when xxx_add fails because of a dupe_check, return the xxx_id.

Using the dupe_check option would be much nicer if in case a dupe is found, the id of that dupe would be returned. That is, after calling civicrm_contact_add, the result should contain the field contact_id, even if no new record was created because a matching contact was already present in the database. Samefor civicrm_contribution_add, etc.

Right now, an add-opetation that failes because of a dupe-check returns something like this:
[is_error] => 1
[error_message] => Found matching contacts: 107

It would be much nicer to have this:
[is_error] => 1
[error_message] => Found matching contacts: 107
[contact_id] => 107

This way, the subsequent code could use the resulting contact_id, never mind if it was newly created or not. As it is now, the options are:

• detect if the request failed because of a dupe check based on the error message. then:
  a) parse the message to fetch the id, or
  b) start a search query to find the id

both options are not very good.