From 6f7db1baa8ae13d0a0ab23cd8497c26668c51b4c Mon Sep 17 00:00:00 2001
From: Stefano Zampini <stefano.zampini@gmail.com>
Date: Tue, 18 Apr 2023 11:18:45 +0300
Subject: [PATCH] PETScWrappers::BlockSparseMatrix unify constructors

add missing test
---
 include/deal.II/lac/petsc_block_sparse_matrix.h  | 15 +++++++++++++--
 source/lac/petsc_parallel_block_sparse_matrix.cc |  3 +++
 tests/petsc/block_matrices_01.cc                 |  1 +
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/include/deal.II/lac/petsc_block_sparse_matrix.h b/include/deal.II/lac/petsc_block_sparse_matrix.h
index 397725d162..63b9edab52 100644
--- a/include/deal.II/lac/petsc_block_sparse_matrix.h
+++ b/include/deal.II/lac/petsc_block_sparse_matrix.h
@@ -100,7 +100,7 @@ namespace PETScWrappers
        * reinit(BlockSparsityPattern). The number of blocks per row and column
        * are then determined by that function.
        */
-      BlockSparseMatrix() = default;
+      BlockSparseMatrix();
 
       /**
        * Create a BlockSparseMatrix with a PETSc Mat that describes the entire
@@ -339,7 +339,7 @@ namespace PETScWrappers
        * a "nested" matrix using PETSc's MATNEST object whose individual
        * blocks are the blocks of this matrix.
        */
-      Mat petsc_nest_matrix = nullptr;
+      Mat petsc_nest_matrix;
 
       /**
        * Utility to setup the MATNEST object
@@ -361,6 +361,12 @@ namespace PETScWrappers
     /** @} */
 
     // ------------- inline and template functions -----------------
+    inline BlockSparseMatrix::BlockSparseMatrix()
+      : BaseClass()
+      , petsc_nest_matrix(nullptr)
+    {}
+
+
 
     inline BlockSparseMatrix::BlockSparseMatrix(const Mat &A)
       : BlockSparseMatrix()
@@ -368,9 +374,12 @@ namespace PETScWrappers
       this->reinit(A);
     }
 
+
+
     template <size_t block_rows, size_t block_columns>
     inline BlockSparseMatrix::BlockSparseMatrix(
       const std::array<std::array<Mat, block_columns>, block_rows> &arrayA)
+      : BlockSparseMatrix()
     {
       this->reinit(block_rows, block_columns);
       this->sub_objects.reinit(block_rows, block_columns);
@@ -385,6 +394,8 @@ namespace PETScWrappers
       this->collect_sizes();
     }
 
+
+
     inline BlockSparseMatrix &
     BlockSparseMatrix::operator=(const double d)
     {
diff --git a/source/lac/petsc_parallel_block_sparse_matrix.cc b/source/lac/petsc_parallel_block_sparse_matrix.cc
index a8faa324eb..798f2e514d 100644
--- a/source/lac/petsc_parallel_block_sparse_matrix.cc
+++ b/source/lac/petsc_parallel_block_sparse_matrix.cc
@@ -260,6 +260,9 @@ namespace PETScWrappers
       ierr = MatCreateNest(
         comm, m, nullptr, n, nullptr, psub_objects.data(), &petsc_nest_matrix);
       AssertThrow(ierr == 0, ExcPETScError(ierr));
+
+      ierr = MatNestSetVecType(petsc_nest_matrix, VECNEST);
+      AssertThrow(ierr == 0, ExcPETScError(ierr));
     }
 
 
diff --git a/tests/petsc/block_matrices_01.cc b/tests/petsc/block_matrices_01.cc
index aca37f1457..9cb37b47a8 100644
--- a/tests/petsc/block_matrices_01.cc
+++ b/tests/petsc/block_matrices_01.cc
@@ -78,6 +78,7 @@ test()
   Assert(tmp2.n_block_cols() == pbsm.n_block_cols(), ExcInternalError());
   Assert(tmp2.m() == pbsm.m(), ExcInternalError());
   Assert(tmp2.n() == pbsm.n(), ExcInternalError());
+  Assert(tmp2.petsc_matrix() == pbsm.petsc_matrix(), ExcInternalError());
   for (unsigned int blr = 0; blr < 2; ++blr)
     {
       for (unsigned int blc = 0; blc < 2; ++blc)
-- 
2.39.5