-- already approved; it would be nice if it goes into 3.23.57 --

Fix for bug 254 : the first Start_log_event after server startup will
have created=now(), whereas the next ones (FLUSH LOGS, auto rotation)
will have created=0. Before this, it was always now().
This way, slaves >=4.0.14 will know when they must
drop stale temp tables or not. The next task is now modify 4.0.14 to
implement this.


sql/log.cc:
  Fix for bug 254 : the first Start_log_event after server startup will
  have created=now(), whereas the next ones (FLUSH LOGS, auto rotation)
  will have created=0. Before this, it was always now().
  This way, slaves >=4.0.14 will know when they must
  drop stale temp tables or not.
sql/log_event.h:
  An explanation.
sql/sql_class.h:
  Prototype change (see log.cc).

1 files changed, 9 insertions, 0 deletions

diff --git a/sql/log_event.h b/sql/log_event.h
index 68696442490..bb1c9260e21 100644
--- a/sql/log_event.h
+++ b/sql/log_event.h
@@ -327,6 +327,15 @@ extern char server_version[SERVER_VERSION_LENGTH];
 class Start_log_event: public Log_event
 {
 public:
+  /* 
+     If this event is at the start of the first binary log since server startup
+     'created' should be the timestamp when the event (and the binary log) was
+     created. 
+     In the other case (i.e. this event is at the start of a binary log created
+     by FLUSH LOGS or automatic rotation), 'created' should be 0.
+     This "trick" is used by MySQL >=4.0.14 slaves to know if they must drop the
+     stale temporary tables or not.
+  */
   time_t created;
   uint16 binlog_version;
   char server_version[50];