) {
> 
>           ierr = ISGetLocalSize(isrow,&n);CHKERRQ(ierr);
> 
>           if (n == rend-rstart) {
> 
>             /* special case grabbing all rows; NEED to do a global reduction to make sure all processes are doing this */
> 
>             if (cll == MAT_INITIAL_MATRIX) {
> 
>               *newmat = mat;
> 
>               ierr    = PetscObjectReference((PetscObject)mat);CHKERRQ(ierr);
> 
>             }
> 
>             PetscFunctionReturn(0);
> 
>           }
> 
>         }
> 
>       }
> 
>     }
> 
>   }
>