MDEV-28706 Redundant InnoDB table fails during alter

- Redundant InnoDB table fails to set the flags2 while loading
the table. It leads to "Upgrade index name failure" during alter
operation. InnoDB should set the flags2 to FTS_AUX_HEX_NAME when
fts is being loaded

mysql-test/suite/innodb_fts/r/crash_recovery.result

@@ -134,3 +134,15 @@ id	title	body
 1	MySQL Tutorial	DBMS stands for Database...
 2	MariaDB Tutorial	DB means Database ...
 DROP TABLE mdev19073, mdev19073_2;
+#
+# MDEV-28706  Redundant InnoDB table fails during alter
+#
+SET @@global.innodb_file_per_table = 0;
+CREATE TABLE t1 (
+col_int INTEGER, col_text TEXT,
+col_text_1 TEXT
+) ENGINE = InnoDB ROW_FORMAT = Redundant ;
+ALTER TABLE t1 ADD FULLTEXT KEY `ftidx` ( col_text ) ;
+INSERT INTO t1 VALUES ( 1255, "mariadb", "InnoDB");
+ALTER TABLE t1 ADD FULLTEXT(col_text_1);
+DROP TABLE t1;

mysql-test/suite/innodb_fts/t/crash_recovery.test

@@ -193,3 +193,18 @@ AGAINST ('Database' IN NATURAL LANGUAGE MODE);
 SELECT * FROM mdev19073_2 WHERE MATCH (title, body)
 AGAINST ('Database' IN NATURAL LANGUAGE MODE);
 DROP TABLE mdev19073, mdev19073_2;
+
+--echo #
+--echo # MDEV-28706  Redundant InnoDB table fails during alter
+--echo #
+
+SET @@global.innodb_file_per_table = 0;
+CREATE TABLE t1 (
+   col_int INTEGER, col_text TEXT,
+   col_text_1 TEXT
+) ENGINE = InnoDB ROW_FORMAT = Redundant ;
+ALTER TABLE t1 ADD FULLTEXT KEY `ftidx` ( col_text ) ;
+INSERT INTO t1 VALUES ( 1255, "mariadb", "InnoDB");
+--source include/restart_mysqld.inc
+ALTER TABLE t1 ADD FULLTEXT(col_text_1);
+DROP TABLE t1;

storage/innobase/dict/dict0load.cc

@@ -1852,6 +1852,7 @@ dict_load_columns(
 			if (table->fts == NULL) {
 				table->fts = fts_create(table);
 				table->fts->cache = fts_cache_create(table);
+				DICT_TF2_FLAG_SET(table, DICT_TF2_FTS_AUX_HEX_NAME);
 				fts_optimize_add_table(table);
 			}