MDEV-18967 Load data in system version with long unique does not work

Update system versioning fields before generated columns for left out
fill_record

mysql-test/main/long_unique_bugs.result

@@ -186,3 +186,12 @@ c varchar(5000),
 UNIQUE(c,b(64))
 ) ENGINE=InnoDB;
 drop table t1;
+CREATE TABLE t1 (data VARCHAR(4), unique(data) using hash) with system versioning;
+INSERT INTO t1 VALUES ('A');
+SELECT * INTO OUTFILE 'load.data' from t1;
+LOAD DATA INFILE 'load.data'  INTO TABLE t1;
+ERROR 23000: Duplicate entry 'A' for key 'data'
+select * from t1;
+data
+A
+DROP TABLE t1;

mysql-test/main/long_unique_bugs.test

@@ -215,3 +215,16 @@ CREATE TABLE t1 (
   UNIQUE(c,b(64))
 ) ENGINE=InnoDB;
 drop table t1;
+
+#
+# MDEV-18967 Load data in system version with long unique does not work
+#
+CREATE TABLE t1 (data VARCHAR(4), unique(data) using hash) with system versioning;
+INSERT INTO t1 VALUES ('A');
+SELECT * INTO OUTFILE 'load.data' from t1;
+--error ER_DUP_ENTRY
+LOAD DATA INFILE 'load.data'  INTO TABLE t1;
+select * from t1;
+DROP TABLE t1;
+--let $datadir= `select @@datadir`
+--remove_file $datadir/test/load.data

sql/sql_base.cc

@@ -8439,12 +8439,12 @@ fill_record(THD *thd, TABLE *table_arg, List<Item> &fields, List<Item> &values,
   if (!update && table_arg->default_field &&
       table_arg->update_default_fields(0, ignore_errors))
     goto err;
+  if (table_arg->versioned() && !only_unvers_fields)
+    table_arg->vers_update_fields();
   /* Update virtual fields */
   if (table_arg->vfield &&
       table_arg->update_virtual_fields(table_arg->file, VCOL_UPDATE_FOR_WRITE))
     goto err;
-  if (table_arg->versioned() && !only_unvers_fields)
-    table_arg->vers_update_fields();
   thd->abort_on_warning= save_abort_on_warning;
   thd->no_errors=        save_no_errors;
   DBUG_RETURN(thd->is_error());