MDEV-19647 Server hangs after dropping full text indexes and restart

- There is no need to add the table in fts_optimize_wq if there is
no fts indexes associated with it.

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

@@ -734,15 +734,21 @@ count(*)
 DROP TABLE t1;
 "----------Test27---------"
 CREATE TABLE t1 (id INT,char_column VARCHAR(60));
+CREATE TABLE t2 (FTS_DOC_ID BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, a TEXT)ENGINE=InnoDB;
+ALTER TABLE t2 DROP a;
 SET @@autocommit=0;
 CREATE FULLTEXT INDEX i ON t1 (char_column);
 INSERT INTO t1 values (1,'aaa');
 "restart server..."
-# Restart the server
---source include/restart_mysqld.inc
-DELETE FROM t1 WHERE MATCH(char_column) AGAINST ('bbb')
+SHOW CREATE TABLE t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `FTS_DOC_ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+  PRIMARY KEY (`FTS_DOC_ID`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+DELETE FROM t1 WHERE MATCH(char_column) AGAINST ('bbb');
 SET @@autocommit=1;
-DROP TABLE t1;
+DROP TABLE t1, t2;
 "----------Test28---------"
 drop table if exists `fts_test`;
 Warnings:

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

@@ -667,15 +667,18 @@ DROP TABLE t1;
 --echo "----------Test27---------"
 #27 Crash after server restart
 CREATE TABLE t1 (id INT,char_column VARCHAR(60));
+CREATE TABLE t2 (FTS_DOC_ID BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, a TEXT)ENGINE=InnoDB;
+ALTER TABLE t2 DROP a;
 SET @@autocommit=0;
 CREATE FULLTEXT INDEX i ON t1 (char_column);
 INSERT INTO t1 values (1,'aaa');
-echo "restart server..."
+echo "restart server...";
 # Restart the server
 --source include/restart_mysqld.inc
+SHOW CREATE TABLE t2;
 DELETE FROM t1 WHERE MATCH(char_column) AGAINST ('bbb');
 SET @@autocommit=1;
-DROP TABLE t1;
+DROP TABLE t1, t2;
 
 --echo "----------Test28---------"
 drop table if exists `fts_test`;

storage/innobase/fts/fts0opt.cc

@@ -2614,6 +2614,12 @@ UNIV_INTERN void fts_optimize_add_table(dict_table_t* table)
 		return;
 	}
 
+	/* If there is no fts index present then don't add to
+	optimize queue. */
+	if (!ib_vector_size(table->fts->indexes)) {
+		return;
+	}
+
 	/* Make sure table with FTS index cannot be evicted */
 	if (table->can_be_evicted) {
 		dict_table_move_from_lru_to_non_lru(table);

storage/xtradb/fts/fts0opt.cc

@@ -2614,6 +2614,12 @@ UNIV_INTERN void fts_optimize_add_table(dict_table_t* table)
 		return;
 	}
 
+	/* If there is no fts index present then don't add to
+	optimize queue. */
+	if (!ib_vector_size(table->fts->indexes)) {
+		return;
+	}
+
 	/* Make sure table with FTS index cannot be evicted */
 	if (table->can_be_evicted) {
 		dict_table_move_from_lru_to_non_lru(table);