MDEV-19540: 10.4 allow lock options with SELECT in brackets which previous version do not

Check locking options and brackets combinations.

mysql-test/main/parser.result

@@ -1770,3 +1770,18 @@ ERROR HY000: Unknown system variable 'password'
 SELECT @@GLOBAL.role;
 ERROR HY000: Unknown system variable 'role'
 End of 10.3 tests
+#
+# MDEV-19540: 10.4 allow lock options with SELECT in brackets
+# which previous version do not
+#
+create table t1 (a int);
+(select * from t1) for update;
+ERROR HY000: Incorrect usage of lock options and SELECT in brackets
+(select * from t1) union (select * from t1) for update;
+ERROR HY000: Incorrect usage of lock options and SELECT in brackets
+(select * from t1 for update);
+a
+select * from t1 for update;
+a
+drop table t1;
+# End of 10.4 tests

mysql-test/main/parser.test

@@ -1537,3 +1537,19 @@ SELECT @@GLOBAL.password;
 SELECT @@GLOBAL.role;
 
 --echo End of 10.3 tests
+
+--echo #
+--echo # MDEV-19540: 10.4 allow lock options with SELECT in brackets
+--echo # which previous version do not
+--echo #
+
+create table t1 (a int);
+--error ER_WRONG_USAGE
+(select * from t1) for update;
+--error ER_WRONG_USAGE
+(select * from t1) union (select * from t1) for update;
+(select * from t1 for update);
+select * from t1 for update;
+drop table t1;
+
+--echo # End of 10.4 tests

sql/sql_lex.cc

@@ -9246,6 +9246,12 @@ SELECT_LEX_UNIT *LEX::parsed_select_expr_cont(SELECT_LEX_UNIT *unit,
 SELECT_LEX_UNIT *LEX::parsed_body_select(SELECT_LEX *sel,
                                          Lex_order_limit_lock * l)
 {
+  if (sel->braces && l && l->lock.defined_lock)
+  {
+    my_error(ER_WRONG_USAGE, MYF(0), "lock options",
+        "SELECT in brackets");
+    return NULL;
+  }
   if (!(sel= parsed_select(sel, l)))
     return NULL;
 
@@ -9519,7 +9525,7 @@ bool SELECT_LEX_UNIT::set_lock_to_the_last_select(Lex_select_lock l)
     if (sel->braces)
     {
       my_error(ER_WRONG_USAGE, MYF(0), "lock options",
-               "End SELECT expression");
+               "SELECT in brackets");
       return TRUE;
     }
     l.set_to(sel);