Experimental lexer: tiny test fix.

tools/lexer_generator/run_lexing_tests.py

 # Copyright 2013 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 28 matching lines @@
   if len(sys.argv) < 4:
     error_message = ('Usage:' + sys.argv[0] +
                      'LEXER_SHELL_PATH FILE_LIST_FILE PARALLEL_PROCESS_COUNT ' +
                      '[OTHER_ARGS]')
     print >> sys.stderr, error_message
     sys.exit(1)
   lexer_shell = sys.argv[1]
   file_file = sys.argv[2]
   process_count = int(sys.argv[3])
   with open(file_file, 'r') as f:
-    test_files = f.read().split('\n')
+    test_files = [filename for filename in f.read().split('\n') if filename]
 
   with open('/dev/null', 'w') as dev_null:
     processes = []
     for i, f in enumerate(test_files):
       lexer_shell_args = [lexer_shell, f, '--break-after-illegal'] + sys.argv[4:]
       processes.append((f, subprocess.Popen(lexer_shell_args, stdout=dev_null)))
       if i % process_count == process_count - 1:
         wait_processes(processes)
         processes = []
 
     wait_processes(processes)