Statistics are lost after ALTER TABLE

 @@ -11189,44 +11237,19 @@ ha_innobase::commit_inplace_alter_table(

 	Currently dict_load_column_low() is the only place where

 	num_base for virtual columns is assigned to nonzero. */

 	if (ctx0->num_to_drop_vcol || ctx0->num_to_add_vcol

+	    || (ctx0->new_table->n_v_cols && !new_clustered

+		&& (ha_alter_info->alter_info->drop_list.elements

+		    || ha_alter_info->alter_info->create_list.elements))

 	    || (ctx0->is_instant()

 		&& m_prebuilt->table->n_v_cols

 		&& ha_alter_info->handler_flags & ALTER_STORED_COLUMN_ORDER)) {

...

CURRENT_TEST: gcol.innodb_virtual_stats

--- /mariadb/10.5m/mysql-test/suite/gcol/r/innodb_virtual_stats.result	2020-11-18 08:34:35.136411687 +0200

+++ /mariadb/10.5m/mysql-test/suite/gcol/r/innodb_virtual_stats.reject	2021-01-11 12:57:24.756571844 +0200

@@ -121,19 +121,4 @@

 FROM mysql.innodb_index_stats

 WHERE database_name = 'test' AND table_name = 't';

 index_name	stat_name	stat_description

-GEN_CLUST_INDEX	n_diff_pfx01	DB_ROW_ID

-GEN_CLUST_INDEX	n_leaf_pages	Number of leaf pages in the index

-GEN_CLUST_INDEX	size	Number of pages in the index

-idxb	n_diff_pfx01	b

-idxb	n_diff_pfx02	b,DB_ROW_ID

-idxb	n_leaf_pages	Number of leaf pages in the index

-idxb	size	Number of pages in the index

-vidxe	n_diff_pfx01	e

-vidxe	n_diff_pfx02	e,DB_ROW_ID

-vidxe	n_leaf_pages	Number of leaf pages in the index

-vidxe	size	Number of pages in the index

-vidxf	n_diff_pfx01	f

-vidxf	n_diff_pfx02	f,DB_ROW_ID

-vidxf	n_leaf_pages	Number of leaf pages in the index

-vidxf	size	Number of pages in the index

 DROP TABLE t;

mysqltest: Result length mismatch

ALTER TABLE t DROP INDEX vidxcd;

	if (ib_table->is_readable()) {

		dict_stats_init(ib_table);

	} else {

		ib_table->stat_initialized = 1;

	}