Fix for BUG#3015

"(binlog, position) stored by InnoDB for a replication slave can be wrong".
This code contains conditional #if to distinguish between versions;
it should be merged into 4.1 and 5.0.


sql/ha_innodb.cc:
  correcting the binlog position stored in InnoDB in a slave.
sql/log_event.cc:
  better code to store the binlog position in InnoDB for a slave.
sql/slave.h:
  Better code for storing the binlog position in InnoDB for a slave.

sql/ha_innodb.cc

@@ -938,19 +938,17 @@ innobase_commit_low(
 	        return;
 	}
 
-        /* TODO: Guilhem should check if master_log_name, pending
-        etc. are right if the master log gets rotated! Possible bug here.
-	Comment by Heikki March 4, 2003. */
-
         if (current_thd->slave_thread) {
                 /* Update the replication position info inside InnoDB */
 
                 trx->mysql_master_log_file_name
                                         = active_mi->rli.master_log_name;
-                trx->mysql_master_log_pos = ((ib_longlong)
-					 (active_mi->rli.master_log_pos +
-					  active_mi->rli.event_len +
-					  active_mi->rli.pending));
+                trx->mysql_master_log_pos = (ib_longlong)
+#if MYSQL_VERSION_ID < 40100
+                  (active_mi->rli.future_master_log_pos);
+#else
+                  (active_mi->rli.future_group_master_log_pos);
+#endif
         }
 
 	trx_commit_for_mysql(trx);

sql/log_event.cc

@@ -1792,10 +1792,15 @@ int Query_log_event::exec_event(struct st_relay_log_info* rli)
 
   /*
     InnoDB internally stores the master log position it has processed so far;
-    position to store is really pos + pending + event_len
-    since we must store the pos of the END of the current log event
+    position to store is of the END of the current log event.
   */
-  rli->event_len= get_event_len();
+#if MYSQL_VERSION_ID < 40100
+  rli->future_master_log_pos= log_pos + get_event_len();
+#elif MYSQL_VERSION_ID < 50000
+  rli->future_group_master_log_pos= log_pos + get_event_len();
+#else
+  rli->future_group_master_log_pos= log_pos;
+#endif
   thd->query_error= 0;			// clear error
   thd->clear_error();
 
@@ -1935,6 +1940,17 @@ int Load_log_event::exec_event(NET* net, struct st_relay_log_info* rli,
   thd->query_error = 0;
   thd->clear_error();
 
+  if (!use_rli_only_for_errors)
+  {
+#if MYSQL_VERSION_ID < 40100
+    rli->future_master_log_pos= log_pos + get_event_len();
+#elif MYSQL_VERSION_ID < 50000
+    rli->future_group_master_log_pos= log_pos + get_event_len();
+#else
+    rli->future_group_master_log_pos= log_pos;
+#endif
+  }
+
   /*
     We test replicate_*_db rules. Note that we have already prepared the file to
     load, even if we are going to ignore and delete it now. So it is possible
@@ -2392,6 +2408,14 @@ int Execute_load_log_event::exec_event(struct st_relay_log_info* rli)
     lev->exec_event is the place where the table is loaded (it calls
     mysql_load()).
   */
+
+#if MYSQL_VERSION_ID < 40100
+    rli->future_master_log_pos= log_pos + get_event_len();
+#elif MYSQL_VERSION_ID < 50000
+    rli->future_group_master_log_pos= log_pos + get_event_len();
+#else
+    rli->future_group_master_log_pos= log_pos;
+#endif
   if (lev->exec_event(0,rli,1)) 
   {
     /*

sql/slave.h

@@ -177,12 +177,16 @@ typedef struct st_relay_log_info
   bool ignore_log_space_limit;
 
   /*
-    InnoDB internally stores the master log position it has processed
-    so far; the position to store is really the sum of 
-    pos + pending + event_len here since we must store the pos of the
-    END of the current log event
+    When it commits, InnoDB internally stores the master log position it has
+    processed so far; the position to store is the one of the end of the
+    committing event (the COMMIT query event, or the event if in autocommit
+    mode).
   */
-  int event_len;
+#if MYSQL_VERSION_ID < 40100
+  ulonglong future_master_log_pos;
+#else
+  ulonglong future_group_master_log_pos;
+#endif
 
   /*
     Needed for problems when slave stops and we want to restart it