From b2500829a3685d5546658eb969ff53a36872cdaf Mon Sep 17 00:00:00 2001
From: "guilhem@mysql.com" <>
Date: Thu, 9 Oct 2003 17:40:38 +0200
Subject: [PATCH] Make the slave die if master is 5.0. Indeed, 5.0 masters send
 a Format_description_log_event (or maybe it will be named
 Description_log_event) which is not recognized by 4.0, so a 4.0 can't be a
 slave of 5.0. We detect it early to produce a helpful message instead of
 "corrupted relay log" later.

---
 sql/slave.cc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sql/slave.cc b/sql/slave.cc
index 10d451a88bc..12698c8eda4 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -1017,11 +1017,12 @@ static int check_master_version(MYSQL* mysql, MASTER_INFO* mi)
       BINLOG_FORMAT_323_GEQ_57 ;
     break;
   case '4':
-  case '5':
     mi->old_format = BINLOG_FORMAT_CURRENT;
     break;
   default:
-    errmsg = "Master reported unrecognized MySQL version";
+    /* 5.0 is not supported */
+    errmsg = "Master reported an unrecognized MySQL version. Note that 4.0 \
+slaves can't replicate a 5.0 or newer master.";
     break;
   }