prevent errors in changing pages when listbox is modified background.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@24543 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Form/SelectionTool.py

@@ -632,7 +632,6 @@ class SelectionTool( BaseTool, UniqueObject, SimpleItem ):
         lastPage.
       """
       if uids is None: uids = []
-      selection = self.getSelectionFor(list_selection_name, REQUEST)
       REQUEST.form['list_start'] = 0
       self.uncheckAll(list_selection_name, listbox_uid)
       return self.checkAll(list_selection_name, uids, REQUEST=REQUEST)
@@ -647,6 +646,7 @@ class SelectionTool( BaseTool, UniqueObject, SimpleItem ):
       """
       if uids is None: uids = []
       selection = self.getSelectionFor(list_selection_name, REQUEST)
+      if selection is not None:
         params = selection.getParams()
         # XXX This will not work if the number of lines shown in the listbox is greater
         #       than the BIG_INT constan. Such a case has low probability but is not
@@ -668,6 +668,7 @@ class SelectionTool( BaseTool, UniqueObject, SimpleItem ):
       """
       if uids is None: uids = []
       selection = self.getSelectionFor(list_selection_name, REQUEST)
+      if selection is not None:
         params = selection.getParams()
         lines = params.get('list_lines', 0)
         start = REQUEST.form.pop('list_start', 0)
@@ -683,6 +684,7 @@ class SelectionTool( BaseTool, UniqueObject, SimpleItem ):
       """
       if uids is None: uids = []
       selection = self.getSelectionFor(list_selection_name, REQUEST)
+      if selection is not None:
         params = selection.getParams()
         lines = params.get('list_lines', 0)
         start = REQUEST.form.pop('list_start', 0)
@@ -698,6 +700,7 @@ class SelectionTool( BaseTool, UniqueObject, SimpleItem ):
       """
       if uids is None: uids = []
       selection = self.getSelectionFor(list_selection_name, REQUEST)
+      if selection is not None:
         params = selection.getParams()
         params['list_start'] = int(REQUEST.form.pop('list_start', 0))
         selection.edit(params=params)