Bug #44442: Incident events are silent in mysqlbinlog output

      
In the output from mysqlbinlog, incident log events were
represented as just a comment. Since the incident log event
represents an incident that could cause the contents of the
database to change without being logged to the binary log,
it means that if the SQL is applied to a server, it could
potentially lead to that the databases are out of sync.

In order to handle that, this patch adds the statement "RELOAD
DATABASE" to the SQL output for the incident log event. This will
require a DBA to edit the file and handle the case as apropriate
before applying the output to a server.

mysql-test/suite/binlog/t/binlog_incident-master.opt:
  Options file to cause server to generate an incident log
  event when executing a REPLACE.
mysql-test/suite/binlog/t/binlog_incident.test:
  Test to check that the incident log event is represented
  correctly in the output from mysqlbinlog.
sql/log_event.cc:
  The incident log event now ouput a "RELOAD DATABASE" instead
  of just a comment. RELOAD DATABASE is not an existing command
  and will generate a syntax error.

mysql-test/suite/binlog/r/binlog_incident.result

+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3);
+SELECT * FROM t1;
+a
+1
+2
+3
+REPLACE INTO t1 VALUES (4);
+DROP TABLE t1;
+FLUSH LOGS;
+Contain RELOAD DATABASE
+1

mysql-test/suite/binlog/t/binlog_incident-master.opt

+--loose-debug=+d,incident_database_resync_on_replace
\ No newline at end of file

mysql-test/suite/binlog/t/binlog_incident.test

+# The purpose of this test is to provide a reference for how the
+# incident log event is represented in the output from the mysqlbinlog
+# program.
+
+source include/have_log_bin.inc;
+source include/have_debug.inc;
+
+let $MYSQLD_DATADIR= `select @@datadir`;
+
+CREATE TABLE t1 (a INT);
+
+INSERT INTO t1 VALUES (1),(2),(3);
+SELECT * FROM t1;
+
+# This will generate an incident log event and store it in the binary
+# log before the replace statement.
+REPLACE INTO t1 VALUES (4);
+
+DROP TABLE t1;
+FLUSH LOGS;
+
+exec $MYSQL_BINLOG --start-position=106 $MYSQLD_DATADIR/master-bin.000001 >$MYSQLTEST_VARDIR/tmp/binlog_incident-bug44442.sql;
+--disable_query_log
+eval SELECT cont LIKE '%RELOAD DATABASE; # Shall generate syntax error%' AS `Contain RELOAD DATABASE` FROM (SELECT load_file('$MYSQLTEST_VARDIR/tmp/binlog_incident-bug44442.sql') AS cont) AS tbl;
+--enable_query_log
+
+remove_file $MYSQLTEST_VARDIR/tmp/binlog_incident-bug44442.sql;
\ No newline at end of file

sql/log_event.cc

@@ -9311,7 +9311,7 @@ Incident_log_event::print(FILE *file,
 
   Write_on_release_cache cache(&print_event_info->head_cache, file);
   print_header(&cache, print_event_info, FALSE);
-  my_b_printf(&cache, "\n# Incident: %s", description());
+  my_b_printf(&cache, "\n# Incident: %s\nRELOAD DATABASE; # Shall generate syntax error\n", description());
 }
 #endif