Bug #4629 Crash after SLAVE STOP, if the IO thread is in special state.

client.c:
  Added call to clear_slave_vio inside end_server only when under Windows with repliaction
slave.cc:
  Added clear_slave_vio function for clearing active vio on THD under Windows replication

sql-common/client.c

@@ -133,6 +133,11 @@ static void mysql_close_free(MYSQL *mysql);
 static int wait_for_data(my_socket fd, uint timeout);
 #endif
 
+#if defined(__WIN__) && defined(HAVE_REPLICATION) && defined(MYSQL_SERVER)
+void clear_slave_vio( MYSQL* mysql );
+#endif
+
+
 /****************************************************************************
   A modified version of connect().  my_connect() allows you to specify
   a timeout value, in seconds, that we should wait until we
@@ -818,6 +823,12 @@ void end_server(MYSQL *mysql)
     init_sigpipe_variables
     DBUG_PRINT("info",("Net: %s", vio_description(mysql->net.vio)));
     set_sigpipe(mysql);
+
+#if defined(__WIN__) && defined(HAVE_REPLICATION) && defined(MYSQL_SERVER)
+	/* if this mysql is one of our connections to the master, then clear it */
+	clear_slave_vio( mysql );
+#endif
+
     vio_delete(mysql->net.vio);
     reset_sigpipe(mysql);
     mysql->net.vio= 0;          /* Marker */

sql/slave.cc

@@ -4383,4 +4383,26 @@ template class I_List_iterator<i_string>;
 template class I_List_iterator<i_string_pair>;
 #endif
 
+
+#ifdef __WIN__
+extern "C" void clear_slave_vio( MYSQL* mysql )
+{
+	if (active_mi->mysql == mysql)
+		active_mi->io_thd->clear_active_vio();
+	/* TODO: use code like below when multi-master is in place */
+	/*	LIST *cur = &master_list;
+	if (((MASTER_INFO*)cur->data)->mysql == mysql)
+	{
+		MASTER_INFO *mi = (MASTER_INFO*)cur->data;
+		mi->io_thd->clear_active_vio();
+		return;
+	}
+	else
+		cur = cur->next;*/
+}
+#endif
+
+
+
+
 #endif /* HAVE_REPLICATION */