BUG#26395: if crash during autocommit update to transactional table on master, slave fails

Now, every transaction (including autocommit transactions) start with
a BEGIN and end with a COMMIT/ROLLBACK in the binlog.
Added a test case, and updated lots of test case result files.


mysql-test/t/rpl_transaction-master.opt:
  BitKeeper file /home/sven/bk/b26395-autocommit-xa/5.0-rpl/mysql-test/t/rpl_transaction-master.opt
mysql-test/t/rpl_transaction-slave.opt:
  BitKeeper file /home/sven/bk/b26395-autocommit-xa/5.0-rpl/mysql-test/t/rpl_transaction-slave.opt
mysql-test/r/mix_innodb_myisam_binlog.result:
  Updated result file
mysql-test/r/multi_update.result:
  Updated result file
mysql-test/r/rpl_transaction.result:
  New result file for new test case.
mysql-test/r/sp_trans_log.result:
  Updated result file
mysql-test/r/variables-big.result:
  Updated result file
mysql-test/t/rpl_transaction.test:
  New test case.
sql/log.cc:
   - Always write BEGIN and COMMIT around statements, even in autocommit
     mode.
   - Added comments for binlog_commit and binlog_rollback.
sql/log_event.cc:
  Added debug trigger to avoid writing xid events to the binlog.

mysql-test/t/rpl_transaction-master.opt

@@ -0,0 +1 @@
+--innodb --debug=d,do_not_write_xid

mysql-test/t/rpl_transaction-slave.opt

@@ -0,0 +1 @@
+--innodb

mysql-test/t/rpl_transaction.test

@@ -0,0 +1,106 @@
+# Tests that transactions are replicated correctly, with various
+# combinations of non-transactional and transactional non-XA tables.
+# Also tests that an XA transaction where the master crashes just
+# before writing the XID log event is executed correctly.  See below
+# for implementation details.
+
+# Note: this test should not exist in 5.1 or higher.  It has been
+# replaced by rpl_ndb_transaction.test, which tests a superset of what
+# this test tests.
+
+source include/have_innodb.inc;
+source include/master-slave.inc;
+
+
+CREATE TABLE tmyisam (a int) ENGINE = MYISAM;
+CREATE TABLE tinnodb (a int) ENGINE = INNODB;
+
+SHOW CREATE TABLE tmyisam;
+SHOW CREATE TABLE tinnodb;
+
+
+--echo ==== Test 1: Non-XA Engines ====
+# Test that everything works fine with non-XA engines.  We just try
+# all ways to do transactions involving ndb and/or myisam, with
+# rollback or commit.
+
+--echo --- on master ---
+
+SET AUTOCOMMIT = 1;
+
+INSERT INTO tmyisam VALUES (1);
+
+BEGIN;
+INSERT INTO tmyisam VALUES (2);
+INSERT INTO tmyisam VALUES (3);
+COMMIT;
+
+BEGIN;
+INSERT INTO tmyisam VALUES (5);
+INSERT INTO tmyisam VALUES (6);
+--warning 1196
+ROLLBACK;
+
+SELECT * FROM tmyisam ORDER BY a;
+
+--echo --- on slave ---
+--sync_slave_with_master
+SELECT * FROM tmyisam ORDER BY a;
+
+
+--echo ==== Test 2: Master crash before writing XID event on XA engine ====
+# We now want to test the following scenario, to verify that BUG#26395
+# has been fixed:
+
+#   "master and slave have a transactional table that uses XA. Master
+#    has AUTOCOMMIT on and executes a statement (in this case an
+#    INSERT). Master crashes just before writing the XID event."
+
+# In this scenario, master will roll back, so slave should not execute
+# the statement, and slave should roll back later when master is
+# restarted.
+
+# However, we the master to be alive so that we are sure it replicates
+# the statement to the slave. So in the test case, we must therefore
+# not crash the master. Instead, we fake the crash by just not writing
+# the XID event to the binlog. This is done by the
+# --debug=d,do_not_write_xid flag in the .opt file.
+
+# So, unlike if the master had crashed, the master *will* execute the
+# statement. But the slave should not execute it. Hence, after the
+# first test is executed, the expected result on master is a table
+# with one row, and on slave a table with no rows.
+
+# To simulate the slave correctly, we wait until everything up to the
+# XID is replicated. We cannot sync_slave_with_master, because that
+# would wait for the transaction to end. Instead, we wait for
+# "sufficiently long time". Then we stop the slave.
+
+# Note: since this puts the master binlog in an inconsistent state,
+# this should be the last test of the file.
+
+--echo --- on master ---
+--connection master
+
+INSERT INTO tinnodb VALUES (1);
+SELECT * FROM tinnodb ORDER BY a;
+
+--echo --- on slave ---
+--connection slave
+--sleep 3
+STOP SLAVE;
+source include/wait_for_slave_to_stop.inc;
+--replace_column 4 # 7 # 8 # 9 # 16 # 22 # 23 # 33 #
+query_vertical SHOW SLAVE STATUS;
+# the following statement should show that nothing has been replicated
+SELECT * FROM tinnodb ORDER BY a;
+
+
+# clean up
+connection master;
+DROP TABLE tmyisam;
+DROP TABLE tinnodb;
+
+connection slave;
+DROP TABLE tmyisam;
+DROP TABLE tinnodb;