message: Fix TODO item in MixedBilinearForm::FormRectangularSystemMatrix
diff: @@ -1763,12 +1763,24 @@ void MixedBilinearForm::FormRectangularSystemMatrix(
  mat->Finalize();
  - if (test_P) // TODO: Must actually check for trial_P too
  + if (test_P && trial_P)
  {
  SparseMatrix *m = RAP(*test_P, *mat, *trial_P);
  delete mat;
  mat = m;
  }
  + else if (test_P)
  + {
  + SparseMatrix *m = mfem::Mult(*test_P, *mat);
  + delete mat;
  + mat = m;
  + }
  + else if (trial_P)
  + {
  + SparseMatrix *m = mfem::Mult(*mat, *trial_P);
  + delete mat;
  + mat = m;
  + }
  Array<int> ess_trial_tdof_marker, ess_test_tdof_marker;
  FiniteElementSpace::ListToMarker(trial_tdof_list, trial_fes->GetTrueVSize(),
  