desktop-file: fix stat() race

_dbus_desktop_file_load() used to stat the desktop file before reading
it, to verify its size. This is both racy and unnecessary since
_dbus_file_get_contents() which it uses stats the file anyway -- does
that however in a race-free fashion with fstat() instead of stat().

This patch gets rid of the redundant stat(). Also, since the desktop
file change logic requires the mtime of the file it read we now export
that in _dbus_file_get_contents().

This patch probably breaks Win32 builds, but afaik those are broken
anyway.

1 files changed, 193 insertions, 192 deletions

diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c
index e60e6144..1b834beb 100644
--- a/dbus/dbus-sysdeps-unix.c
+++ b/dbus/dbus-sysdeps-unix.c
@@ -1,11 +1,11 @@
 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
 /* dbus-sysdeps-unix.c Wrappers around UNIX system/libc features (internal to D-Bus implementation)
- * 
+ *
  * Copyright (C) 2002, 2003, 2006  Red Hat, Inc.
  * Copyright (C) 2003 CodeFactory AB
  *
  * Licensed under the Academic Free License version 2.1
- * 
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -15,7 +15,7 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
@@ -161,7 +161,7 @@ _dbus_open_unix_socket (int              *fd,
  * @param error return location for an error
  * @returns #FALSE if error is set
  */
-dbus_bool_t 
+dbus_bool_t
 _dbus_close_socket (int               fd,
                     DBusError        *error)
 {
@@ -474,7 +474,7 @@ _dbus_pipe_write (DBusPipe         *pipe,
                   DBusError        *error)
 {
   int written;
-  
+
   written = _dbus_write (pipe->fd_or_handle, buffer, start, len);
   if (written < 0)
     {
@@ -510,7 +510,7 @@ _dbus_pipe_close  (DBusPipe         *pipe,
 /**
  * Like _dbus_write_two() but only works on sockets and is thus
  * available on Windows.
- * 
+ *
  * @param fd the file descriptor
  * @param buffer1 first buffer
  * @param start1 first byte to write in first buffer
@@ -588,7 +588,7 @@ _dbus_write_socket_two (int               fd,
  *
  * Unlike _dbus_read_socket(), _dbus_read() is not available
  * on Windows.
- * 
+ *
  * @param fd the file descriptor to read from
  * @param buffer the buffer to append data to
  * @param count the amount of data to read
@@ -604,7 +604,7 @@ _dbus_read (int               fd,
   char *data;
 
   _dbus_assert (count >= 0);
-  
+
   start = _dbus_string_get_length (buffer);
 
   if (!_dbus_string_lengthen (buffer, count))
@@ -616,7 +616,7 @@ _dbus_read (int               fd,
   data = _dbus_string_get_data_len (buffer, start, count);
 
  again:
-  
+
   bytes_read = read (fd, data, count);
 
   if (bytes_read < 0)
@@ -639,7 +639,7 @@ _dbus_read (int               fd,
       if (bytes_read > 0)
         _dbus_verbose_bytes_of_string (buffer, start, bytes_read);
 #endif
-      
+
       return bytes_read;
     }
 }
@@ -647,7 +647,7 @@ _dbus_read (int               fd,
 /**
  * Thin wrapper around the write() system call that writes a part of a
  * DBusString and handles EINTR for you.
- * 
+ *
  * @param fd the file descriptor to write
  * @param buffer the buffer to write data from
  * @param start the first byte in the buffer to write
@@ -662,9 +662,9 @@ _dbus_write (int               fd,
 {
   const char *data;
   int bytes_written;
-  
+
   data = _dbus_string_get_const_data_len (buffer, start, len);
-  
+
  again:
 
   bytes_written = write (fd, data, len);
@@ -676,7 +676,7 @@ _dbus_write (int               fd,
   if (bytes_written > 0)
     _dbus_verbose_bytes_of_string (buffer, start, bytes_written);
 #endif
-  
+
   return bytes_written;
 }
 
@@ -714,7 +714,7 @@ _dbus_write_two (int               fd,
   _dbus_assert (start2 >= 0);
   _dbus_assert (len1 >= 0);
   _dbus_assert (len2 >= 0);
-  
+
 #ifdef HAVE_WRITEV
   {
     struct iovec vectors[2];
@@ -732,40 +732,40 @@ _dbus_write_two (int               fd,
         start2 = 0;
         len2 = 0;
       }
-   
+
     vectors[0].iov_base = (char*) data1;
     vectors[0].iov_len = len1;
     vectors[1].iov_base = (char*) data2;
     vectors[1].iov_len = len2;
 
   again:
-   
+
     bytes_written = writev (fd,
                             vectors,
                             data2 ? 2 : 1);
 
     if (bytes_written < 0 && errno == EINTR)
       goto again;
-   
+
     return bytes_written;
   }
 #else /* HAVE_WRITEV */
   {
     int ret1;
-    
+
     ret1 = _dbus_write (fd, buffer1, start1, len1);
     if (ret1 == len1 && buffer2 != NULL)
       {
         ret2 = _dbus_write (fd, buffer2, start2, len2);
         if (ret2 < 0)
           ret2 = 0; /* we can't report an error as the first write was OK */
-       
+
         return ret1 + ret2;
       }
     else
       return ret1;
   }
-#endif /* !HAVE_WRITEV */   
+#endif /* !HAVE_WRITEV */
 }
 
