Display an error message anytime the cart is viewed if it has mixed items (recurring and non-recurring, or too many recurring). Fixes bug #12211.

docs/changelog/7.x.x.txt

@@ -11,6 +11,7 @@
  - fixed #12246: added extra_www_add_properties as properties fix-up hook in child for www_add
  - fixed #12231: Thingy reindex fails on upgrade
  - fixed #12245: Encrypt Login and Display Message on Login conflict
+ - fixed #12211: Recurring Item error message in Cart
 
 7.10.22
  - rfe   #12223: Add date type to content profiling (metadata)

lib/WebGUI/Shop/Cart.pm

@@ -1024,6 +1024,10 @@ sub www_view {
         return $session->style->userStyle($template->process(\%var));
     }
 
+    if ($self->hasMixedItems) {
+        $error{id $self} = $i18n->get('mixed items warning');
+    }
+
     my %var = (
         %{$self->get},
         formHeader              => WebGUI::Form::formHeader($session, { extras => q|id="wgCartId"|, })
@@ -1047,7 +1051,6 @@ sub www_view {
         shippableItemsInCart    => $self->requiresShipping,
     );
 
-
     # get the shipping address    
     my $address = eval { $self->getShippingAddress };
     if (my $e = WebGUI::Error->caught("WebGUI::Error::ObjectNotFound") && $self->get('shippingAddressId')) {