fixes #2018 prevent matching tags/albums to show private content

include/functions_tag.inc.php

@@ -37,7 +37,7 @@ function get_nb_available_tags()
  *
  * @return array [id, name, counter, url_name]
  */
-function get_available_tags()
+function get_available_tags($tag_ids=array())
 {
   // we can find top fatter tags among reachable images
   $query = '
@@ -45,14 +45,24 @@ SELECT tag_id, COUNT(DISTINCT(it.image_id)) AS counter
   FROM '.IMAGE_CATEGORY_TABLE.' ic
     INNER JOIN '.IMAGE_TAG_TABLE.' it
     ON ic.image_id=it.image_id
+  WHERE 1=1
   '.get_sql_condition_FandF(
     array(
       'forbidden_categories' => 'category_id',
       'visible_categories' => 'category_id',
       'visible_images' => 'ic.image_id'
       ),
-    ' WHERE '
-    ).'
+    ' AND '
+    );
+
+  if (is_array($tag_ids) and count($tag_ids) > 0)
+  {
+    $query .= '
+    AND tag_id IN ('.implode(',', $tag_ids).')
+';
+  }
+
+  $query .= '
   GROUP BY tag_id
 ;';
   $tag_counters = query2array($query, 'tag_id', 'counter');