sql/log.cc

    don't set LOG_EVENT_BINLOG_IN_USE_F for relay logs
sql/sql_repl.cc
    clear LOG_EVENT_BINLOG_IN_USE_F flag before sending an event to a slave

sql/log.cc

@@ -613,6 +613,11 @@ bool MYSQL_LOG::open(const char *log_name,
         even if this is not the very first binlog.
       */
       Format_description_log_event s(BINLOG_VERSION);
+      /*
+        don't set LOG_EVENT_BINLOG_IN_USE_F for SEQ_READ_APPEND io_cache
+        as we won't be able to reset it later
+      */
+      if (io_cache_type == WRITE_CACHE)
         s.flags|= LOG_EVENT_BINLOG_IN_USE_F;
       if (!s.is_valid())
         goto err;

sql/sql_repl.cc

@@ -456,6 +456,7 @@ impossible position";
        {
          binlog_can_be_corrupted= test((*packet)[FLAGS_OFFSET+1] &
                                        LOG_EVENT_BINLOG_IN_USE_F);
+         (*packet)[FLAGS_OFFSET+1] &= ~LOG_EVENT_BINLOG_IN_USE_F;
          /*
            mark that this event with "log_pos=0", so the slave
            should not increment master's binlog position
@@ -512,8 +513,11 @@ impossible position";
 #endif
 
       if ((*packet)[EVENT_TYPE_OFFSET+1] == FORMAT_DESCRIPTION_EVENT)
+      {
         binlog_can_be_corrupted= test((*packet)[FLAGS_OFFSET+1] &
                                       LOG_EVENT_BINLOG_IN_USE_F);
+        (*packet)[FLAGS_OFFSET+1] &= ~LOG_EVENT_BINLOG_IN_USE_F;
+      }
       else if ((*packet)[EVENT_TYPE_OFFSET+1] == STOP_EVENT)
         binlog_can_be_corrupted= FALSE;