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:
  BUG#17654 : --read-from-remote-server causes core
  
  This patch corrects a problem when reading from a remote host. The temp_buf 
  variable of the log_event class is undefined. This patch assigns the temp_buf
  variable to the address of the incoming stream. This allows the print functions
  to print the binlog events correctly.
mysql-test/r/rpl_row_mysqlbinlog.result:
  BUG#17654 : --read-from-remote-server causes core
  
  This patch adds the results for the test that were disabled when the bug report
  was investigated. The patch also adds an additional test was added to ensure 
  the output of reading from a remote host is the same as reading from a local file.
mysql-test/t/rpl_row_mysqlbinlog.test:
  BUG#17654 : --read-from-remote-server causes core
  
  This patch enables the portions of the test that were disabled when the bug report
  was investigated. The patch also adds an additional test was added to ensure 
  the output of reading from a remote host is the same as reading from a local file.

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