diff --git a/storage/spider/mysql-test/spider/bugfix/r/mdev_29963.result b/storage/spider/mysql-test/spider/bugfix/r/mdev_29963.result
new file mode 100644
index 00000000000..17390346a99
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/r/mdev_29963.result
@@ -0,0 +1,43 @@
+#
+# MDEV-29963 SIGSEGV in spider_db_mbase::append_lock_tables on LOCK TABLES
+#
+for master_1
+for child2
+for child3
+CREATE SERVER srv FOREIGN DATA WRAPPER mysql
+OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
+CREATE TABLE t (a INT) ENGINE=Spider;
+CREATE TABLE t2 (b INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+LOCK TABLES t AS a READ,t2 AS b LOW_PRIORITY WRITE,t2 AS c WRITE;
+ERROR HY000: Unable to connect to foreign data source: localhost
+DROP TABLE t2;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+LOCK TABLES t2 WRITE;
+ERROR HY000: Unable to connect to foreign data source: localhost
+DROP TABLE t2,t;
+CREATE TABLE t (a INT);
+CREATE TABLE t1 (a INT) ENGINE=Spider;
+CREATE TABLE t2 (b INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+LOCK TABLES t1 READ, t2 WRITE;
+ERROR HY000: Unable to connect to foreign data source: localhost
+DROP TABLE t2;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+LOCK TABLES t2 WRITE;
+UNLOCK TABLES;
+DROP TABLE t, t1, t2;
+CREATE TABLE t1 (c INT) ENGINE=Spider;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT="WRAPPER 'mysql',srv 'srv',TABLE 't1'";
+LOCK TABLES t1 WRITE,t2 WRITE;
+ERROR HY000: Unable to connect to foreign data source: localhost
+TRUNCATE t2;
+ERROR HY000: Unable to connect to foreign data source: localhost
+LOCK TABLES t2 AS o WRITE;
+ERROR HY000: Unable to connect to foreign data source: localhost
+drop table t1, t2;
+drop server srv;
+for master_1
+for child2
+for child3
+#
+# end of test mdev_29963
+#
diff --git a/storage/spider/mysql-test/spider/bugfix/t/mdev_29963.test b/storage/spider/mysql-test/spider/bugfix/t/mdev_29963.test
new file mode 100644
index 00000000000..ab7a4ded07c
--- /dev/null
+++ b/storage/spider/mysql-test/spider/bugfix/t/mdev_29963.test
@@ -0,0 +1,55 @@
+--echo #
+--echo # MDEV-29963 SIGSEGV in spider_db_mbase::append_lock_tables on LOCK TABLES
+--echo #
+--disable_query_log
+--disable_result_log
+--source ../../t/test_init.inc
+--enable_result_log
+--enable_query_log
+
+evalp CREATE SERVER srv FOREIGN DATA WRAPPER mysql
+OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');
+
+CREATE TABLE t (a INT) ENGINE=Spider;
+CREATE TABLE t2 (b INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLES t AS a READ,t2 AS b LOW_PRIORITY WRITE,t2 AS c WRITE;
+DROP TABLE t2;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLES t2 WRITE;
+DROP TABLE t2,t;
+
+# A less complex scenario
+CREATE TABLE t (a INT);
+CREATE TABLE t1 (a INT) ENGINE=Spider;
+CREATE TABLE t2 (b INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLES t1 READ, t2 WRITE;
+DROP TABLE t2;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",srv "srv",TABLE "t"';
+LOCK TABLES t2 WRITE;
+UNLOCK TABLES;
+DROP TABLE t, t1, t2;
+
+# MDEV-31357
+CREATE TABLE t1 (c INT) ENGINE=Spider;
+CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT="WRAPPER 'mysql',srv 'srv',TABLE 't1'";
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLES t1 WRITE,t2 WRITE;
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+TRUNCATE t2;
+--error ER_CONNECT_TO_FOREIGN_DATA_SOURCE
+LOCK TABLES t2 AS o WRITE;
+drop table t1, t2;
+
+drop server srv;
+
+--disable_query_log
+--disable_result_log
+--source ../../t/test_deinit.inc
+--enable_result_log
+--enable_query_log
+--echo #
+--echo # end of test mdev_29963
+--echo #
diff --git a/storage/spider/spd_trx.cc b/storage/spider/spd_trx.cc
index 311c78ccb5c..cfdbedee069 100644
--- a/storage/spider/spd_trx.cc
+++ b/storage/spider/spd_trx.cc
@@ -3462,6 +3462,14 @@ int spider_rollback(
   trx->bulk_access_conn_first = NULL;
 #endif
 
+  /* In case the rollback happens due to failure of LOCK TABLE, we
+  need to clear the list of tables to lock. */
+  for (uint i= 0; i < trx->trx_conn_hash.records; i++)
+  {
+    conn= (SPIDER_CONN *) my_hash_element(&trx->trx_conn_hash, i);
+    conn->db_conn->reset_lock_table_hash();
+  }
+
   if (all || (!thd_test_options(thd, OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN)))
   {
     if (trx->trx_start)