Reland of 'New run shell implementation for DeviceUtils'

build/android/pylib/device/adb_wrapper.py

 # Copyright 2013 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.
 
 """This module wraps Android's adb tool.
 
 This is a thin wrapper around the adb interface. Any additional complexity
 should be delegated to a higher level (ex. DeviceUtils).
 """
 
@@ skipping 153 matching lines @@
     Returns:
       The output of the shell command as a string.
 
     Raises:
       device_errors.AdbCommandFailedError: If the return code doesn't match
         |expect_rc|.
     """
     if expect_rc is None:
       actual_command = command
     else:
-      actual_command = '%s; echo $?;' % command
+      actual_command = '%s; echo %%$?;' % command.rstrip()
     output = self._DeviceAdbCmd(
         ['shell', actual_command], timeout, retries, check_error=False)
     if expect_rc is not None:
-      output_end = output.rstrip().rfind('\n') + 1
-      rc = output[output_end:].strip()
+      output_end = output.rfind('%')
+      if output_end < 0:
+        # causes the string for rc to become empty and also raise a ValueError
+        output_end = len(output)
+
+      try:
+        rc = int(output[output_end+1:])
+      except ValueError:
+        raise device_errors.AdbCommandFailedError(
+            ['shell'], 'command %r on device produced output %r where no'
+            ' valid return code was found' % (actual_command, output),
+            self._device_serial)
+
       output = output[:output_end]
-      if int(rc) != expect_rc:
-        raise device_errors.AdbCommandFailedError(
-            ['shell', command],
-            'shell command exited with code: %s' % rc,
-            self._device_serial)
+      if rc != expect_rc:
+        raise device_errors.AdbShellCommandFailedError(
+            command, rc, output, self._device_serial)
     return output
 
   def Logcat(self, filter_spec=None, timeout=_DEFAULT_TIMEOUT,
              retries=_DEFAULT_RETRIES):
     """Get the logcat output.
 
     Args:
       filter_spec: (optional) Spec to filter the logcat.
       timeout: (optional) Timeout per try in seconds.
       retries: (optional) Number of retries to attempt.
@@ skipping 182 matching lines @@
     """Restarts the adbd daemon with root permissions, if possible.
 
     Args:
       timeout: (optional) Timeout per try in seconds.
       retries: (optional) Number of retries to attempt.
     """
     output = self._DeviceAdbCmd(['root'], timeout, retries)
     if 'cannot' in output:
       raise device_errors.AdbCommandFailedError(['root'], output)