Fixed explicit dft model builder.

src/storm-dft/builder/ExplicitDFTModelBuilder.cpp

@@ -141,6 +141,7 @@ namespace storm {
             storm::storage::sparse::ModelComponents<ValueType> components(std::move(modelComponents.transitionMatrix), std::move(modelComponents.stateLabeling));
                     components.exitRates = std::move(modelComponents.exitRates);
             if (deterministic) {
+                components.transitionMatrix.makeRowGroupingTrivial();
                 model = std::make_shared<storm::models::sparse::Ctmc<ValueType>>(std::move(components));
             } else {
                     components.markovianStates = std::move(modelComponents.markovianStates);

src/storm/storage/SparseMatrix.cpp

@@ -1472,6 +1472,16 @@ namespace storm {
             return trivialRowGrouping;
         }
         
+        template<typename ValueType>
+        void SparseMatrix<ValueType>::makeRowGroupingTrivial() {
+            if (trivialRowGrouping) {
+                STORM_LOG_ASSERT(!rowGroupIndices || rowGroupIndices.get() == storm::utility::vector::buildVectorForRange(0, this->getRowGroupCount() + 1), "Row grouping is supposed to be trivial but actually it is not.");
+            } else {
+                trivialRowGrouping = true;
+                rowGroupIndices = boost::none;
+            }
+        }
+        
         template<typename ValueType>
         ValueType SparseMatrix<ValueType>::getRowSum(index_type row) const {
             ValueType sum = storm::utility::zero<ValueType>();

src/storm/storage/SparseMatrix.h

@@ -998,6 +998,12 @@ s             * @param insertDiagonalEntries If set to true, the resulting matri
              * @return True iff the matrix has a trivial row grouping.
              */
             bool hasTrivialRowGrouping() const;
+            
+            /*!
+             * Makes the row grouping of this matrix trivial.
+             * Has no effect when the row grouping is already trivial.
+             */
+            void makeRowGroupingTrivial();
 
 			/*!
 			* Returns a copy of the matrix with the chosen internal data type