Index: cgi-bin/admin.c
===================================================================
--- cgi-bin/admin.c	(revision 8716)
+++ cgi-bin/admin.c	(working copy)
@@ -492,6 +492,12 @@
 
     request = ippNewRequest(CUPS_GET_PRINTERS);
 
+    ippAddInteger(request, IPP_TAG_OPERATION, IPP_TAG_ENUM, "printer-type",
+		  CUPS_PRINTER_LOCAL);
+    ippAddInteger(request, IPP_TAG_OPERATION, IPP_TAG_ENUM, "printer-type-mask",
+		  CUPS_PRINTER_CLASS | CUPS_PRINTER_REMOTE |
+		      CUPS_PRINTER_IMPLICIT);
+
    /*
     * Do the request and get back a response...
     */
Index: scheduler/ipp.c
===================================================================
--- scheduler/ipp.c	(revision 8716)
+++ scheduler/ipp.c	(working copy)
@@ -1190,6 +1190,12 @@
                 	_("The printer or class was not found."));
 	return;
       }
+      else if (dtype & CUPS_PRINTER_CLASS)
+      {
+        send_ipp_status(con, IPP_BAD_REQUEST,
+			_("Nested classes are not allowed!"));
+        return;
+      }
 
      /*
       * Add it to the class...