Index: openacs-4/packages/acs-subsite/tcl/group-type-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-subsite/tcl/group-type-procs.tcl,v
diff -u -r1.12.2.3 -r1.12.2.4
--- openacs-4/packages/acs-subsite/tcl/group-type-procs.tcl	3 Mar 2020 18:38:15 -0000	1.12.2.3
+++ openacs-4/packages/acs-subsite/tcl/group-type-procs.tcl	1 Sep 2020 17:38:56 -0000	1.12.2.4
@@ -30,10 +30,12 @@
             set user_id [ad_conn user_id]
         }
         return [db_string group_exists_p {
-            select exists (select 1 from acs_objects o
-                           where object_type = :group_type
-                             and not acs_permission.permission_p(o.object_id, :user_id, 'delete'))
-              from dual
+            select case when exists
+            (select 1 from acs_objects o
+             where object_type = :group_type
+             and not acs_permission.permission_p(o.object_id, :user_id, 'delete'))
+            then 1 else 0 end
+            from dual
         }]
     }
 
@@ -241,7 +243,9 @@
             }
 
             if { [db_string type_exists {
-                select exists (select 1 from acs_object_types t where t.object_type = :group_type)
+                select case when exists
+                (select 1 from acs_object_types t where t.object_type = :group_type)
+                then 1 else 0 end
                 from dual
             }] } {
                 db_exec_plsql drop_type {}