BUG#42749: infinite loop writing to row based binlog - processlist shows

"freeing items"

The calculation of the table map log event in the event constructor
was one byte shorter than what would be actually written. This would
lead to a mismatch between the number of bytes written and the event
end_log_pos, causing bad event alignment in the binlog (corrupted
binlog) or in the transaction cache while fixing positions
(MYSQL_BIN_LOG::write_cache). This could lead to impossible to read
binlog or even infinite loops in MYSQL_BIN_LOG::write_cache.

This patch addresses this issue by correcting the expected event
length in the Table_map_log_event constructor, when the field metadata
size exceeds 255.

sql/log_event.cc:
  Added the extra byte as net_store_length imposes.

3 files changed, 358 insertions, 2 deletions

diff --git a/mysql-test/suite/binlog/r/binlog_tbl_metadata.result b/mysql-test/suite/binlog/r/binlog_tbl_metadata.result
new file mode 100644
index 00000000000..a2f185edc85
--- /dev/null
+++ b/mysql-test/suite/binlog/r/binlog_tbl_metadata.result
@@ -0,0 +1,156 @@
+RESET MASTER;
+DROP TABLE IF EXISTS `t1`;
+CREATE TABLE `t1` (
+`c1` int(11) NOT NULL AUTO_INCREMENT,
+`c2` varchar(30) NOT NULL,
+`c3` varchar(30) DEFAULT NULL,
+`c4` varchar(30) DEFAULT NULL,
+`c5` varchar(30) DEFAULT NULL,
+`c6` varchar(30) DEFAULT NULL,
+`c7` varchar(30) DEFAULT NULL,
+`c8` varchar(30) DEFAULT NULL,
+`c9` varchar(30) DEFAULT NULL,
+`c10` varchar(30) DEFAULT NULL,
+`c11` varchar(30) DEFAULT NULL,
+`c12` varchar(30) DEFAULT NULL,
+`c13` varchar(30) DEFAULT NULL,
+`c14` varchar(30) DEFAULT NULL,
+`c15` varchar(30) DEFAULT NULL,
+`c16` varchar(30) DEFAULT NULL,
+`c17` varchar(30) DEFAULT NULL,
+`c18` varchar(30) DEFAULT NULL,
+`c19` varchar(30) DEFAULT NULL,
+`c20` varchar(30) DEFAULT NULL,
+`c21` varchar(30) DEFAULT NULL,
+`c22` varchar(30) DEFAULT NULL,
+`c23` varchar(30) DEFAULT NULL,
+`c24` varchar(30) DEFAULT NULL,
+`c25` varchar(30) DEFAULT NULL,
+`c26` varchar(30) DEFAULT NULL,
+`c27` varchar(30) DEFAULT NULL,
+`c28` varchar(30) DEFAULT NULL,
+`c29` varchar(30) DEFAULT NULL,
+`c30` varchar(30) DEFAULT NULL,
+`c31` varchar(30) DEFAULT NULL,
+`c32` varchar(30) DEFAULT NULL,
+`c33` varchar(30) DEFAULT NULL,
+`c34` varchar(30) DEFAULT NULL,
+`c35` varchar(30) DEFAULT NULL,
+`c36` varchar(30) DEFAULT NULL,
+`c37` varchar(30) DEFAULT NULL,
+`c38` varchar(30) DEFAULT NULL,
+`c39` varchar(30) DEFAULT NULL,
+`c40` varchar(30) DEFAULT NULL,
+`c41` varchar(30) DEFAULT NULL,
+`c42` varchar(30) DEFAULT NULL,
+`c43` varchar(30) DEFAULT NULL,
+`c44` varchar(30) DEFAULT NULL,
+`c45` varchar(30) DEFAULT NULL,
+`c46` varchar(30) DEFAULT NULL,
+`c47` varchar(30) DEFAULT NULL,
+`c48` varchar(30) DEFAULT NULL,
+`c49` varchar(30) DEFAULT NULL,
+`c50` varchar(30) DEFAULT NULL,
+`c51` varchar(30) DEFAULT NULL,
+`c52` varchar(30) DEFAULT NULL,
+`c53` varchar(30) DEFAULT NULL,
+`c54` varchar(30) DEFAULT NULL,
+`c55` varchar(30) DEFAULT NULL,
+`c56` varchar(30) DEFAULT NULL,
+`c57` varchar(30) DEFAULT NULL,
+`c58` varchar(30) DEFAULT NULL,
+`c59` varchar(30) DEFAULT NULL,
+`c60` varchar(30) DEFAULT NULL,
+`c61` varchar(30) DEFAULT NULL,
