config: always skip the system databases

lightning/config/config.go

@@ -198,6 +198,7 @@ func NewConfig() *Config {
 		PostRestore: PostRestore{
 			Checksum: true,
 		},
+		BWList: &filter.Rules{},
 	}
 }
 
@@ -318,6 +319,13 @@ func (cfg *Config) Adjust() error {
 		return errors.Annotate(err, "invalid config: `mydumper.tidb.sql_mode` must be a valid SQL_MODE")
 	}
 
+	cfg.BWList.IgnoreDBs = append(cfg.BWList.IgnoreDBs,
+		"mysql",
+		"information_schema",
+		"performance_schema",
+		"sys",
+	)
+
 	for _, rule := range cfg.Routes {
 		if !cfg.Mydumper.CaseSensitive {
 			rule.ToLower()

tests/black-white-list/data/mysql-schema-create.sql

@@ -0,0 +1 @@
+create database mysql;

tests/black-white-list/data/mysql.testtable-schema.sql

@@ -0,0 +1 @@
+create table `testtable` (a int primary key);

tests/black-white-list/run.sh

@@ -26,6 +26,8 @@ check_not_contains 'Database: seconddb'
 run_sql 'SHOW TABLES IN firstdb;'
 check_contains 'Tables_in_firstdb: first'
 check_contains 'Tables_in_firstdb: second'
+run_sql 'SHOW TABLES IN mysql;'
+check_not_contains 'Tables_in_mysql: testtable'
 
 run_sql 'DROP DATABASE IF EXISTS firstdb;'
 run_sql 'DROP DATABASE IF EXISTS seconddb;'
@@ -39,3 +41,5 @@ check_contains 'Tables_in_firstdb: second'
 run_sql 'SHOW TABLES IN seconddb;'
 check_not_contains 'Tables_in_seconddb: third'
 check_contains 'Tables_in_seconddb: fourth'
+run_sql 'SHOW TABLES IN mysql;'
+check_not_contains 'Tables_in_mysql: testtable'