Bug #62443 "DROP DATABASE test" fails with error 17

Description:
After a new install a "DROP DATABASE test;" returns error 17.

$ perror 17
OS error code  17:  File exists

The problem is that there is a .empty file in the test directory.

This is likely caused by this part of 
# We need to create empty directories (data/test) the installation.  
# This does not work with current CPack due to http://www.cmake.org/Bug/view.php?id=8767
# Avoid completely empty directories and install dummy file instead.
SET(DUMMY_FILE ${CMAKE_CURRENT_BINARY_DIR}/.empty )
FILE(WRITE ${DUMMY_FILE} "")
INSTALL(FILES ${DUMMY_FILE} DESTINATION data/test COMPONENT DataFiles)

How to repeat:
Install MySQL

Version:
5.5.11, 5.5.13, 5.5.15, 5.6.3, 5.6.4

Suggested fix:
Solution 1:
Remove .empty in mysql_rm_db (sql/sql_db.cc)

Solution 2:
Use db.opt as DUMMY_FILE instead of .empty
AND remove .empty on upgrade.

This could be combined with things like Bug #29439 (charset settings missing for test db)

The code is from sql/CMakeLists.txt

Thank you foe the bug report.

[miguel@ilde ~]$ dbs/5.5/bin/mysql -uroot 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.17-debug Source distribution

Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> drop database test;
ERROR 1010 (HY000): Error dropping database (can't rmdir './test/', errno: 17)
mysql>

This is already reported internally as:
Bug 12845091 - .EMPTY FILE IN /DATA/TEST PREVENTS USERS FROM DROPPING TEST DB ON 5.5 AND 5.6

Fixed in 5.5.26