plan: check empty table name in RenameTableStmt (#6383)

plan/preprocess.go

@@ -57,6 +57,7 @@ func (p *preprocessor) Enter(in ast.Node) (out ast.Node, skipChildren bool) {
 		p.checkDropTableGrammar(node)
 	case *ast.RenameTableStmt:
 		p.inCreateOrDropTable = true
+		p.checkRenameTableGrammar(node)
 	case *ast.CreateIndexStmt:
 		p.checkCreateIndexGrammar(node)
 	case *ast.AlterTableStmt:
@@ -300,6 +301,21 @@ func (p *preprocessor) checkCreateIndexGrammar(stmt *ast.CreateIndexStmt) {
 	p.err = checkIndexInfo(stmt.IndexName, stmt.IndexColNames)
 }
 
+func (p *preprocessor) checkRenameTableGrammar(stmt *ast.RenameTableStmt) {
+	oldTable := stmt.OldTable.Name.String()
+	newTable := stmt.NewTable.Name.String()
+
+	if isIncorrectName(oldTable) {
+		p.err = ddl.ErrWrongTableName.GenByArgs(oldTable)
+		return
+	}
+
+	if isIncorrectName(newTable) {
+		p.err = ddl.ErrWrongTableName.GenByArgs(newTable)
+		return
+	}
+}
+
 func (p *preprocessor) checkAlterTableGrammar(stmt *ast.AlterTableStmt) {
 	tName := stmt.Table.Name.String()
 	if isIncorrectName(tName) {

plan/preprocess_test.go

@@ -134,6 +134,8 @@ func (s *testValidatorSuite) TestValidator(c *C) {
 		{"alter table t change column a `a ` int", true, errors.New("[ddl:1166]Incorrect column name 'a '")},
 		{"create index idx on `t ` (a)", true, errors.New("[ddl:1103]Incorrect table name 't '")},
 		{"create index idx on  `` (a)", true, errors.New("[ddl:1103]Incorrect table name ''")},
+		{"rename table t to ``", false, errors.New("[ddl:1103]Incorrect table name ''")},
+		{"rename table `` to t", false, errors.New("[ddl:1103]Incorrect table name ''")},
 
 		// issue 3844
 		{`create table t (a set("a, b", "c, d"))`, true, errors.New("[types:1367]Illegal set 'a, b' value found during parsing")},