MDEV-25172 Wrong error message for ADD COLUMN .. AS ROW START

Handle one more condition in fix_alter_info() for non-versioned table
and produce ER_VERS_NOT_VERSIONED error.

mysql-test/suite/versioning/r/alter.result

@@ -80,7 +80,7 @@ t	CREATE TABLE `t` (
   `a` int(11) DEFAULT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 alter table t add column trx_start timestamp(6) as row start;
-ERROR HY000: Duplicate ROW START column `trx_start`
+ERROR HY000: Table `t` is not system-versioned
 alter table t add system versioning;
 show create table t;
 Table	Create Table
@@ -735,3 +735,10 @@ t1	CREATE TABLE `t1` (
 alter table t1 drop column b;
 ERROR 42000: Key column 'b' doesn't exist in table
 drop table t1;
+#
+# MDEV-25172 Wrong error message for ADD COLUMN .. AS ROW START
+#
+create or replace table t1 (x int);
+alter table t1 add column y timestamp(6) as row start;
+ERROR HY000: Table `t1` is not system-versioned
+drop table t1;

mysql-test/suite/versioning/t/alter.test

@@ -68,7 +68,7 @@ select row_start from t;
 alter table t drop system versioning;
 show create table t;
 
---error ER_VERS_DUPLICATE_ROW_START_END
+--error ER_VERS_NOT_VERSIONED
 alter table t add column trx_start timestamp(6) as row start;
 
 alter table t add system versioning;
@@ -621,3 +621,12 @@ alter table t1 drop column b;
 
 # cleanup
 drop table t1;
+
+--echo #
+--echo # MDEV-25172 Wrong error message for ADD COLUMN .. AS ROW START
+--echo #
+create or replace table t1 (x int);
+--error ER_VERS_NOT_VERSIONED
+alter table t1 add column y timestamp(6) as row start;
+# cleanup
+drop table t1;

sql/handler.cc

@@ -7340,6 +7340,11 @@ bool Vers_parse_info::fix_alter_info(THD *thd, Alter_info *alter_info,
     {
       if (f->flags & VERS_SYSTEM_FIELD)
       {
+        if (!table->versioned())
+        {
+          my_error(ER_VERS_NOT_VERSIONED, MYF(0), table->s->table_name.str);
+          return true;
+        }
         my_error(ER_VERS_DUPLICATE_ROW_START_END, MYF(0),
                  f->flags & VERS_SYS_START_FLAG ? "START" : "END", f->field_name.str);
         return true;