MDEV-24403 Segfault on CREATE TABLE with explicit FTS_DOC_ID_INDEX by multiple fields

Ignore table->fts freed previously by create_table_info_t::create_table().

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

@@ -182,3 +182,13 @@ Table	Op	Msg_type	Msg_text
 test.t1	optimize	status	OK
 DROP TABLE t1;
 SET GLOBAL innodb_optimize_fulltext_only= @optimize_fulltext.save;
+#
+# MDEV-24403 Segfault on CREATE TABLE with explicit FTS_DOC_ID_INDEX by multiple fields
+#
+create table t1 (
+f1 int, f2 text,
+FTS_DOC_ID bigint unsigned not null,
+unique key FTS_DOC_ID_INDEX(FTS_DOC_ID, f1),
+fulltext (f2))
+engine=innodb;
+ERROR 42000: Incorrect index name 'FTS_DOC_ID_INDEX'

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

@@ -106,3 +106,14 @@ SET GLOBAL innodb_optimize_fulltext_only= 1;
 OPTIMIZE TABLE t1;
 DROP TABLE t1;
 SET GLOBAL innodb_optimize_fulltext_only= @optimize_fulltext.save;
+
+--echo #
+--echo # MDEV-24403 Segfault on CREATE TABLE with explicit FTS_DOC_ID_INDEX by multiple fields
+--echo #
+--error ER_WRONG_NAME_FOR_INDEX
+create table t1 (
+  f1 int, f2 text,
+  FTS_DOC_ID bigint unsigned not null,
+  unique key FTS_DOC_ID_INDEX(FTS_DOC_ID, f1),
+  fulltext (f2))
+engine=innodb;

storage/innobase/fts/fts0fts.cc

@@ -1709,7 +1709,7 @@ fts_drop_tables(
 
 	error = fts_drop_common_tables(trx, &fts_table);
 
-	if (error == DB_SUCCESS) {
+	if (error == DB_SUCCESS && table->fts) {
 		error = fts_drop_all_index_tables(trx, table->fts);
 	}