 #define _DBUS_MAX_SUN_PATH_LENGTH 99
@@ -787,7 +787,7 @@ _dbus_write_two (int               fd,
  * Creates a socket and connects it to the UNIX domain socket at the
  * given path.  The connection fd is returned, and is set up as
  * nonblocking.
- * 
+ *
  * Uses abstract sockets instead of filesystem-linked sockets if
  * requested (it's possible only on Linux; see "man 7 unix" on Linux).
  * On non-Linux abstract socket usage always fails.
@@ -806,14 +806,14 @@ _dbus_connect_unix_socket (const char     *path,
 {
   int fd;
   size_t path_len;
-  struct sockaddr_un addr;  
+  struct sockaddr_un addr;
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
 
   _dbus_verbose ("connecting to unix socket %s abstract=%d\n",
                  path, abstract);
-  
-  
+
+
   if (!_dbus_open_unix_socket (&fd, error))
     {
       _DBUS_ASSERT_ERROR_IS_SET(error);
@@ -838,7 +838,7 @@ _dbus_connect_unix_socket (const char     *path,
           _dbus_close (fd, NULL);
           return -1;
 	}
-	
+
       strncpy (&addr.sun_path[1], path, path_len);
       /* _dbus_verbose_bytes (addr.sun_path, sizeof (addr.sun_path)); */
 #else /* HAVE_ABSTRACT_SOCKETS */
@@ -860,9 +860,9 @@ _dbus_connect_unix_socket (const char     *path,
 
       strncpy (addr.sun_path, path, path_len);
     }
-  
+
   if (connect (fd, (struct sockaddr*) &addr, _DBUS_STRUCT_OFFSET (struct sockaddr_un, sun_path) + path_len) < 0)
-    {      
+    {
       dbus_set_error (error,
                       _dbus_error_from_errno (errno),
                       "Failed to connect to socket %s: %s",
@@ -870,14 +870,14 @@ _dbus_connect_unix_socket (const char     *path,
 
       _dbus_close (fd, NULL);
       fd = -1;
-      
+
       return -1;
     }
 
   if (!_dbus_set_fd_nonblocking (fd, error))
     {
       _DBUS_ASSERT_ERROR_IS_SET (error);
-      
+
       _dbus_close (fd, NULL);
       fd = -1;
 
@@ -902,10 +902,10 @@ _dbus_set_local_creds (int fd, dbus_bool_t on)
   dbus_bool_t retval = TRUE;
 
 #if defined(HAVE_CMSGCRED)
-  /* NOOP just to make sure only one codepath is used 
+  /* NOOP just to make sure only one codepath is used
    *      and to prefer CMSGCRED
    */
-#elif defined(LOCAL_CREDS) 
+#elif defined(LOCAL_CREDS)
   int val = on ? 1 : 0;
   if (setsockopt (fd, 0, LOCAL_CREDS, &val, sizeof (val)) < 0)
     {
@@ -950,7 +950,7 @@ _dbus_listen_unix_socket (const char     *path,
 
   _dbus_verbose ("listening on unix socket %s abstract=%d\n",
                  path, abstract);
-  
+
   if (!_dbus_open_unix_socket (&listen_fd, error))
     {
       _DBUS_ASSERT_ERROR_IS_SET(error);
@@ -961,7 +961,7 @@ _dbus_listen_unix_socket (const char     *path,
   _DBUS_ZERO (addr);
   addr.sun_family = AF_UNIX;
   path_len = strlen (path);
-  
+
   if (abstract)
     {
 #ifdef HAVE_ABSTRACT_SOCKETS
@@ -978,7 +978,7 @@ _dbus_listen_unix_socket (const char     *path,
           _dbus_close (listen_fd, NULL);
           return -1;
 	}
-      
+
       strncpy (&addr.sun_path[1], path, path_len);
       /* _dbus_verbose_bytes (addr.sun_path, sizeof (addr.sun_path)); */
 #else /* HAVE_ABSTRACT_SOCKETS */
@@ -1015,10 +1015,10 @@ _dbus_listen_unix_socket (const char     *path,
           _dbus_close (listen_fd, NULL);
           return -1;
 	}
-	
+
       strncpy (addr.sun_path, path, path_len);
     }
-  
+
   if (bind (listen_fd, (struct sockaddr*) &addr, _DBUS_STRUCT_OFFSET (struct sockaddr_un, sun_path) + path_len) < 0)
     {
       dbus_set_error (error, _dbus_error_from_errno (errno),
@@ -1052,19 +1052,19 @@ _dbus_listen_unix_socket (const char     *path,
       _dbus_close (listen_fd, NULL);
       return -1;
     }
-  
+
   /* Try opening up the permissions, but if we can't, just go ahead
    * and continue, maybe it will be good enough.
    */
   if (!abstract && chmod (path, 0777) < 0)
     _dbus_warn ("Could not set mode 0777 on socket %s\n",
                 path);
-  
+
   return listen_fd;
 }
 
