message: make ceed diffusion integrator handle nullptr Coefficient
diff: @@ -39,7 +39,13 @@ std::string ceed_path;
  void InitCeedCoeff(Coefficient* Q, CeedData* ptr)
  {
  - if (ConstantCoefficient* coeff = dynamic_cast<ConstantCoefficient*>(Q))
  + if (Q == nullptr)
  + {
  + CeedConstCoeff* ceedCoeff = new CeedConstCoeff{1.0};
  + ptr->coeff_type = CeedCoeff::Const;
  + ptr->coeff = (void*)ceedCoeff;
  + }
  + else if (ConstantCoefficient* coeff = dynamic_cast<ConstantCoefficient*>(Q))
  {
  CeedConstCoeff* ceedCoeff = new CeedConstCoeff{coeff->constant};
  ptr->coeff_type = CeedCoeff::Const;
  