+`c62` varchar(30) DEFAULT NULL,
+`c63` varchar(30) DEFAULT NULL,
+`c64` varchar(30) DEFAULT NULL,
+`c65` varchar(30) DEFAULT NULL,
+`c66` varchar(30) DEFAULT NULL,
+`c67` varchar(30) DEFAULT NULL,
+`c68` varchar(30) DEFAULT NULL,
+`c69` varchar(30) DEFAULT NULL,
+`c70` varchar(30) DEFAULT NULL,
+`c71` varchar(30) DEFAULT NULL,
+`c72` varchar(30) DEFAULT NULL,
+`c73` varchar(30) DEFAULT NULL,
+`c74` varchar(30) DEFAULT NULL,
+`c75` varchar(30) DEFAULT NULL,
+`c76` varchar(30) DEFAULT NULL,
+`c77` varchar(30) DEFAULT NULL,
+`c78` varchar(30) DEFAULT NULL,
+`c79` varchar(30) DEFAULT NULL,
+`c80` varchar(30) DEFAULT NULL,
+`c81` varchar(30) DEFAULT NULL,
+`c82` varchar(30) DEFAULT NULL,
+`c83` varchar(30) DEFAULT NULL,
+`c84` varchar(30) DEFAULT NULL,
+`c85` varchar(30) DEFAULT NULL,
+`c86` varchar(30) DEFAULT NULL,
+`c87` varchar(30) DEFAULT NULL,
+`c88` varchar(30) DEFAULT NULL,
+`c89` varchar(30) DEFAULT NULL,
+`c90` varchar(30) DEFAULT NULL,
+`c91` varchar(30) DEFAULT NULL,
+`c92` varchar(30) DEFAULT NULL,
+`c93` varchar(30) DEFAULT NULL,
+`c94` varchar(30) DEFAULT NULL,
+`c95` varchar(30) DEFAULT NULL,
+`c96` varchar(30) DEFAULT NULL,
+`c97` varchar(30) DEFAULT NULL,
+`c98` varchar(30) DEFAULT NULL,
+`c99` varchar(30) DEFAULT NULL,
+`c100` varchar(30) DEFAULT NULL,
+`c101` varchar(30) DEFAULT NULL,
+`c102` varchar(30) DEFAULT NULL,
+`c103` varchar(30) DEFAULT NULL,
+`c104` varchar(30) DEFAULT NULL,
+`c105` varchar(30) DEFAULT NULL,
+`c106` varchar(30) DEFAULT NULL,
+`c107` varchar(30) DEFAULT NULL,
+`c108` varchar(30) DEFAULT NULL,
+`c109` varchar(30) DEFAULT NULL,
+`c110` varchar(30) DEFAULT NULL,
+`c111` varchar(30) DEFAULT NULL,
+`c112` varchar(30) DEFAULT NULL,
+`c113` varchar(30) DEFAULT NULL,
+`c114` varchar(30) DEFAULT NULL,
+`c115` varchar(30) DEFAULT NULL,
+`c116` varchar(30) DEFAULT NULL,
+`c117` varchar(30) DEFAULT NULL,
+`c118` varchar(30) DEFAULT NULL,
+`c119` varchar(30) DEFAULT NULL,
+`c120` varchar(30) DEFAULT NULL,
+`c121` varchar(30) DEFAULT NULL,
+`c122` varchar(30) DEFAULT NULL,
+`c123` varchar(30) DEFAULT NULL,
+`c124` varchar(30) DEFAULT NULL,
+`c125` varchar(30) DEFAULT NULL,
+`c126` varchar(30) DEFAULT NULL,
+`c127` varchar(30) DEFAULT NULL,
+`c128` varchar(30) DEFAULT NULL,
+`c129` varchar(30) DEFAULT NULL,
+`c130` varchar(30) DEFAULT NULL,
+`c131` varchar(30) DEFAULT NULL,
+`c132` varchar(30) DEFAULT NULL,
+`c133` varchar(30) DEFAULT NULL,
+`c134` varchar(30) DEFAULT NULL,
+`c135` varchar(30) DEFAULT NULL,
+`c136` varchar(30) DEFAULT NULL,
+`c137` varchar(30) DEFAULT NULL,
+`c138` varchar(30) DEFAULT NULL,
+`c139` varchar(30) DEFAULT NULL,
+`c140` varchar(30) DEFAULT NULL,
+`c141` varchar(30) DEFAULT NULL,
+`c142` varchar(30) DEFAULT NULL,
+`c143` varchar(30) DEFAULT NULL,
+`c144` varchar(30) DEFAULT NULL,
+`c145` varchar(30) DEFAULT NULL,
+`c146` varchar(30) DEFAULT NULL,
+PRIMARY KEY (`c1`)
+) ENGINE=InnoDB;
+LOCK TABLES `t1` WRITE;
+INSERT INTO `t1` VALUES ('1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1');
+DROP TABLE `t1`;
+FLUSH LOGS;
+=== Using mysqlbinlog to detect failure. Before the patch mysqlbinlog would find a corrupted event, thence would fail.
