Filter out test directory which has only control files.

src/scripts/autotest

 #!/usr/bin/python
 
 # Copyright (c) 2010 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.
 #
 # A python wrapper to call autotest ebuild.
 
 import commands, logging, optparse, os, subprocess, sys
 
@@ skipping 132 matching lines @@
   if os.path.exists(board_blacklist_file):
     blacklist = [line.strip()
                  for line in open(board_blacklist_file).readlines()]
   else:
     blacklist = []
 
   all_tests = 'compilebench,dbench,disktest,netperf2,ltp,unixbench'
   site_tests = '../third_party/autotest/files/client/site_tests'
   for site_test in os.listdir(site_tests):
     test_path = os.path.join(site_tests, site_test)
-    if (os.path.exists(test_path) and os.path.isdir(test_path)
-        and site_test not in blacklist):
+    test_py = os.path.join(test_path, '%s.py' % site_test)
+    if (os.path.exists(test_path) and os.path.isdir(test_path) and
+        os.path.exists(test_py) and os.path.isfile(test_py) and
+        site_test not in blacklist):
       all_tests += ',' + site_test
 
   if 'all' == options.build.lower():
     if options.noprompt is not True:
       print 'You want to pre-build all client tests and it may take a long',
       print 'time to finish.'
       print 'Are you sure you want to continue?(N/y)',
       answer = sys.stdin.readline()
       if 'y' != answer[0].lower():
         print 'Use --build to specify tests you like to pre-compile. '
@@ skipping 41 matching lines @@
   else:
     ssh_key_file = os.path.join(os.path.dirname(me),
                                 'mod_for_test_scripts/ssh_keys/testing_rsa')
     os.chmod(ssh_key_file, 0400)
     run_autoserv(options.board, args)
 
 
 if __name__ == '__main__':
   main()