erp5_core: update Base_edit so that it does not add two slashes in the computed url

Also, cleanup trailing whitespaces and unused variable.

new_url was not computated correctly either,
giving instance_url//erp5/...

product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_core/Base_edit.py

@@ -25,9 +25,12 @@ if dialog_id not in ('', None):
 # Prevent users who don't have rights to edit the object from
 # editing it by calling the Base_edit script with correct
 # parameters directly.
+
 if not silent_mode and not request.AUTHENTICATED_USER.has_permission('Modify portal content', context) :
   msg = Base_translateString("You do not have the permissions to edit the object.")
-  redirect_url = '%s/%s?selection_index=%s&selection_name=%s&%s' % (context.absolute_url(), form_id, selection_index, selection_name, 'portal_status_message=%s' % msg)
+  context_absolute_url = context.absolute_url()
+  context_absolute_url = context_absolute_url[:-1] if context_absolute_url.endswith('/') else context_absolute_url
+  redirect_url = '%s/%s?selection_index=%s&selection_name=%s&%s' % (context_absolute_url, form_id, selection_index, selection_name, 'portal_status_message=%s' % msg)
   return request['RESPONSE'].redirect(redirect_url)
 
 # Get the form
@@ -248,12 +251,6 @@ if message_only:
 
 ignore_layout = int(ignore_layout)
 editable_mode = int(editable_mode)
-spp = context.getPhysicalPath()
-spp =list(spp)
-s_url = request["SERVER_URL"]
-spp.insert(0,s_url)
-#calculate direct the url instead of using absolute_url
-new_url = '/'.join(spp)
 
 # for web mode, we should use 'view' instead of passed form_id
 # after 'Save & View'.
@@ -261,18 +258,20 @@ if context.REQUEST.get('is_web_mode', False) and \
     not editable_mode:
   form_id = 'view'
 
+context_absolute_url = context.absolute_url()
+context_absolute_url = context_absolute_url[:-1] if context_absolute_url.endswith('/') else context_absolute_url
+
 if not selection_index:
   redirect_url = '%s/%s?ignore_layout:int=%s&editable_mode:int=%s&portal_status_message=%s' % (
-                                  context.absolute_url(),
+                                  context_absolute_url,
                                   form_id,
                                   ignore_layout,
                                   editable_mode,
                                   message)
 
-
 else:
   redirect_url = '%s/%s?selection_index=%s&selection_name=%s&ignore_layout:int=%s&editable_mode=%s&portal_status_message=%s' % (
-                              context.absolute_url(),
+                              context_absolute_url,
                               form_id,
                               selection_index,
                               selection_name,
@@ -280,7 +279,6 @@ else:
                               editable_mode,
                               message)
 
-
 result = request['RESPONSE'].redirect(redirect_url)
 
 if silent_mode: return result, 'redirect'