diff --git a/mysql-test/suite/binlog/t/binlog_tbl_metadata.test b/mysql-test/suite/binlog/t/binlog_tbl_metadata.test
new file mode 100644
index 00000000000..5e847ab5fbd
--- /dev/null
+++ b/mysql-test/suite/binlog/t/binlog_tbl_metadata.test
@@ -0,0 +1,199 @@
+#
+# BUG#42749: infinite loop writing to row based binlog - processlist shows
+# "freeing items"
+#
+# WHY
+# ===
+#   
+#   This bug would make table map event to report data_written one byte less
+#   than what would actually be written in its body. This would cause one byte shorter
+#   event end_log_pos. The ultimate impact was that it would make fixing the
+#   position in MYSQL_BIN_LOG::write_cache bogus or end up in an infinite loop.
+#
+# HOW
+# ===
+#
+#   Checking that the patch fixes the problem is done as follows:
+#     i) a table with several fields is created;
+#    ii) an insert is performed;
+#   iii) the logs are flushed;
+#    iv) mysqlbinlog is used to check if it succeeds.
+# 
+#   In step iv), before the bug was fixed, the test case would fail with
+#   mysqlbinlog reporting that it was unable to succeed in reading the event.
+#
+
+-- source include/have_log_bin.inc
+-- source include/have_innodb.inc
+-- source include/have_binlog_format_row.inc
+-- connection default
+
+RESET MASTER;
+
+-- disable_warnings
+DROP TABLE IF EXISTS `t1`;
+-- enable_warnings
+
+CREATE TABLE `t1` (
+  `c1` int(11) NOT NULL AUTO_INCREMENT,
+  `c2` varchar(30) NOT NULL,
+  `c3` varchar(30) DEFAULT NULL,
+  `c4` varchar(30) DEFAULT NULL,
+  `c5` varchar(30) DEFAULT NULL,
+  `c6` varchar(30) DEFAULT NULL,
+  `c7` varchar(30) DEFAULT NULL,
+  `c8` varchar(30) DEFAULT NULL,
+  `c9` varchar(30) DEFAULT NULL,
+  `c10` varchar(30) DEFAULT NULL,
+  `c11` varchar(30) DEFAULT NULL,
+  `c12` varchar(30) DEFAULT NULL,
+  `c13` varchar(30) DEFAULT NULL,
+  `c14` varchar(30) DEFAULT NULL,
+  `c15` varchar(30) DEFAULT NULL,
+  `c16` varchar(30) DEFAULT NULL,
+  `c17` varchar(30) DEFAULT NULL,
+  `c18` varchar(30) DEFAULT NULL,
+  `c19` varchar(30) DEFAULT NULL,
+  `c20` varchar(30) DEFAULT NULL,
+  `c21` varchar(30) DEFAULT NULL,
+  `c22` varchar(30) DEFAULT NULL,
+  `c23` varchar(30) DEFAULT NULL,
+  `c24` varchar(30) DEFAULT NULL,
+  `c25` varchar(30) DEFAULT NULL,
+  `c26` varchar(30) DEFAULT NULL,
+  `c27` varchar(30) DEFAULT NULL,
+  `c28` varchar(30) DEFAULT NULL,
+  `c29` varchar(30) DEFAULT NULL,
+  `c30` varchar(30) DEFAULT NULL,
+  `c31` varchar(30) DEFAULT NULL,
+  `c32` varchar(30) DEFAULT NULL,
+  `c33` varchar(30) DEFAULT NULL,
+  `c34` varchar(30) DEFAULT NULL,
+  `c35` varchar(30) DEFAULT NULL,
