[petsc-dev] who broke petsc-dev

[Barry Smith]

PetscErrorCode  KSPSetOperators(KSP ksp,Mat Amat,Mat Pmat,MatStructure flag)
{
  MatNullSpace   nullsp;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(ksp,KSP_CLASSID,1);
  if (Amat) PetscValidHeaderSpecific(Amat,MAT_CLASSID,2);
  if (Pmat) PetscValidHeaderSpecific(Pmat,MAT_CLASSID,3);
  if (Amat) PetscCheckSameComm(ksp,1,Amat,2);
  if (Pmat) PetscCheckSameComm(ksp,1,Pmat,3);
  if (!ksp->pc) {ierr = KSPGetPC(ksp,&ksp->pc);CHKERRQ(ierr);}
  ierr = PCSetOperators(ksp->pc,Amat,Pmat,flag);CHKERRQ(ierr);
  if (ksp->setupstage == KSP_SETUP_NEWRHS) ksp->setupstage = KSP_SETUP_NEWMATRIX;  /* so that next solve call will call PCSetUp() on new matrix */
  if (ksp->guess) {
    ierr = KSPFischerGuessReset(ksp->guess);CHKERRQ(ierr);
  }
  ierr = MatGetNullSpace(Amat, &nullsp);CHKERRQ(ierr);
  if (nullsp) {
    ierr = KSPSetNullSpace(ksp, nullsp);CHKERRQ(ierr);
  }
  PetscFunctionReturn(0);
}


1) It is legitimate to call KSPSetOperators with a null Amat so this is a bug that crashes large parts of PETSc

2) Do you really want to do this? I am not sure I like it.