In the file: /www/bboard/search-subject.tcl

Add bboard_user_can_view_topic_p SQL contained in contributions.tcl patch.

After
  set_form_variables_string_trim_DoubleAposQQ
add
  set user_id [ad_verify_and_get_user_id]

After
  and topic_id = $topic_id
Add
  and bboard_user_can_view_topic_p($user_id,$topic_id) = 't'