+  `c36` varchar(30) DEFAULT NULL,
+  `c37` varchar(30) DEFAULT NULL,
+  `c38` varchar(30) DEFAULT NULL,
+  `c39` varchar(30) DEFAULT NULL,
+  `c40` varchar(30) DEFAULT NULL,
+  `c41` varchar(30) DEFAULT NULL,
+  `c42` varchar(30) DEFAULT NULL,
+  `c43` varchar(30) DEFAULT NULL,
+  `c44` varchar(30) DEFAULT NULL,
+  `c45` varchar(30) DEFAULT NULL,
+  `c46` varchar(30) DEFAULT NULL,
+  `c47` varchar(30) DEFAULT NULL,
+  `c48` varchar(30) DEFAULT NULL,
+  `c49` varchar(30) DEFAULT NULL,
+  `c50` varchar(30) DEFAULT NULL,
+  `c51` varchar(30) DEFAULT NULL,
+  `c52` varchar(30) DEFAULT NULL,
+  `c53` varchar(30) DEFAULT NULL,
+  `c54` varchar(30) DEFAULT NULL,
+  `c55` varchar(30) DEFAULT NULL,
+  `c56` varchar(30) DEFAULT NULL,
+  `c57` varchar(30) DEFAULT NULL,
+  `c58` varchar(30) DEFAULT NULL,
+  `c59` varchar(30) DEFAULT NULL,
+  `c60` varchar(30) DEFAULT NULL,
+  `c61` varchar(30) DEFAULT NULL,
+  `c62` varchar(30) DEFAULT NULL,
+  `c63` varchar(30) DEFAULT NULL,
+  `c64` varchar(30) DEFAULT NULL,
+  `c65` varchar(30) DEFAULT NULL,
+  `c66` varchar(30) DEFAULT NULL,
+  `c67` varchar(30) DEFAULT NULL,
+  `c68` varchar(30) DEFAULT NULL,
+  `c69` varchar(30) DEFAULT NULL,
+  `c70` varchar(30) DEFAULT NULL,
+  `c71` varchar(30) DEFAULT NULL,
+  `c72` varchar(30) DEFAULT NULL,
+  `c73` varchar(30) DEFAULT NULL,
+  `c74` varchar(30) DEFAULT NULL,
+  `c75` varchar(30) DEFAULT NULL,
+  `c76` varchar(30) DEFAULT NULL,
+  `c77` varchar(30) DEFAULT NULL,
+  `c78` varchar(30) DEFAULT NULL,
+  `c79` varchar(30) DEFAULT NULL,
+  `c80` varchar(30) DEFAULT NULL,
+  `c81` varchar(30) DEFAULT NULL,
+  `c82` varchar(30) DEFAULT NULL,
+  `c83` varchar(30) DEFAULT NULL,
+  `c84` varchar(30) DEFAULT NULL,
+  `c85` varchar(30) DEFAULT NULL,
+  `c86` varchar(30) DEFAULT NULL,
+  `c87` varchar(30) DEFAULT NULL,
+  `c88` varchar(30) DEFAULT NULL,
+  `c89` varchar(30) DEFAULT NULL,
+  `c90` varchar(30) DEFAULT NULL,
+  `c91` varchar(30) DEFAULT NULL,
+  `c92` varchar(30) DEFAULT NULL,
+  `c93` varchar(30) DEFAULT NULL,
+  `c94` varchar(30) DEFAULT NULL,
+  `c95` varchar(30) DEFAULT NULL,
+  `c96` varchar(30) DEFAULT NULL,
+  `c97` varchar(30) DEFAULT NULL,
+  `c98` varchar(30) DEFAULT NULL,
+  `c99` varchar(30) DEFAULT NULL,
+  `c100` varchar(30) DEFAULT NULL,
+  `c101` varchar(30) DEFAULT NULL,
+  `c102` varchar(30) DEFAULT NULL,
+  `c103` varchar(30) DEFAULT NULL,
+  `c104` varchar(30) DEFAULT NULL,
+  `c105` varchar(30) DEFAULT NULL,
+  `c106` varchar(30) DEFAULT NULL,
+  `c107` varchar(30) DEFAULT NULL,
+  `c108` varchar(30) DEFAULT NULL,
+  `c109` varchar(30) DEFAULT NULL,
