MDEV-23685 SIGSEGV on ADD FOREIGN KEY after failed ADD KEY

dict_foreign_qualify_index(): Reject corrupted or garbage indexes.
For index stubs that are created on virtual columns, no
dict_field_t::col would be assign. Instead, the entire table
definition would be reloaded on a successful operation.

mysql-test/suite/innodb/r/foreign_key.result

@@ -740,4 +740,15 @@ t2	CREATE TABLE `t2` (
 CREATE TABLE t2 (f1 INT NOT NULL)ENGINE=InnoDB;
 ERROR 42S01: Table 't2' already exists
 DROP TABLE t2, t1;
+#
+# MDEV-23685 SIGSEGV on ADD FOREIGN KEY after failed attempt
+# to create unique key on virtual column
+#
+CREATE TABLE t1 (pk INT PRIMARY KEY, a INT, b INT AS (a)) ENGINE=InnODB;
+INSERT INTO t1 (pk,a) VALUES (1,10),(2,10);
+ALTER TABLE t1 ADD UNIQUE INDEX ind9 (b), LOCK=SHARED;
+ERROR 23000: Duplicate entry '10' for key 'ind9'
+SET FOREIGN_KEY_CHECKS= 0;
+ALTER TABLE t1 ADD FOREIGN KEY (a) REFERENCES t1 (pk);
+DROP TABLE t1;
 # End of 10.2 tests

mysql-test/suite/innodb/t/foreign_key.test

@@ -720,6 +720,19 @@ SHOW CREATE TABLE t2;
 CREATE TABLE t2 (f1 INT NOT NULL)ENGINE=InnoDB;
 DROP TABLE t2, t1;
 
+--echo #
+--echo # MDEV-23685 SIGSEGV on ADD FOREIGN KEY after failed attempt
+--echo # to create unique key on virtual column
+--echo #
+CREATE TABLE t1 (pk INT PRIMARY KEY, a INT, b INT AS (a)) ENGINE=InnODB;
+
+INSERT INTO t1 (pk,a) VALUES (1,10),(2,10);
+--error ER_DUP_ENTRY
+ALTER TABLE t1 ADD UNIQUE INDEX ind9 (b), LOCK=SHARED;
+SET FOREIGN_KEY_CHECKS= 0;
+ALTER TABLE t1 ADD FOREIGN KEY (a) REFERENCES t1 (pk);
+DROP TABLE t1;
+
 --echo # End of 10.2 tests
 
 --source include/wait_until_count_sessions.inc

storage/innobase/dict/dict0dict.cc

@@ -6609,7 +6609,11 @@ dict_foreign_qualify_index(
 		return(false);
 	}
 
-	if (index->type & (DICT_SPATIAL | DICT_FTS)) {
+	if (index->type & (DICT_SPATIAL | DICT_FTS | DICT_CORRUPT)) {
+		return false;
+	}
+
+	if (index->online_status >= ONLINE_INDEX_ABORTED) {
 		return false;
 	}