 /**
- * Creates a socket and connects to a socket at the given host 
+ * Creates a socket and connects to a socket at the given host
  * and port. The connection fd is returned, and is set up as
  * nonblocking.
  *
@@ -1372,7 +1372,7 @@ write_credentials_byte (int             server_fd,
 {
   int bytes_written;
   char buf[1] = { '\0' };
-#if defined(HAVE_CMSGCRED) 
+#if defined(HAVE_CMSGCRED)
   union {
 	  struct cmsghdr hdr;
 	  char cred[CMSG_SPACE (sizeof (struct cmsgcred))];
@@ -1395,10 +1395,10 @@ write_credentials_byte (int             server_fd,
 #endif
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
  again:
 
-#if defined(HAVE_CMSGCRED) 
+#if defined(HAVE_CMSGCRED)
   bytes_written = sendmsg (server_fd, &msg, 0);
 #else
   bytes_written = write (server_fd, buf, 1);
@@ -1438,7 +1438,7 @@ write_credentials_byte (int             server_fd,
  * we got valid credentials. On some systems, such as Linux,
  * reading/writing the byte isn't actually required, but we do it
  * anyway just to avoid multiple codepaths.
- * 
+ *
  * Fails if no byte is available, so you must select() first.
  *
  * The point of the byte is that on some systems we have to
@@ -1460,8 +1460,8 @@ _dbus_read_credentials_socket  (int              client_fd,
   dbus_uid_t uid_read;
   dbus_pid_t pid_read;
   int bytes_read;
-  
-#ifdef HAVE_CMSGCRED 
+
+#ifdef HAVE_CMSGCRED
   union {
     struct cmsghdr hdr;
     char cred[CMSG_SPACE (sizeof (struct cmsgcred))];
@@ -1478,7 +1478,7 @@ _dbus_read_credentials_socket  (int              client_fd,
   pid_read = DBUS_PID_UNSET;
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   /* The POSIX spec certainly doesn't promise this, but
    * we need these assertions to fail as soon as we're wrong about
    * it so we can do the porting fixups
@@ -1520,7 +1520,7 @@ _dbus_read_credentials_socket  (int              client_fd,
        * normally only call read_credentials if the socket was ready
        * for reading
        */
-      
+
       dbus_set_error (error, _dbus_error_from_errno (errno),
                       "Failed to read credentials byte: %s",
                       _dbus_strerror (errno));
@@ -1556,9 +1556,9 @@ _dbus_read_credentials_socket  (int              client_fd,
 
   {
 #ifdef SO_PEERCRED
-    struct ucred cr;   
+    struct ucred cr;
     int cr_len = sizeof (cr);
-    
+
     if (getsockopt (client_fd, SOL_SOCKET, SO_PEERCRED, &cr, &cr_len) == 0 &&
 	cr_len == sizeof (cr))
       {
@@ -1608,9 +1608,9 @@ _dbus_read_credentials_socket  (int              client_fd,
           {
             _dbus_verbose ("Failed to adt_start_session(): %s\n", _dbus_strerror (errno));
           }
-        else 
+        else
           {
-            if (adt_set_from_ucred (adth, ucred, ADT_NEW)) 
+            if (adt_set_from_ucred (adth, ucred, ADT_NEW))
               {
                 _dbus_verbose ("Failed to adt_set_from_ucred(): %s\n", _dbus_strerror (errno));
               }
@@ -1666,7 +1666,7 @@ _dbus_read_credentials_socket  (int              client_fd,
           return FALSE;
         }
     }
-  
+
   return TRUE;
 }
 
@@ -1692,7 +1692,7 @@ _dbus_send_credentials_socket  (int              server_fd,
                                 DBusError       *error)
 {
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   if (write_credentials_byte (server_fd, error))
     return TRUE;
   else
@@ -1752,8 +1752,8 @@ _dbus_accept  (int listen_fd)
 }
 
