Merge pull request #11981 from eiselems:1.5.xMysqlValidationQuery

* pr/11981:
  Update MySQL validation query to use lightweight ping
  Polish
  Reinject mocks when context is dirtied before each method
  Polish “Prevent reverse name lookup when configuring Jetty's address”
  Prevent reverse name lookup when configuring Jetty's address
  Fixup version numbers following release
  Next Development Version
  Protect against symlink attacks
  All CLI support for Windows MINGW environments
  Polish

spring-boot/src/main/java/org/springframework/boot/jdbc/DatabaseDriver.java

@@ -67,7 +67,7 @@ public enum DatabaseDriver {
 	 * MySQL.
 	 */
 	MYSQL("MySQL", "com.mysql.jdbc.Driver",
-			"com.mysql.jdbc.jdbc2.optional.MysqlXADataSource", "SELECT 1"),
+			"com.mysql.jdbc.jdbc2.optional.MysqlXADataSource", "/* ping */ SELECT 1"),
 
 	/**
 	 * Maria DB.