Do not show duplicated results when multiple comments match

app/Filter/TaskCommentFilter.php

@@ -5,6 +5,7 @@ namespace Kanboard\Filter;
 use Kanboard\Core\Filter\FilterInterface;
 use Kanboard\Model\CommentModel;
 use Kanboard\Model\TaskModel;
+use PicoDb\Database;
 
 /**
  * Filter tasks by comment
@@ -14,6 +15,14 @@ use Kanboard\Model\TaskModel;
  */
 class TaskCommentFilter extends BaseFilter implements FilterInterface
 {
+    /**
+     * Database object
+     *
+     * @access private
+     * @var Database
+     */
+    private $db;
+
     /**
      * Get search attribute
      *
@@ -25,6 +34,19 @@ class TaskCommentFilter extends BaseFilter implements FilterInterface
         return array('comment');
     }
 
+    /**
+     * Set database object
+     *
+     * @access public
+     * @param  Database $db
+     * @return $this
+     */
+    public function setDatabase(Database $db)
+    {
+        $this->db = $db;
+        return $this;
+    }
+
     /**
      * Apply filter
      *
@@ -33,9 +55,28 @@ class TaskCommentFilter extends BaseFilter implements FilterInterface
      */
     public function apply()
     {
-        $this->query->ilike(CommentModel::TABLE.'.comment', '%'.$this->value.'%');
-        $this->query->join(CommentModel::TABLE, 'task_id', 'id', TaskModel::TABLE);
+        $task_ids = $this->getTaskIdsWithGivenComment();
+
+        if (empty($task_ids)) {
+            $task_ids = array(-1);
+        }
+
+        $this->query->in(TaskModel::TABLE.'.id', $task_ids);
 
         return $this;
     }
+
+    /**
+     * Get task ids having this comment
+     *
+     * @access public
+     * @return array
+     */
+    protected function getTaskIdsWithGivenComment()
+    {
+        return $this->db
+            ->table(CommentModel::TABLE)
+            ->ilike(CommentModel::TABLE.'.comment', '%'.$this->value.'%')
+            ->findAllByColumn(CommentModel::TABLE.'.task_id');
+    }
 }