BUG#40482: server/mysqlbinlog crashes when reading invalid Incident_log_event

Problem: When an Incident_log_event contains a bad incident number on disk,
the server crashes with an assertion.
Fix: Don't validate input with assertions. Use errors.

mysql-test/include/cleanup_fake_relay_log.inc:
  Added auxiliary file to restore things that setup_fake_relay_log.inc did.
mysql-test/include/setup_fake_relay_log.inc:
  Added auxiliary file to setup replication from an existing relay log.
mysql-test/std_data/bug40482-bin.000001:
  Binlog file for rpl.rpl_binlog_corruption
mysql-test/suite/rpl/t/rpl_binlog_corruption.test:
  New test file.
sql/log_event.cc:
  Check that the incident number is correct at the time the event is constructed.
  Do not assert it at the time it is printed.
sql/log_event.h:
  Incident_log_event::is_valid() should verify that the incident number is valid.
sql/rpl_constants.h:
  Incident numbers should be hard-coded, since they may appear in files.

1 files changed, 4 insertions, 1 deletions

diff --git a/sql/log_event.h b/sql/log_event.h
index 3c109b798d3..db14341b51d 100644
--- a/sql/log_event.h
+++ b/sql/log_event.h
@@ -3870,7 +3870,10 @@ public:
 
   virtual Log_event_type get_type_code() { return INCIDENT_EVENT; }
 
-  virtual bool is_valid() const { return 1; }
+  virtual bool is_valid() const
+  {
+    return m_incident > INCIDENT_NONE && m_incident < INCIDENT_COUNT;
+  }
   virtual int get_data_size() {
     return INCIDENT_HEADER_LEN + 1 + m_message.length;
   }