[Android] Fix checksum handling when md5sum generates unexpected output.

build/android/pylib/device/device_utils.py

 # Copyright 2014 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.
 
 """Provides a variety of device interactions based on adb.
 
 Eventually, this will be based on adb_wrapper.
 """
 # pylint: disable=unused-argument
 
@@ skipping 836 matching lines @@
   def _GetChangedFilesImpl(self, host_path, device_path):
     real_host_path = os.path.realpath(host_path)
     try:
       real_device_path = self.RunShellCommand(
           ['realpath', device_path], single_line=True, check_return=True)
     except device_errors.CommandFailedError:
       real_device_path = None
     if not real_device_path:
       return [(host_path, device_path)]
 
-    host_hash_tuples = md5sum.CalculateHostMd5Sums([real_host_path])
+    host_checksums = md5sum.CalculateHostMd5Sums([real_host_path])
     device_paths_to_md5 = (
         real_device_path if os.path.isfile(real_host_path)
         else ('%s/%s' % (real_device_path, os.path.relpath(p, real_host_path))
-              for _, p in host_hash_tuples))
-    device_hash_tuples = md5sum.CalculateDeviceMd5Sums(
+              for p, _ in host_checksums.iteritems()))

[perezju, 2015/04/24 08:06:32]

for p in host_checksums.iterkeys()

[jbudorick, 2015/04/24 13:56:36]

Done.

+    device_checksums = md5sum.CalculateDeviceMd5Sums(
         device_paths_to_md5, self)
 
     if os.path.isfile(host_path):
-      if (not device_hash_tuples
-          or device_hash_tuples[0].hash != host_hash_tuples[0].hash):
-        return [(host_path, device_path)]
-      else:
-        return []
+      host_checksum = host_checksums.get(real_host_path)

[perezju, 2015/04/24 08:06:32]

I guess here the host_checksum *must* exist? I'm wondering what happens if both
host_checksum and device_checksum end up being None?

[jbudorick, 2015/04/24 13:56:36]

If we can't determine a checksum for a file, it's probably ok if we don't try to
push that file.

+      device_checksum = device_checksums.get(real_device_path)
+      return ([(host_path, device_path)]
+              if host_checksum != device_checksum
+              else [])

[perezju, 2015/04/24 08:06:32]

nit: I think the expanded version was easier to read.

[jbudorick, 2015/04/24 13:56:36]

Done.

     else:
-      device_tuple_dict = dict((d.path, d.hash) for d in device_hash_tuples)
       to_push = []
-      for host_hash, host_abs_path in (
-          (h.hash, h.path) for h in host_hash_tuples):
+      for host_abs_path, host_checksum in host_checksums.iteritems():
         device_abs_path = '%s/%s' % (
             real_device_path, os.path.relpath(host_abs_path, real_host_path))
-        if (device_abs_path not in device_tuple_dict
-            or device_tuple_dict[device_abs_path] != host_hash):
+        if (device_abs_path not in device_checksums
+            or device_checksums[device_abs_path] != host_checksum):

[perezju, 2015/04/24 08:06:32]

maybe just:

  if device_checksums.get(device_abs_path) != host_checksum:

[jbudorick, 2015/04/24 13:56:36]

Done.

           to_push.append((host_abs_path, device_abs_path))
       return to_push
 
   def _InstallCommands(self):
     if self._commands_installed is None:
       try:
         if not install_commands.Installed(self):
           install_commands.InstallCommands(self)
         self._commands_installed = True
       except Exception as e:
@@ skipping 685 matching lines @@
     """Returns client cache."""
     if client_name not in self._client_caches:
       self._client_caches[client_name] = {}
     return self._client_caches[client_name]
 
   def _ClearCache(self):
     """Clears all caches."""
     for client in self._client_caches:
       self._client_caches[client].clear()
     self._cache.clear()