Editing option value for checkbox field fails to update custom_values if multiple values selected

This affects checkbox custom fields, not tested with multiple select fields but may affect those too.
When using the UI to edit the value of an option for such a field, the char_data field of relevant rows in the civicrm_custom_value table is updated accordingly, but only if there was only a single option selected.
E.g. I edited the value of an option from "9" to "09". char_data "9" was updated to "09", but char_data "2|5|9|12" (using "|" for [Ctrl-A]) was not updated.

Donald Lobo says this is not fixed by CRM-1008, "Custom Checkbox and Multi-select Fields - Store and Handle Leading and Trailing Delimiter (Ctrl A)" and asked me to file this issue. See http://lists.civicrm.org/lists/arc/civicrm-dev/2006-07/msg00310.html