BUG#17654 : --read-from-remote-server causes core

This patch corrects a problem encountered when reading the binlog from a remote
host. The application was crashing because the buffer variable (temp_buf) in 
log_event was not pointing to the incoming data. For a normal file read, this 
buffer is allocated by a previous call of read_log_event. However, when reading
from a remote host, the first call to read_log_event is not executed therefore
no buffer is allocated. Furthermore, there is no need to allocate a new buffer 
because the incoming stream is what needs to be read. 

This patch adds the call to initialize the temp_buf variable if reading from a 
remote host. It also adds a check at destroy time to ensure the temp_buf is not
freed if reading from a remote host.

client/mysqlbinlog.cc

@@ -682,8 +682,16 @@ Begin_load_query event for file_id: %u\n", exlq->file_id);
 
 end:
   rec_count++;
+  /*
+    Destroy the log_event object. If reading from a remote host,
+    set the temp_buf to NULL so that memory isn't freed twice.
+  */
   if (ev)
+  {
+    if (remote_opt)
+      ev->temp_buf= 0;
     delete ev;
+  }
   DBUG_RETURN(0);
 }
 
@@ -1172,6 +1180,12 @@ could be out of memory");
       error= 1;
       goto err;
     }   
+    /*
+      If reading from a remote host, ensure the temp_buf for the
+      Log_event class is pointing to the incoming stream.
+    */
+    if (remote_opt)
+      ev->register_temp_buf((char*) net->read_pos + 1); 
 
     Log_event_type type= ev->get_type_code();
     if (glob_description_event->binlog_version >= 3 ||

mysql-test/r/rpl_row_mysqlbinlog.result

@@ -190,6 +190,75 @@ DELIMITER ;
 ROLLBACK /* added by mysqlbinlog */;
 /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
 
+--- Test 4 Second Remote test --
+DROP TABLE t1;
+DROP TABLE t2;
+DROP TABLE t3;
+stop slave;
+reset master;
+reset slave;
+start slave;
+SELECT COUNT(*) from t1;
+COUNT(*)
+352
+SELECT COUNT(*) from t2;
+COUNT(*)
+500
+SELECT COUNT(*) from t3;
+COUNT(*)
+500
+SELECT * FROM t1 ORDER BY word LIMIT 5;
+word
+Aarhus
+Aarhus
+Aarhus
+Aarhus
+Aarhus
+SELECT * FROM t2 ORDER BY id LIMIT 5;
+id
+1
+2
+3
+4
+5
+SELECT c1, c3, c4, c5  FROM t3 ORDER BY c1 LIMIT 5;
+c1	c3	c4	c5
+1	2006-02-22 00:00:00	Tested in Texas	2.2
+2	2006-02-22 00:00:00	Tested in Texas	4.4
+3	2006-02-22 00:00:00	Tested in Texas	6.6
+4	2006-02-22 00:00:00	Tested in Texas	8.8
+5	2006-02-22 00:00:00	Tested in Texas	11
+SELECT COUNT(*) from t1;
+COUNT(*)
+352
+SELECT COUNT(*) from t2;
+COUNT(*)
+500
+SELECT COUNT(*) from t3;
+COUNT(*)
+500
+SELECT * FROM t1 ORDER BY word LIMIT 5;
+word
+Aarhus
+Aarhus
+Aarhus
+Aarhus
+Aarhus
+SELECT * FROM t2 ORDER BY id LIMIT 5;
+id
+1
+2
+3
+4
+5
+SELECT c1, c3, c4, c5  FROM t3 ORDER BY c1 LIMIT 5;
+c1	c3	c4	c5
+1	2006-02-22 00:00:00	Tested in Texas	2.2
+2	2006-02-22 00:00:00	Tested in Texas	4.4
+3	2006-02-22 00:00:00	Tested in Texas	6.6
+4	2006-02-22 00:00:00	Tested in Texas	8.8
+5	2006-02-22 00:00:00	Tested in Texas	11
+
 --- Test 5 LOAD DATA --
 /*!40019 SET @@session.max_insert_delayed_threads=0*/;
 /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
@@ -273,4 +342,11 @@ HEX(f)
 835C
 
 --- Test cleanup --
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (a INT NOT NULL KEY, b INT);
+INSERT INTO t1 VALUES(1,1);
+SELECT * FROM t1;
+a	b
+1	1
+FLUSH LOGS;
 DROP TABLE IF EXISTS t1, t2, t3, t04, t05, t4, t5;

mysql-test/t/rpl_row_mysqlbinlog.test

@@ -181,67 +181,67 @@ select "--- Test 3 First Remote test --" as "";
 --exec $MYSQL_BINLOG --short-form --local-load=$MYSQLTEST_VARDIR/tmp/ --read-from-remote-server --user=root --host=127.0.0.1 --port=$MASTER_MYPORT master-bin.000001
 
 # This part is disabled due to bug #17654
-################### Start Bug 17654 ######################
-#--disable_query_log
-#select "--- Test 4 Second Remote test --" as "";
-#--enable_query_log
-#--exec $MYSQL_BINLOG --read-from-remote-server --user=root --host=127.0.0.1 --port=$MASTER_MYPORT master-bin.000001 > $MYSQLTEST_VARDIR/tmp/remote.sql
 
-#--exec $MYSQL_BINLOG --read-from-remote-server --user=root --host=127.0.0.1 --port=$MASTER_MYPORT master-bin.000002 >> $MYSQLTEST_VARDIR/tmp/remote.sql
+--disable_query_log
+select "--- Test 4 Second Remote test --" as "";
+--enable_query_log
+--exec $MYSQL_BINLOG --read-from-remote-server --user=root --host=127.0.0.1 --port=$MASTER_MYPORT master-bin.000001 > $MYSQLTEST_VARDIR/tmp/remote.sql
+
+--exec $MYSQL_BINLOG --read-from-remote-server --user=root --host=127.0.0.1 --port=$MASTER_MYPORT master-bin.000002 >> $MYSQLTEST_VARDIR/tmp/remote.sql
 
 # Now that we have our file, lets get rid of the current database.
 # Cleanup the master and the slave and try to recreate.
 
