Correctly handle reuse of screens in yaml file.

tests/bitmaps/TestBmpBlock.py

 #!/usr/bin/python -tt
 #
 # Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unit tests for bmpblk_utility.
 """
 
 import os
@@ skipping 116 matching lines @@
     self.assertEqual(0, rc)
     rc, out, err = runprog(prog, '-c', 'case_order2.yaml', 'ORDER2')
     self.assertEqual(0, rc)
     rc, out, err = runprog('/usr/bin/cmp', 'ORDER1', 'ORDER2')
     self.assertEqual(0, rc)
 
   def tearDown(self):
     rc, out, err = runprog('/bin/rm', '-f', 'ORDER1', 'ORDER2')
     self.assertEqual(0, rc)
 
+class TestReuse(unittest.TestCase):
+
+  def setUp(self):
+    rc, out, err = runprog('/bin/rm', '-rf', './FOO_DIR', 'FOO')
+    self.assertEqual(0, rc)
+
+  def testReuse(self):
+    """Reusing screens in the yaml file should be okay"""
+    rc, out, err = runprog(prog, '-c', 'case_reuse.yaml', 'FOO')
+    self.assertEqual(0, rc)
+    rc, out, err = runprog(prog, '-x', '-d', './FOO_DIR', 'FOO')
+    self.assertEqual(0, rc)
+    os.chdir('./FOO_DIR')
+    rc, out, err = runprog(prog, '-c', 'config.yaml', 'BAR')
+    self.assertEqual(0, rc)
+    rc, out, err = runprog('/usr/bin/cmp', '../FOO', 'BAR')
+    self.assertEqual(0, rc)
+    os.chdir('..')
+
+  def tearDown(self):
+    rc, out, err = runprog('/bin/rm', '-rf', './FOO_DIR', 'FOO')
+    self.assertEqual(0, rc)
+
 
 # Run these tests
 if __name__ == '__main__':
   varname = 'BMPBLK'
   if varname not in os.environ:
     print('You must specify the path to bmpblk_utility in the $%s '
           'environment variable.' % varname)
     sys.exit(1)
   prog = os.environ[varname]
   print "Testing prog...", prog
   unittest.main()