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

build/android/pylib/utils/md5sum.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.
 
 import collections
 import logging
 import os
+import re
 import tempfile
 import types
 
 from pylib import cmd_helper
 from pylib import constants
 from pylib.utils import device_temp_file
 
 HashAndPath = collections.namedtuple('HashAndPath', ['hash', 'path'])
 
 MD5SUM_DEVICE_LIB_PATH = '/data/local/tmp/md5sum/'
 MD5SUM_DEVICE_BIN_PATH = MD5SUM_DEVICE_LIB_PATH + 'md5sum_bin'
 
 MD5SUM_DEVICE_SCRIPT_FORMAT = (
     'test -f {path} -o -d {path} '
     '&& LD_LIBRARY_PATH={md5sum_lib} {device_pie_wrapper} {md5sum_bin} {path}')
 
+_STARTS_WITH_CHECKSUM_RE = re.compile(r'^\s*[0-9a-fA-f]{32}\s+')
+
 
 def CalculateHostMd5Sums(paths):
   """Calculates the MD5 sum value for all items in |paths|.
 
   Args:
     paths: A list of host paths to md5sum.
   Returns:
     A list of named tuples with 'hash' and 'path' attributes.
   """
   if isinstance(paths, basestring):
@@ skipping 31 matching lines @@
           MD5SUM_DEVICE_SCRIPT_FORMAT.format(
               path=p, md5sum_lib=MD5SUM_DEVICE_LIB_PATH,
               device_pie_wrapper=device_pie_wrapper,
               md5sum_bin=MD5SUM_DEVICE_BIN_PATH)
           for p in paths)
       md5sum_script_file.write('; '.join(md5sum_script))
       md5sum_script_file.flush()
       device.adb.Push(md5sum_script_file.name, md5sum_device_script_file.name)
       out = device.RunShellCommand(['sh', md5sum_device_script_file.name])
 
-  return [HashAndPath(*l.split(None, 1)) for l in out if l]
+  return [HashAndPath(*l.split(None, 1))
+          for l in out
+          if l and _STARTS_WITH_CHECKSUM_RE.match(l)]