sql/mysqld.cc

    fixed auto set of server id
sql/sql_repl.cc
    do not allow slave to replicate if master id was not supplied
sql/sql_repl.h
    fix for server_id

sql/mysqld.cc

@@ -188,6 +188,8 @@ I_List<i_string> replicate_do_db, replicate_ignore_db;
 I_List<i_string> binlog_do_db, binlog_ignore_db;
 
 uint32 server_id = 0; // server id for replication
+bool server_id_supplied = 0; // if we guessed server_id , we need to know
+// about it
 uint mysql_port;
 uint test_flags, select_errors=0, dropping_tables=0,ha_open_options=0;
 uint volatile thread_count=0, thread_running=0, kill_cached_threads=0,
@@ -1497,8 +1499,22 @@ int main(int argc, char **argv)
     open_log(&mysql_update_log, glob_hostname, opt_update_logname, "",
 	     LOG_NEW);
 
-  if (!server_id)
-    server_id= !master_host ? 1 : 2;
+  if (opt_bin_log && !server_id)
+    {
+     server_id= !master_host ? 1 : 2;
+     switch(server_id)
+       {
+       case 1:
+	 sql_print_error("Warning: one should set \
+server_id to a non-0 value if log-bin is enabled. Will log updates to \
+ binary log, but will not accept connections from slaves");
+         break;
+       default:
+	 sql_print_error("Warning: one should set server_id to a non-0 value\
+if  master_host is set. The server  will not act as a slave");
+	 break;
+       }
+    }
   if (opt_bin_log)
   {
     if (!opt_bin_logname)
@@ -3181,6 +3197,7 @@ static void get_options(int argc,char **argv)
     }
     case OPT_SERVER_ID:
       server_id = atoi(optarg);
+      server_id_supplied = 1;
       break;
     case OPT_DELAY_KEY_WRITE:
       ha_open_options|=HA_OPEN_DELAY_KEY_WRITE;

sql/sql_repl.cc

@@ -243,7 +243,12 @@ void mysql_binlog_send(THD* thd, char* log_ident, ulong pos, ushort flags)
     errmsg = "Binary log is not open";
     goto err;
   }
-
+  if(!server_id_supplied)
+    {
+      errmsg = "Misconfigured master - server id was not set";
+      goto err;
+    }
+  
   if (log_ident[0])
     mysql_bin_log.make_log_name(search_file_name, log_ident);
   else
@@ -498,7 +503,7 @@ int start_slave(THD* thd , bool net_report)
     return 1;
   pthread_mutex_lock(&LOCK_slave);
   if(!slave_running)
-    if(glob_mi.inited && glob_mi.host)
+    if(glob_mi.inited && glob_mi.host && server_id_supplied)
       {
 	pthread_t hThread;
 	if(pthread_create(&hThread, &connection_attrib, handle_slave, 0))
@@ -507,7 +512,8 @@ int start_slave(THD* thd , bool net_report)
 	  }
       }
     else
-      err = "Master host not set or master info not initialized";
+      err = "Master host not set, master info not initialized, or server id \
+not configured";
   else
     err =  "Slave already running";
 

sql/sql_repl.h

@@ -5,6 +5,8 @@
 
 extern char* master_host;
 extern my_string opt_bin_logname, master_info_file;
+extern uint32 server_id;
+extern bool server_id_supplied;
 extern I_List<i_string> binlog_do_db, binlog_ignore_db;
 
 int start_slave(THD* thd = 0, bool net_report = 1);