-#DROP TABLE t1;
-#DROP TABLE t2;
-#DROP TABLE t3;
+DROP TABLE t1;
+DROP TABLE t2;
+DROP TABLE t3;
 
-#sync_slave_with_master;
+sync_slave_with_master;
 
 #we expect STOP SLAVE to produce a warning as the slave is stopped
 #(the server was started with skip-slave-start)
 
-#--disable_warnings
-#stop slave;
-#--enable_warnings
-#--require r/slave-stopped.result
-#show status like 'Slave_running';
-#connection master;
-#reset master;
-#connection slave;
-#reset slave;
-#start slave;
-#--require r/slave-running.result
-#show status like 'Slave_running';
-#connection master;
+--disable_warnings
+stop slave;
+--enable_warnings
+--require r/slave-stopped.result
+show status like 'Slave_running';
+connection master;
+reset master;
+connection slave;
+reset slave;
+start slave;
+--require r/slave-running.result
+show status like 'Slave_running';
+connection master;
 
 # We should be clean at this point, now we will run in the file from above.
 
-#--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/remote.sql"
+--exec $MYSQL -e "source $MYSQLTEST_VARDIR/tmp/remote.sql"
 
 # Lets Check the tables on the Master
 
-#SELECT COUNT(*) from t1;
-#SELECT COUNT(*) from t2;
-#SELECT COUNT(*) from t3;
-#SELECT * FROM t1 ORDER BY word LIMIT 5;
-#SELECT * FROM t2 ORDER BY id LIMIT 5;
-#SELECT c1, c3, c4, c5  FROM t3 ORDER BY c1 LIMIT 5;
+SELECT COUNT(*) from t1;
+SELECT COUNT(*) from t2;
+SELECT COUNT(*) from t3;
+SELECT * FROM t1 ORDER BY word LIMIT 5;
+SELECT * FROM t2 ORDER BY id LIMIT 5;
+SELECT c1, c3, c4, c5  FROM t3 ORDER BY c1 LIMIT 5;
 
 # Should have the same on the slave;
 
-#sync_slave_with_master;
-#SELECT COUNT(*) from t1;
-#SELECT COUNT(*) from t2;
-#SELECT COUNT(*) from t3;
-#SELECT * FROM t1 ORDER BY word LIMIT 5;
-#SELECT * FROM t2 ORDER BY id LIMIT 5;
-#SELECT c1, c3, c4, c5  FROM t3 ORDER BY c1 LIMIT 5;
-#connection master;
+sync_slave_with_master;
+SELECT COUNT(*) from t1;
+SELECT COUNT(*) from t2;
+SELECT COUNT(*) from t3;
+SELECT * FROM t1 ORDER BY word LIMIT 5;
+SELECT * FROM t2 ORDER BY id LIMIT 5;
+SELECT c1, c3, c4, c5  FROM t3 ORDER BY c1 LIMIT 5;
+connection master;
 
 # We should be gold by the time, so I will get rid of our file.
 
-#--exec rm $MYSQLTEST_VARDIR/tmp/remote.sql
+--exec rm $MYSQLTEST_VARDIR/tmp/remote.sql
 ################### End Bug 17654 ######################
 
 # LOAD DATA
@@ -313,7 +313,34 @@ select "--- Test cleanup --" as "";
 --enable_query_log
 # clean up
 connection master;
-DROP TABLE IF EXISTS t1, t2, t3, t04, t05, t4, t5; 
 sync_slave_with_master;
 
+connection master;
+
+# BUG#17654 also test mysqlbinlog to ensure it can read the binlog from a remote server 
+# and ensure that the results are the same as if read from a file (the same file).
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1 (a INT NOT NULL KEY, b INT);
+
+INSERT INTO t1 VALUES(1,1);
+
+SELECT * FROM t1;
+
+FLUSH LOGS;
+
+--exec $MYSQL_BINLOG --read-from-remote-server --user=root --host=127.0.0.1 --port=$MASTER_MYPORT master-bin.000001 > $MYSQLTEST_VARDIR/tmp/remote.sql
+--exec $MYSQL_BINLOG $MYSQLTEST_VARDIR/log/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/local.sql
+
+--diff_files $MYSQLTEST_VARDIR/tmp/local.sql $MYSQLTEST_VARDIR/tmp/remote.sql
+
+--exec rm $MYSQLTEST_VARDIR/tmp/remote.sql
+
+--exec rm $MYSQLTEST_VARDIR/tmp/local.sql
+
+DROP TABLE IF EXISTS t1, t2, t3, t04, t05, t4, t5; 
+
 # End of 4.1 tests