From d1fca0baab272bd4d24b22dd6fa565703eee03ca Mon Sep 17 00:00:00 2001
From: Thirunarayanan Balathandayuthapani <thiru@mariadb.com>
Date: Fri, 1 Sep 2023 17:42:47 +0530
Subject: [PATCH] MDEV-32060  Server aborts when table doesn't have referenced
 index

- Server aborts when table doesn't have referenced index.
This is caused by 5f09b53bdb4e973e7c7ec2c53a24c98321223f98 (MDEV-31086).
While iterating the foreign key constraints, we fail to
consider that InnoDB doesn't have referenced index for
it when foreign key check is disabled.
---
 mysql-test/suite/innodb/r/fk_col_alter.result | 13 +++++++++++++
 mysql-test/suite/innodb/t/fk_col_alter.test   | 15 +++++++++++++++
 storage/innobase/handler/handler0alter.cc     |  2 ++
 3 files changed, 30 insertions(+)

diff --git a/mysql-test/suite/innodb/r/fk_col_alter.result b/mysql-test/suite/innodb/r/fk_col_alter.result
index a6888943523..a220402db94 100644
--- a/mysql-test/suite/innodb/r/fk_col_alter.result
+++ b/mysql-test/suite/innodb/r/fk_col_alter.result
@@ -81,4 +81,17 @@ DROP TABLE t2, t1;
 CREATE TABLE t (a VARCHAR(40), b INT, C INT) ENGINE=InnoDB;
 ALTER TABLE t MODIFY a VARCHAR(50), DROP b;
 DROP TABLE t;
+#
+#  MDEV-32060 Server aborts when table doesn't
+#		have referenced index
+#
+SET SESSION FOREIGN_KEY_CHECKS = OFF;
+CREATE TABLE t1 (a VARCHAR(16) KEY, FOREIGN KEY(a) REFERENCES t2(b)) ENGINE=InnoDB;
+CREATE TABLE t2 (b VARCHAR(8)) ENGINE=InnoDB;
+ERROR HY000: Can't create table `test`.`t2` (errno: 150 "Foreign key constraint is incorrectly formed")
+SET SESSION FOREIGN_KEY_CHECKS = ON;
+ALTER TABLE t2 MODIFY b VARCHAR(16), ADD KEY(b);
+ERROR 42S02: Table 'test.t2' doesn't exist
+DROP TABLE t2, t1;
+ERROR 42S02: Unknown table 'test.t2'
 # End of 10.4 tests
diff --git a/mysql-test/suite/innodb/t/fk_col_alter.test b/mysql-test/suite/innodb/t/fk_col_alter.test
index 169210e12c1..87ccde5652a 100644
--- a/mysql-test/suite/innodb/t/fk_col_alter.test
+++ b/mysql-test/suite/innodb/t/fk_col_alter.test
@@ -111,4 +111,19 @@ DROP TABLE t2, t1;
 CREATE TABLE t (a VARCHAR(40), b INT, C INT) ENGINE=InnoDB;
 ALTER TABLE t MODIFY a VARCHAR(50), DROP b;
 DROP TABLE t;
+
+--echo #
+--echo #  MDEV-32060 Server aborts when table doesn't
+--echo #		have referenced index
+--echo #
+SET SESSION FOREIGN_KEY_CHECKS = OFF;
+CREATE TABLE t1 (a VARCHAR(16) KEY, FOREIGN KEY(a) REFERENCES t2(b)) ENGINE=InnoDB;
+# Following SQL is allowed in 10.6
+--error ER_CANT_CREATE_TABLE
+CREATE TABLE t2 (b VARCHAR(8)) ENGINE=InnoDB;
+SET SESSION FOREIGN_KEY_CHECKS = ON;
+--error ER_NO_SUCH_TABLE
+ALTER TABLE t2 MODIFY b VARCHAR(16), ADD KEY(b);
+--error ER_BAD_TABLE_ERROR
+DROP TABLE t2, t1;
 --echo # End of 10.4 tests
diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc
index a5ccb1957f3..bde3c1fb05e 100644
--- a/storage/innobase/handler/handler0alter.cc
+++ b/storage/innobase/handler/handler0alter.cc
@@ -7712,6 +7712,8 @@ next_item:
   {
     for (ulint i= 0; i < f->n_fields; i++)
     {
+      if (!f->referenced_index)
+        continue;
       if (f->referenced_index->fields[i].col == col)
       {
         my_error(ER_FK_COLUMN_CANNOT_CHANGE_CHILD, MYF(0),