adds a signal, fixes a crash, adds syslogging, and marshals disks to d-bus

udev-device.cc

 // Copyright (c) 2011 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 <base/string_number_conversions.h>
 #include <base/string_util.h>
 #include <fcntl.h>
 #include <libudev.h>
 #include <sys/statvfs.h>
 #include <fstream>
@@ skipping 91 matching lines @@
   }
   return is_media_available;
 }
 
 std::vector<std::string> UdevDevice::GetMountedPaths() const {
   const std::string dev_file = udev_device_get_devnode(dev_);
   std::ifstream fs("/proc/mounts");
   if (fs.is_open()) {
     return ParseMountedPaths(dev_file, fs);
   }
+  LOG(INFO) << "unable to parse /proc/mounts";
   return std::vector<std::string>();
 }
 
 std::vector<std::string> UdevDevice::ParseMountedPaths(
     const std::string& device_path, std::istream& stream) {
   std::vector<std::string> mounted_paths;
   std::string line;
   while (std::getline(stream, line)) {
     std::vector<std::string> tokens;
     SplitString(line, ' ', &tokens);
@@ skipping 16 matching lines @@
   disk.set_is_media_available(IsMediaAvailable());
   disk.set_drive_model(GetProperty("ID_MODEL"));
   disk.set_label(GetProperty("ID_FS_LABEL"));
   disk.set_native_path(udev_device_get_syspath(dev_));
 
   const char *dev_file = udev_device_get_devnode(dev_);
   disk.set_device_file(dev_file);
 
   std::vector<std::string> mounted_paths = GetMountedPaths();
   disk.set_is_mounted(!mounted_paths.empty());
-  disk.set_mount_path(mounted_paths[0]);  // TODO(benchan): multiple paths
+
+  if (!mounted_paths.empty()) {
+    // TODO(benchan): support multiple paths
+    disk.set_mount_path(mounted_paths[0]);
+  }
 
   uint64 total_size, remaining_size;
   GetSizeInfo(&total_size, &remaining_size);
   disk.set_device_capacity(total_size);
   disk.set_bytes_remaining(remaining_size);
 
   return disk;
 }
 
 }  // namespace cros_disks