In-place edit of custom field option value: existing custom data not updated

See http://forum.civicrm.org/index.php/topic,28037.0.html :

Tested in 4.3.beta3 (also 4.2.6):

When editing a custom field option value the old-fashioned way, when the value is changed, the existing custom data in the relevant civicrm_value_% table is updated: any instances of the old value are replaced with the new.

When editing the option values with the new in-place edit, this does not happen.

In a way it's a data integrity issue: as far as people accessing the data from the UI are concerned (i.e. users), the data for the changed option will have disappeared. And if someone changed a few values such that one of the new values was the same as one of the old ones (perfectly plausible e.g. if using numeric values), then erroneous data would be shown.