rdbms: make $wgSQLMode work as documented when it is NULL

NULL means that the SET query should not be sent.
This was broken since 5bc9b990acd0e0302f.

Change-Id: I148b1153ef6ecca99c56e4f63247820a766ae779

diff --git a/includes/libs/rdbms/database/DatabaseMysqlBase.php b/includes/libs/rdbms/database/DatabaseMysqlBase.php
index 7fccd57..36c947f 100644 (file)
--- a/includes/libs/rdbms/database/DatabaseMysqlBase.php
+++ b/includes/libs/rdbms/database/DatabaseMysqlBase.php
@@ -106,7 +106,7 @@ abstract class DatabaseMysqlBase extends Database {
                                $this->$var = $params[$var];
                        }
                }
-               $this->sqlMode = $params['sqlMode'] ?? '';
+               $this->sqlMode = $params['sqlMode'] ?? null;
                $this->utf8Mode = !empty( $params['utf8Mode'] );
                $this->insertSelectIsSafe = isset( $params['insertSelectIsSafe'] )
                        ? (bool)$params['insertSelectIsSafe'] : null;