Smart groups involving activity type or status break on 4.6 upgrade

See https://issues.civicrm.org/jira/browse/CRM-17313?focusedCommentId=81459&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-81459

I'm seeing an issue on a 4.4 to 4.6.10 upgrade, with smart groups that specify activity type or status.

In the example I'm looking at, when checking the criteria for this smart group in the Civi UI, we get:

in 4.4:
"Activity Type IN Renew membership request" = activity_type_id 68 - correct;
Activity Status: Scheduled or Completed - correct (though not shown in qill);

in 4.6:
"Activity Type ID In Meeting" = activity_type_id 1 - INCORRECT;
"Activity Status In 1, 1" - INCORRECT.

In the 4.4 database, the civicrm_saved_search.form_values field has this excerpt for activity_type_id:

s:16:"activity_type_id";a:1:{i:68;s:1:"1";}

which unserializes as:

    [activity_type_id] => Array
        (
            [68] => 1
        )

Nothing in form_values for activity_status.

civicrm_saved_search.where_clause has this excerpt for activity_type_id:

  civicrm_activity.activity_type_id IN ('68')

with nothing for activity_status.

In the upgraded 4.6 db, the entries for activity_type_id are unchanged; a new entry has appeared in form_values for activity_status:

s:15:"activity_status";a:2:{i:1;s:1:"1";i:2;s:1:"1";}

which unserializes as:

    [activity_status] => Array
        (
            [1] => 1
            [2] => 1
        )

along with a new entry in where_clause:

civicrm_activity.status_id IN ('1','2')

If I create a new saved search in 4.6 with criteria "Activity Type IN Renew membership request" and look at what gets created in civicrm_saved_search, the excerpt for activity_type_id in form_values is:

  s:16:"activity_type_id";a:1:{s:2:"IN";a:1:{i:0;s:2:"68";}}

which unserializes as:

    [activity_type_id] => Array
        (
            [IN] => Array
                (
                    [0] => 68
                )
        )

and for activity_status:

s:18:"activity_status_id";a:1:{s:2:"IN";a:2:{i:0;s:1:"1";i:1;s:1:"2";}}

which unserializes as:

    [activity_status_id] => Array
        (
            [IN] => Array
                (
                    [0] => 1
                    [1] => 2
                )
        )

In terms of the data format change, these changes look similar to the participant_status_id issue described in CRM-16922. From my reading of that issue, the fix there doesn't migrate old smart group data, it works around the presence of old-format data. But it seems not to have helped in the present case.