Function fix_serialized_columns() fixes only topic subjects. There should be code for groups also.
$request = $smcFunc['db_query']('', '
SELECT id_action, extra
FROM {db_prefix}log_actions
WHERE action IN ({string:id_group}, {string:additional_groups})',
array(
'id_group' => 'id_group',
'additional_groups' => 'additional_groups',
)
);
while ($row = $smcFunc['db_fetch_assoc']($request)) {
if (safe_unserialize($row['extra']) === false && preg_match('~^(a:3:{s:8:"previous";s:)(\d+):"(.*)"(;s:3:"new";s:)(\d+):"(.*)"(;s:10:"applicator";s:\d+:"\d+";})$~',
$row['extra'], $matches) === 1) {
$smcFunc['db_query']('', '
UPDATE {db_prefix}log_actions
SET extra = {string:extra}
WHERE id_action = {int:current_action}',
array(
'current_action' => $row['id_action'],
'extra' => $matches[1] . strlen($matches[3]) . ':"' . $matches[3] . '"' . $matches[4] . strlen($matches[6]) . ':"' . $matches[6] . '"' . $matches[7],
)
);
}
}
$smcFunc['db_free_result']($request);
This is unlikely to be fixed in 2.0 but really should be added to 2.1 if it isn't already.
I found some other serialized actions in smf_log_actions table which needs to be fixed after conversion. Here my version of fix_serialized_columns function.
https://github.com/realdigger/SMF-Fix-Serialized-Strings-After-Conversion