Merge with MySQL 5.1, with following additions:

- Moved some code from innodb_plugin to xtradb, to ensure that all tests runs
- Did changes in pbxt and maria storage engines becasue of changes in thd->query
- Reverted wrong code in sql_table.cc for how ROW_FORMAT is used.

Todo before joining with main 5.1 tree:
- Join test fails (Igor to investigate)
- mysql-test-run shows warnings from tests; Some suppression rule is not working (Kristian to investiage)
- Run through all buildbots



sql/sql_table.cc:
  Reverted code for ROW_FORMAT is used. We must set the HA_CREATE_USED_ROW_FORMAT flag in alter table
  to signal the handler that it should not change row_type in update_create_info() (as happens for SHOW CREATE).
storage/maria/ha_maria.cc:
  Update for change in defintion of thd->query
storage/myisam/mi_check.c:
  Simplify code
storage/pbxt/src/discover_xt.cc:
  Update for change in defintion of thd->query
storage/xtradb/dict/dict0dict.c:
  Update for change in defintion of thd->query
storage/xtradb/handler/ha_innodb.cc:
  Copy some critical changes from innodb_plugin to get tests to pass
storage/xtradb/handler/ha_innodb.h:
  Copy some critical changes from innodb_plugin to get tests to pass
storage/xtradb/handler/handler0alter.cc:
  Copy some critical changes from innodb_plugin to get tests to pass

mysql-test/suite/federated/federated_debug-master.opt

@@ -0,0 +1 @@
+--loose-debug=d,simulate_detached_thread_refresh

mysql-test/suite/federated/federated_debug.result

@@ -0,0 +1,33 @@
+CREATE DATABASE federated;
+CREATE DATABASE federated;
+#
+# Bug#47525: MySQL crashed (Federated)
+#
+# Switch to slave
+CREATE TABLE t1(a INT);
+INSERT INTO t1 VALUES (1);
+# Switch to master
+CREATE TABLE t1(a INT) ENGINE=FEDERATED
+CONNECTION='mysql://root@127.0.0.1:SLAVE_PORT/test/t1';
+SELECT * FROM t1;
+a
+1
+# Start a asynchronous reload
+# Wait for tables to be closed
+# Timeout in include/wait_show_condition.inc for 
+#         show_statement : SHOW STATUS LIKE 'Open_tables'
+#         field          : Value
+#         condition      : = '0'
+#         max_run_time   : 31
+# Ensure that the server didn't crash
+SELECT * FROM t1;
+a
+1
+# Drop tables on master and slave
+DROP TABLE t1;
+DROP TABLE t1;
+# Federated cleanup
+DROP TABLE IF EXISTS federated.t1;
+DROP DATABASE IF EXISTS federated;
+DROP TABLE IF EXISTS federated.t1;
+DROP DATABASE IF EXISTS federated;

mysql-test/suite/federated/federated_debug.test

@@ -0,0 +1,39 @@
+--source include/have_debug.inc
+--source federated.inc
+
+--echo #
+--echo # Bug#47525: MySQL crashed (Federated)
+--echo #
+
+connection slave;
+--echo # Switch to slave
+CREATE TABLE t1(a INT);
+INSERT INTO t1 VALUES (1);
+
+connection master;
+--echo # Switch to master
+--replace_result $SLAVE_MYPORT SLAVE_PORT
+eval CREATE TABLE t1(a INT) ENGINE=FEDERATED
+  CONNECTION='mysql://root@127.0.0.1:$SLAVE_MYPORT/test/t1';
+
+SELECT * FROM t1;
+
+--echo # Start a asynchronous reload
+--exec $MYSQLADMIN --no-defaults -S $MASTER_MYSOCK -P $MASTER_MYPORT  -u root --password= refresh 2>&1
+
+--echo # Wait for tables to be closed
+let $show_statement= SHOW STATUS LIKE 'Open_tables';
+let $field= Value;
+let $condition= = '0';
+--source include/wait_show_condition.inc
+
+--echo # Ensure that the server didn't crash
+SELECT * FROM t1;
+--echo # Drop tables on master and slave
+DROP TABLE t1;
+connection slave;
+DROP TABLE t1;
+
+connection default;
+--echo # Federated cleanup
+source federated_cleanup.inc;

mysql-test/suite/federated/my.cnf

@@ -9,4 +9,7 @@ log-bin=                 master-bin
 
 [ENV]
 MASTER_MYPORT=           @mysqld.1.port
+MASTER_MYSOCK=           @mysqld.1.socket
+
 SLAVE_MYPORT=            @mysqld.2.port
+SLAVE_MYSOCK=            @mysqld.2.socket