Allow to call nextPage and previousPage without REQUEST parameter

if REQUEST exists then redirection is performed. So listbox is rendered
uselessly.

product/ERP5Form/Tool/SelectionTool.py

@@ -793,7 +793,8 @@ class SelectionTool( BaseTool, SimpleItem ):
       return self.checkAll(list_selection_name, uids, REQUEST=REQUEST)
 
     security.declareProtected(ERP5Permissions.View, 'nextPage')
-    def nextPage(self, list_selection_name, listbox_uid, uids=None, REQUEST=None):
+    def nextPage(self, list_selection_name, listbox_uid, uids=None,
+                 list_start=0, REQUEST=None):
       """
         Access the next page of a list
       """
@@ -802,6 +803,7 @@ class SelectionTool( BaseTool, SimpleItem ):
       if selection is not None:
         params = selection.getParams()
         lines = int(params.get('list_lines', 0))
+        if REQUEST is not None:
           form = REQUEST.form
           if form.has_key('page_start'):
             try:
@@ -816,7 +818,8 @@ class SelectionTool( BaseTool, SimpleItem ):
       return self.checkAll(list_selection_name, uids, REQUEST=REQUEST)
 
     security.declareProtected(ERP5Permissions.View, 'previousPage')
-    def previousPage(self, list_selection_name, listbox_uid, uids=None, REQUEST=None):
+    def previousPage(self, list_selection_name, listbox_uid, uids=None,
+                     list_start=0, REQUEST=None):
       """
         Access the previous page of a list
       """
@@ -825,6 +828,7 @@ class SelectionTool( BaseTool, SimpleItem ):
       if selection is not None:
         params = selection.getParams()
         lines = int(params.get('list_lines', 0))
+        if REQUEST is not None:
           form = REQUEST.form
           if form.has_key('page_start'):
             try: