Merge romeo.(none):/home/bkroot/mysql-5.1-new-rpl

into  romeo.(none):/home/bk/b21474-mysql-5.1-new-rpl

sql/log_event.cc

@@ -2517,19 +2517,19 @@ int Format_description_log_event::exec_event(struct st_relay_log_info* rli)
   if (server_id == (uint32) ::server_id)
   {
     /*
-      Do not modify rli->group_master_log_pos, as this event did not exist on
-      the master. That is, just update the *relay log* coordinates; this is
-      done by passing log_pos=0 to inc_group_relay_log_pos, like we do in
-      Stop_log_event::exec_event().
-      If in a transaction, don't touch group_* coordinates.
-    */
-    if (thd->options & OPTION_BEGIN)
-      rli->inc_event_relay_log_pos();
-    else
-    {
-      rli->inc_group_relay_log_pos(0);
-      flush_relay_log_info(rli);
-    }
+      We only increase the relay log position if we are skipping
+      events and do not touch any group_* variables, nor flush the
+      relay log info.  If there is a crash, we will have to re-skip
+      the events again, but that is a minor issue.
+
+      If we do not skip stepping the group log position (and the
+      server id was changed when restarting the server), it might well
+      be that we start executing at a position that is invalid, e.g.,
+      at a Rows_log_event or a Query_log_event preceeded by a
+      Intvar_log_event instead of starting at a Table_map_log_event or
+      the Intvar_log_event respectively.
+     */
+    rli->inc_event_relay_log_pos();
     DBUG_RETURN(0);
   }
 

sql/slave.cc

@@ -3101,17 +3101,22 @@ static int exec_relay_log_event(THD* thd, RELAY_LOG_INFO* rli)
          type_code != START_EVENT_V3 && type_code!= FORMAT_DESCRIPTION_EVENT))
     {
       DBUG_PRINT("info", ("event skipped"));
-      if (thd->options & OPTION_BEGIN)
-        rli->inc_event_relay_log_pos();
-      else
-      {
-        rli->inc_group_relay_log_pos((type_code == ROTATE_EVENT ||
-                                      type_code == STOP_EVENT ||
-                                      type_code == FORMAT_DESCRIPTION_EVENT) ?
-                                     LL(0) : ev->log_pos,
-                                     1/* skip lock*/);
-        flush_relay_log_info(rli);
-      }
+      /*
+        We only skip the event here and do not increase the group log
+        position.  In the event that we have to restart, this means
+        that we might have to skip the event again, but that is a
+        minor issue.
+
+        If we were to increase the group log position when skipping an
+        event, it might be that we are restarting at the wrong
+        position and have events before that we should have executed,
+        so not increasing the group log position is a sure bet in this
+        case.
+
+        In this way, we just step the group log position when we
+        *know* that we are at the end of a group.
+       */
+      rli->inc_event_relay_log_pos();
 
       /*
         Protect against common user error of setting the counter to 1