fixup! ListBox: support rendering empty item as user's input in multi item...

fixup! ListBox: support rendering empty item as user's input in multi item widget having default values.

product/ERP5Form/ListBox.py

@@ -2456,11 +2456,15 @@ class ListBoxHTMLRendererLine(ListBoxRendererLine):
             # user if any. However, it's only possible if keys are unique,
             # so this is skipped if there's no uid.
             # This duplicates some work done by field.render
+            field_key = editable_field.generate_field_key(key=key)
             try:
               display_value = editable_field._get_user_input_value(
-                editable_field.generate_field_key(key=key), request)
+                field_key, request)
             except (KeyError, AttributeError):
-              display_value = original_value
+              if request.get('default_' + field_key) is None:
+                display_value = original_value
+              else:
+                display_value = None
             if isinstance(editable_field.getRecursiveTemplateField().widget,
                           Widget.MultiItemsWidget) and \
                 not isinstance(display_value, list):

[Kirill Smelkov]

@kazuhiko, instead of this and 688420f8 fixups for 8af1da02, maybe it makes more sense to file initial patch for review, give it some time to settle and only then push to master?

Even reviewing yourself after some time with fresh eye helps sometimes...