Merge pilot.blaudden:/home/msvensson/mysql/mysql-5.0-maint

into  pilot.blaudden:/home/msvensson/mysql/mysql-5.1-new-maint

sql/net_serv.cc

@@ -1126,6 +1126,7 @@ void my_net_set_read_timeout(NET *net, uint timeout)
   DBUG_PRINT("enter", ("timeout: %d", timeout));
   net->read_timeout= timeout;
 #ifdef NO_ALARM
+  if (net->vio)
     vio_timeout(net->vio, 0, timeout);
 #endif
   DBUG_VOID_RETURN;
@@ -1138,6 +1139,7 @@ void my_net_set_write_timeout(NET *net, uint timeout)
   DBUG_PRINT("enter", ("timeout: %d", timeout));
   net->write_timeout= timeout;
 #ifdef NO_ALARM
+  if (net->vio)
     vio_timeout(net->vio, 1, timeout);
 #endif
   DBUG_VOID_RETURN;