diff --git a/phpBB/phpbb/search/base.php b/phpBB/phpbb/search/base.php
index e7d0774b6c..e33dfc8f75 100644
--- a/phpBB/phpbb/search/base.php
+++ b/phpBB/phpbb/search/base.php
@@ -76,17 +76,10 @@ class base
 				}
 			}
 
-			// change the start to the actual end of the current request if the sort direction differs
-			// from the dirction in the cache and reverse the ids later
+			// If the sort direction differs from the direction in the cache, then reverse the ids array
 			if ($reverse_ids)
 			{
-				$start = $result_count - $start - $per_page;
-
-				// the user requested a page past the last index
-				if ($start < 0)
-				{
-					return SEARCH_RESULT_NOT_IN_CACHE;
-				}
+				$stored_ids = array_reverse($stored_ids);
 			}
 
 			for ($i = $start, $n = $start + $per_page; ($i < $n) && ($i < $result_count); $i++)
@@ -102,11 +95,6 @@ class base
 			}
 			unset($stored_ids);
 
-			if ($reverse_ids)
-			{
-				$id_ary = array_reverse($id_ary);
-			}
-
 			if (!$complete)
 			{
 				return SEARCH_RESULT_INCOMPLETE;
diff --git a/tests/functional/search/base.php b/tests/functional/search/base.php
index 0e3aa80fa3..e5ee1feee3 100644
--- a/tests/functional/search/base.php
+++ b/tests/functional/search/base.php
@@ -49,6 +49,30 @@ abstract class phpbb_functional_search_base extends phpbb_functional_test_case
 		$this->assertStringContainsString("Search found $topics_found match", $crawler->filter('.searchresults-title')->text(), $this->search_backend);
 	}
 
+	protected function assert_search_posts_by_author_id($author_id, $posts_found, $sort_key = '', $sort_dir = '')
+	{
+		// Test obtaining data from cache if sorting direction is set
+		if (!$sort_dir)
+		{
+			$this->purge_cache();
+		}
+		$crawler = self::request('GET', 'search.php?author_id=' . $author_id . ($sort_key ? "&sk=$sort_key" : '') . ($sort_dir ? "&sk=$sort_dir" : ''));
+		$this->assertEquals($posts_found, $crawler->filter('.postbody')->count(), $this->search_backend);
+		$this->assertStringContainsString("Search found $posts_found match", $crawler->filter('.searchresults-title')->text(), $this->search_backend);
+	}
+
+	protected function assert_search_topics_by_author_id($author_id, $topics_found, $sort_key = '', $sort_dir = '')
+	{
+		// Test obtaining data from cache if sorting direction is set
+		if (!$sort_dir)
+		{
+			$this->purge_cache();
+		}
+		$crawler = self::request('GET', 'search.php?sr=topics&author_id=' . $author_id . ($sort_key ? "&sk=$sort_key" : '') . ($sort_dir ? "&sk=$sort_dir" : ''));
+		$this->assertEquals($topics_found, $crawler->filter('.row')->count(), $this->search_backend);
+		$this->assertStringContainsString("Search found $topics_found match", $crawler->filter('.searchresults-title')->text(), $this->search_backend);
+	}
+
 	protected function assert_search_in_topic($topic_id, $keywords, $posts_found, $sort_key = '')
 	{
 		$this->purge_cache();
@@ -93,10 +117,14 @@ abstract class phpbb_functional_search_base extends phpbb_functional_test_case
 		$this->add_lang('common');
 
 		// Create a new standard user if needed, topic and post to test searh for author
-		if (!$this->user_exists('searchforauthoruser'))
+		if (!$searchforauthoruser_id = $this->user_exists('searchforauthoruser'))
 		{
 			$searchforauthoruser_id = $this->create_user('searchforauthoruser');
 		}
+		else
+		{
+			$searchforauthoruser_id = key($searchforauthoruser_id);
+		}
 		$this->remove_user_group('NEWLY_REGISTERED', ['searchforauthoruser']);
 		$this->set_flood_interval(0);
 		$this->login('searchforauthoruser');
@@ -161,6 +189,11 @@ abstract class phpbb_functional_search_base extends phpbb_functional_test_case
 
 			$this->assert_search_posts_by_author('searchforauthoruser', 2, $sort_key);
 			$this->assert_search_topics_by_author('searchforauthoruser', 1, $sort_key);
+
+			$this->assert_search_posts_by_author_id($searchforauthoruser_id, 2, $sort_key);
+			$this->assert_search_topics_by_author_id($searchforauthoruser_id, 1, $sort_key);
+			$this->assert_search_posts_by_author_id($searchforauthoruser_id, 2, $sort_key, 'a'); //search asc order
+			$this->assert_search_topics_by_author_id($searchforauthoruser_id, 1, $sort_key, 'a'); // search asc order
 		}
 
 		$this->assert_search_not_found('loremipsumdedo');
diff --git a/tests/test_framework/phpbb_functional_test_case.php b/tests/test_framework/phpbb_functional_test_case.php
index 9e4cb364d0..6f8bc2d013 100644
--- a/tests/test_framework/phpbb_functional_test_case.php
+++ b/tests/test_framework/phpbb_functional_test_case.php
@@ -1523,9 +1523,9 @@ class phpbb_functional_test_case extends phpbb_test_case
 	* @param string $username The username to check or empty if user_id is used
 	* @param int $user_id The user id to check or empty if username is used
 	*
-	* @return bool Returns true if a user exists, false otherwise
+	* @return array Returns user_id => username array or empty array if user does not exist
 	*/
-	protected function user_exists($username, $user_id = null)
+	protected function user_exists($username = '', $user_id = '')
 	{
 		global $db;
 
@@ -1540,6 +1540,8 @@ class phpbb_functional_test_case extends phpbb_test_case
 			require_once(__DIR__ . '/../../phpBB/includes/functions_user.php');
 		}
 
-		return user_get_id_name($user_id, $username) ? false : true;
+		user_get_id_name($user_id, $username, false, true);
+
+		return $username;
 	}
 }