+  `c110` varchar(30) DEFAULT NULL,
+  `c111` varchar(30) DEFAULT NULL,
+  `c112` varchar(30) DEFAULT NULL,
+  `c113` varchar(30) DEFAULT NULL,
+  `c114` varchar(30) DEFAULT NULL,
+  `c115` varchar(30) DEFAULT NULL,
+  `c116` varchar(30) DEFAULT NULL,
+  `c117` varchar(30) DEFAULT NULL,
+  `c118` varchar(30) DEFAULT NULL,
+  `c119` varchar(30) DEFAULT NULL,
+  `c120` varchar(30) DEFAULT NULL,
+  `c121` varchar(30) DEFAULT NULL,
+  `c122` varchar(30) DEFAULT NULL,
+  `c123` varchar(30) DEFAULT NULL,
+  `c124` varchar(30) DEFAULT NULL,
+  `c125` varchar(30) DEFAULT NULL,
+  `c126` varchar(30) DEFAULT NULL,
+  `c127` varchar(30) DEFAULT NULL,
+  `c128` varchar(30) DEFAULT NULL,
+  `c129` varchar(30) DEFAULT NULL,
+  `c130` varchar(30) DEFAULT NULL,
+  `c131` varchar(30) DEFAULT NULL,
+  `c132` varchar(30) DEFAULT NULL,
+  `c133` varchar(30) DEFAULT NULL,
+  `c134` varchar(30) DEFAULT NULL,
+  `c135` varchar(30) DEFAULT NULL,
+  `c136` varchar(30) DEFAULT NULL,
+  `c137` varchar(30) DEFAULT NULL,
+  `c138` varchar(30) DEFAULT NULL,
+  `c139` varchar(30) DEFAULT NULL,
+  `c140` varchar(30) DEFAULT NULL,
+  `c141` varchar(30) DEFAULT NULL,
+  `c142` varchar(30) DEFAULT NULL,
+  `c143` varchar(30) DEFAULT NULL,
+  `c144` varchar(30) DEFAULT NULL,
+  `c145` varchar(30) DEFAULT NULL,
+  `c146` varchar(30) DEFAULT NULL,
+  PRIMARY KEY (`c1`)
+) ENGINE=InnoDB;
+
+LOCK TABLES `t1` WRITE;
+
+INSERT INTO `t1` VALUES ('1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1','1');
+
+DROP TABLE `t1`;
+
+FLUSH LOGS;
+
+-- echo === Using mysqlbinlog to detect failure. Before the patch mysqlbinlog would find a corrupted event, thence would fail.
+
+-- let $MYSQLD_DATADIR= `SELECT @@datadir`;
+-- exec $MYSQL_BINLOG $MYSQLD_DATADIR/master-bin.000001 > $MYSQLTEST_VARDIR/tmp/mysqlbinlog_bug42749.binlog
+-- remove_file $MYSQLTEST_VARDIR/tmp/mysqlbinlog_bug42749.binlog
diff --git a/sql/log_event.cc b/sql/log_event.cc
index a10a36f3b43..a878e9a2f9d 100644
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@@ -7861,10 +7861,11 @@ Table_map_log_event::Table_map_log_event(THD *thd, TABLE *tbl, ulong tid,
 
   /*
     Now set the size of the data to the size of the field metadata array
-    plus one or two bytes for number of elements in the field metadata array.
+    plus one or three bytes (see pack.c:net_store_length) for number of 
+    elements in the field metadata array.
   */
   if (m_field_metadata_size > 255)
-    m_data_size+= m_field_metadata_size + 2; 
+    m_data_size+= m_field_metadata_size + 3; 
   else
     m_data_size+= m_field_metadata_size + 1;