JaniNextStateGenerator: Fixed an issue related to CTMCs without state-action rewards

src/storm/generator/JaniNextStateGenerator.cpp

@@ -495,9 +495,11 @@ namespace storm {
                 
                 std::vector<ValueType> stateActionRewards(rewardExpressions.size(), storm::utility::zero<ValueType>());
                 for (auto const& choice : allChoices) {
+                    if (hasStateActionRewards) {
                         for (uint_fast64_t rewardVariableIndex = 0; rewardVariableIndex < rewardExpressions.size(); ++rewardVariableIndex) {
                             stateActionRewards[rewardVariableIndex] += choice.getRewards()[rewardVariableIndex] * choice.getTotalMass() / totalExitRate;
                         }
+                    }
                     
                     if (this->options.isBuildChoiceOriginsSet() && choice.hasOriginData()) {
                         globalChoice.addOriginData(choice.getOriginData());