bugfix

src/core/marketplace.cpp

@@ -31,11 +31,14 @@ int Marketplace::getNextSellerNo()
         [](const std::unique_ptr<Seller>& a, const std::unique_ptr<Seller>& b) -> bool {
             return a->getSellerNo() < b->getSellerNo();
         });
+    if (iter == sellers_.end())
+        return 1;
     return (*iter)->getSellerNo() + 1;
 }
 
 int Marketplace::getNumSellersDelete()
 {
-    int count = std::count_if(sellers_.begin(), sellers_.end(), [](const auto& a){return a->getState() == Seller::State::DELETE;});
+    int count = std::count_if(sellers_.begin(), sellers_.end(),
+                              [](const auto& a) { return a->getState() == Seller::State::DELETE; });
     return count;
 }

src/gui/sellermodel.cpp

@@ -21,6 +21,9 @@ QVariant SellerModel::data(const QModelIndex& index, int role) const
     if (role != Qt::DisplayRole)
         return QVariant();
 
+    if (marketplace_->getSellers().size() == 0)
+        return QVariant();
+
     Seller* seller = marketplace_->getSellers().at(index.row()).get();
 
     /*      if (seller->getState() == Seller::State::DELETE)