Fix missing attributes in copying products

src/pretix/base/models/items.py

@@ -231,6 +231,8 @@ class Item(LoggedModel):
                     'empty or set it to 0, there is no special limit for this product. The limit for the maximum '
                     'number of items in the whole order applies regardless.')
     )
+    # !!! Attention: If you add new fields here, also add them to the copying code in
+    # pretix/control/views/item.py if applicable.
 
     class Meta:
         verbose_name = _("Product")

src/pretix/control/views/item.py

@@ -801,6 +801,8 @@ class ItemCreate(EventPermissionRequiredMixin, CreateView):
             form.instance.require_voucher = form.cleaned_data['copy_from'].require_voucher
             form.instance.hide_without_voucher = form.cleaned_data['copy_from'].hide_without_voucher
             form.instance.allow_cancel = form.cleaned_data['copy_from'].allow_cancel
+            form.instance.min_per_order = form.cleaned_data['copy_from'].min_per_order
+            form.instance.max_per_order = form.cleaned_data['copy_from'].max_per_order
 
         ret = super().form_valid(form)
         form.instance.log_action('pretix.event.item.added', user=self.request.user, data={