MDEV-17573 Assertion in federatedx on multi-update

Cause: shared federatedx_io cannot store table-specific data.

Fix: move current row reference `federatedx_io_mysql::current` to
ha_federatedx.

FederatedX connection (represented by federatedx_io) is stored into
federatedx_txn::txn_list of per-server connections (see
federatedx_txn::acquire()). federatedx_txn object is stored into THD
(see ha_federatedx::external_lock()). When multiple handlers acquire
FederatedX connection they get single federatedx_io instance. Multiple
handlers do their operation via federatedx_io_mysql::mark_position()
and federatedx_io_mysql::fetch_row() in arbitrarty manner. They access
the same federatedx_io_mysql instance and same MYSQL_ROWS *current
pointer, so one handler disrupts the work of the other.

Related to "MDEV-14551 Can't find record in table on multi-table update
with ORDER BY".

2 files changed, 55 insertions, 0 deletions

diff --git a/mysql-test/suite/federated/federatedx.result b/mysql-test/suite/federated/federatedx.result
index 84dcb0d0a8c..af01bb3d90f 100644
--- a/mysql-test/suite/federated/federatedx.result
+++ b/mysql-test/suite/federated/federatedx.result
@@ -2283,6 +2283,32 @@ connection default;
 connection master;
 CREATE TABLE t1 (a INT) ENGINE=FEDERATED CONNECTION='mysql://@127.0.0.1:SLAVE_PORT/federated/t1';
 ERROR HY000: Can't create federated table. Foreign data src error:  database: 'federated'  username: ''  hostname: '127.0.0.1'
+#
+# MDEV-17573 Assertion in federatedx on multi-update
+#
+create table t1 (
+x int,
+d datetime);
+create table t1f engine=FEDERATED connection='mysql://root@127.0.0.1:MASTER_MYPORT/test/t1';
+create table t2 (
+x int, y int,
+d datetime);
+create table t2f engine=FEDERATED connection='mysql://root@127.0.0.1:MASTER_MYPORT/test/t2';
+create table t3 (
+x int, y int, z int,
+d datetime);
+create table t3f engine=FEDERATED connection='mysql://root@127.0.0.1:MASTER_MYPORT/test/t3';
+insert into t1 values (1, "1990-01-01 00:00");
+insert into t1 values (1, "1991-01-01 11:11");
+insert into t2 values (2, 2, "1992-02-02 22:22");
+insert into t3 values (3, 3, 3, "1993-03-03 23:33");
+update t1f, t2f, t3f set t1f.x= 11, t2f.y= 22, t3f.z= 33;
+drop table t1f;
+drop table t2f;
+drop table t3f;
+drop table t1;
+drop table t2;
+drop table t3;
 connection master;
 DROP TABLE IF EXISTS federated.t1;
 DROP DATABASE IF EXISTS federated;
diff --git a/mysql-test/suite/federated/federatedx.test b/mysql-test/suite/federated/federatedx.test
index 29d1eaddc26..bd03f744639 100644
--- a/mysql-test/suite/federated/federatedx.test
+++ b/mysql-test/suite/federated/federatedx.test
@@ -2010,4 +2010,33 @@ connection master;
 --error ER_CANT_CREATE_FEDERATED_TABLE
 eval CREATE TABLE t1 (a INT) ENGINE=FEDERATED CONNECTION='mysql://@127.0.0.1:$SLAVE_MYPORT/federated/t1';
 
+--echo #
+--echo # MDEV-17573 Assertion in federatedx on multi-update
+--echo #
+create table t1 (
+  x int,
+  d datetime);
+--replace_result $MASTER_MYPORT MASTER_MYPORT
+eval create table t1f engine=FEDERATED connection='mysql://root@127.0.0.1:$MASTER_MYPORT/test/t1';
+
+create table t2 (
+  x int, y int,
+  d datetime);
+--replace_result $MASTER_MYPORT MASTER_MYPORT
+eval create table t2f engine=FEDERATED connection='mysql://root@127.0.0.1:$MASTER_MYPORT/test/t2';
+
+create table t3 (
+  x int, y int, z int,
+  d datetime);
+--replace_result $MASTER_MYPORT MASTER_MYPORT
+eval create table t3f engine=FEDERATED connection='mysql://root@127.0.0.1:$MASTER_MYPORT/test/t3';
+
+insert into t1 values (1, "1990-01-01 00:00");
+insert into t1 values (1, "1991-01-01 11:11");
+insert into t2 values (2, 2, "1992-02-02 22:22");
+insert into t3 values (3, 3, 3, "1993-03-03 23:33");
+update t1f, t2f, t3f set t1f.x= 11, t2f.y= 22, t3f.z= 33;
+
+drop table t1f; drop table t2f; drop table t3f; drop table t1; drop table t2; drop table t3;
+
 source include/federated_cleanup.inc;