AU: Handle firmware update failure when booted from FW slot B.

subprocess.cc

 // Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "update_engine/subprocess.h"
 #include <stdlib.h>
 #include <string.h>
 #include <string>
 #include <unistd.h>
 #include <vector>
@@ skipping 11 matching lines @@
   SubprocessRecord* record = reinterpret_cast<SubprocessRecord*>(data);
 
   // Make sure we read any remaining process output. Then close the pipe.
   GStdoutWatchCallback(record->gioout, G_IO_IN, &record->stdout);
   int fd = g_io_channel_unix_get_fd(record->gioout);
   g_source_remove(record->gioout_tag);
   g_io_channel_unref(record->gioout);
   close(fd);
 
   g_spawn_close_pid(pid);
+  gint use_status = status;
+  if (WIFEXITED(status))
+    use_status = WEXITSTATUS(status);
+
   if (status) {
-    LOG(INFO) << "Subprocess status: " << status;
+    LOG(INFO) << "Subprocess status: " << use_status;
   }
   if (!record->stdout.empty()) {
     LOG(INFO) << "Subprocess output:\n" << record->stdout;
   }
   if (record->callback) {
-    record->callback(status, record->stdout, record->callback_data);
+    record->callback(use_status, record->stdout, record->callback_data);
   }
   Get().subprocess_records_.erase(record->tag);
 }
 
 void Subprocess::GRedirectStderrToStdout(gpointer user_data) {
   dup2(1, 2);
 }
 
 gboolean Subprocess::GStdoutWatchCallback(GIOChannel* source,
                                           GIOCondition condition,
@@ skipping 177 matching lines @@
        it != subprocess_records_.end(); ++it) {
     if (it->second->callback)
       return true;
   }
   return false;
 }
 
 Subprocess* Subprocess::subprocess_singleton_ = NULL;
 
 }  // namespace chromeos_update_engine