1 files changed, 14 insertions, 3 deletions
diff --git a/phpBB/phpbb/db/tools/tools.php b/phpBB/phpbb/db/tools/tools.php
index 2f891e43d5..c3352a1f66 100644
--- a/phpBB/phpbb/db/tools/tools.php
+++ b/phpBB/phpbb/db/tools/tools.php
@@ -576,7 +576,7 @@ class tools implements tools_interface
 			{
 				foreach ($indexes as $index_name)
 				{
-					if (!$this->sql_index_exists($table, $index_name))
+					if (!$this->sql_index_exists($table, $index_name) && !$this->sql_unique_index_exists($table, $index_name))
 					{
 						continue;
 					}
@@ -1561,7 +1561,8 @@ class tools implements tools_interface
 	 */
 	protected function check_index_name_length($table_name, $index_name, $throw_error = true)
 	{
-		if (strlen($index_name) > 30)
+		$max_index_name_length = $this->get_max_index_name_length();
+		if (strlen($index_name) > $max_index_name_length)
 		{
 			// Try removing the table prefix if it's at the beginning
 			$table_prefix = substr(CONFIG_TABLE, 0, -6); // strlen(config)
@@ -1582,7 +1583,7 @@ class tools implements tools_interface
 
 			if ($throw_error)
 			{
-				trigger_error("Index name '$index_name' on table '$table_name' is too long. The maximum is 30 characters.", E_USER_ERROR);
+				trigger_error("Index name '$index_name' on table '$table_name' is too long. The maximum is $max_index_name_length characters.", E_USER_ERROR);
 			}
 		}
 
@@ -1590,6 +1591,16 @@ class tools implements tools_interface
 	}
 
 	/**
+	 * Get maximum index name length. Might vary depending on db type
+	 *
+	 * @return int Maximum index name length
+	 */
+	protected function get_max_index_name_length()
+	{
+		return 30;
+	}
+
+	/**
 	 * {@inheritDoc}
 	 */
 	function sql_list_index($table_name)