get_native_path_case() now preserves the trailing os.sep.path and work with non-existing path.

tools/isolate/isolate_smoke_test.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import cStringIO
 import hashlib
 import json
 import logging
 import os
@@ skipping 588 matching lines @@
       self._expect_results(['symlink_partial.py'], None, None)
 
 
 class Isolate_trace_read_merge(IsolateModeBase):
   # Tests both trace, read and merge.
   # Warning: merge updates .isolate files. But they are currently in their
   # canonical format so they shouldn't be changed.
   LEVEL = isolate.STATS_ONLY
 
   def _check_merge(self, filename):
-    filepath = os.path.join(ROOT_DIR, 'data', 'isolate', filename)
+    filepath = isolate.trace_inputs.get_native_path_case(
+        os.path.join(ROOT_DIR, 'data', 'isolate', filename))
     expected = 'Updating %s\n' % filepath
     with open(filepath, 'rb') as f:
       old_content = f.read()
     out = self._execute('merge', filename, [], True) or ''
     self.assertEquals(expected, out)
     with open(filepath, 'rb') as f:
       new_content = f.read()
     self.assertEquals(old_content, new_content)
 
   def test_fail(self):
@@ skipping 256 matching lines @@
     output = self._execute('read', [], True)
     expected = {
       isolate.isolate_common.KEY_TRACKED: [
         '../../isolate.py',
         'touch_root.py',
       ],
     }
     self.assertEquals(self._wrap_in_condition(expected), output)
 
     output = self._execute('merge', [], True)
-    expected = 'Updating %s\n' % os.path.join(
-        self.root, 'data', 'isolate', 'touch_root.isolate')
+    expected = 'Updating %s\n' % isolate.trace_inputs.get_native_path_case(
+        os.path.join(self.root, 'data', 'isolate', 'touch_root.isolate'))
     self.assertEquals(expected, output)
     # In theory the file is going to be updated but in practice its content
     # won't change.
 
     # Clean the directory from the logs, which are OS-specific.
     isolate.trace_inputs.get_api().clean_trace(
         os.path.join(self.tempdir, 'isolate_smoke_test.results.log'))
     files = [
       'isolate_smoke_test.results',
       'isolate_smoke_test.state',
       os.path.join('root', 'data', 'isolate', 'touch_root.isolate'),
       os.path.join('root', 'data', 'isolate', 'touch_root.py'),
       os.path.join('root', 'isolate.py'),
     ]
     self.assertEquals(files, list_files_tree(self.tempdir))
 
 
 if __name__ == '__main__':
   VERBOSE = '-v' in sys.argv
   logging.basicConfig(level=logging.DEBUG if VERBOSE else logging.ERROR)
   unittest.main()