 /**
- * Checks to make sure the given directory is 
- * private to the user 
+ * Checks to make sure the given directory is
+ * private to the user
  *
  * @param dir the name of the directory
  * @param error error return
@@ -1764,19 +1764,19 @@ _dbus_check_dir_is_private_to_user (DBusString *dir, DBusError *error)
 {
   const char *directory;
   struct stat sb;
-	
+
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-    
+
   directory = _dbus_string_get_const_data (dir);
-	
+
   if (stat (directory, &sb) < 0)
     {
       dbus_set_error (error, _dbus_error_from_errno (errno),
                       "%s", _dbus_strerror (errno));
-   
+
       return FALSE;
     }
-    
+
   if ((S_IROTH & sb.st_mode) || (S_IWOTH & sb.st_mode) ||
       (S_IRGRP & sb.st_mode) || (S_IWGRP & sb.st_mode))
     {
@@ -1784,7 +1784,7 @@ _dbus_check_dir_is_private_to_user (DBusString *dir, DBusError *error)
                      "%s directory is not private to the user", directory);
       return FALSE;
     }
-    
+
   return TRUE;
 }
 
@@ -1795,12 +1795,12 @@ fill_user_info_from_passwd (struct passwd *p,
 {
   _dbus_assert (p->pw_name != NULL);
   _dbus_assert (p->pw_dir != NULL);
-  
+
   info->uid = p->pw_uid;
   info->primary_gid = p->pw_gid;
   info->username = _dbus_strdup (p->pw_name);
   info->homedir = _dbus_strdup (p->pw_dir);
-  
+
   if (info->username == NULL ||
       info->homedir == NULL)
     {
@@ -1818,7 +1818,7 @@ fill_user_info (DBusUserInfo       *info,
                 DBusError          *error)
 {
   const char *username_c;
-  
+
   /* exactly one of username/uid provided */
   _dbus_assert (username != NULL || uid != DBUS_UID_UNSET);
   _dbus_assert (username == NULL || uid == DBUS_UID_UNSET);
@@ -1829,7 +1829,7 @@ fill_user_info (DBusUserInfo       *info,
   info->n_group_ids = 0;
   info->username = NULL;
   info->homedir = NULL;
-  
+
   if (username != NULL)
     username_c = _dbus_string_get_const_data (username);
   else
@@ -1839,7 +1839,7 @@ fill_user_info (DBusUserInfo       *info,
    * are always symmetrical, if not we have to add more configure
    * checks
    */
-  
+
 #if defined (HAVE_POSIX_GETPWNAM_R) || defined (HAVE_NONPOSIX_GETPWNAM_R)
   {
     struct passwd *p;
@@ -1943,7 +1943,7 @@ fill_user_info (DBusUserInfo       *info,
 
   /* Fill this in so we can use it to get groups */
   username_c = info->username;
-  
+
 #ifdef HAVE_GETGROUPLIST
   {
     gid_t *buf;
@@ -1959,7 +1959,7 @@ fill_user_info (DBusUserInfo       *info,
         dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
         goto failed;
       }
-    
+
     if (getgrouplist (username_c,
                       info->primary_gid,
                       buf, &buf_count) < 0)
@@ -1976,10 +1976,10 @@ fill_user_info (DBusUserInfo       *info,
            for the "id" command, and it turns out that they use an
            undocumented library function getgrouplist_2 (!) which is not
            declared in any header in /usr/include (!!). That did not seem
-           like the way to go here.  
+           like the way to go here.
         */
-        if (buf_count == initial_buf_count) 
-          { 
+        if (buf_count == initial_buf_count)
+          {
             buf_count *= 16; /* Retry with an arbitrarily scaled-up array */
           }
         new = dbus_realloc (buf, buf_count * sizeof (buf[0]));
@@ -1989,7 +1989,7 @@ fill_user_info (DBusUserInfo       *info,
             dbus_free (buf);
             goto failed;
           }
-        
+
         buf = new;
 
         errno = 0;
@@ -1999,7 +1999,7 @@ fill_user_info (DBusUserInfo       *info,
               {
                 _dbus_warn ("It appears that username \"%s\" is in more than %d groups.\nProceeding with just the first %d groups.",
                             username_c, buf_count, buf_count);
-              } 
+              }
             else
               {
                 dbus_set_error (error,
@@ -2021,12 +2021,12 @@ fill_user_info (DBusUserInfo       *info,
         dbus_free (buf);
         goto failed;
       }
-    
+
     for (i = 0; i < buf_count; ++i)
       info->group_ids[i] = buf[i];
 
     info->n_group_ids = buf_count;
-    
+
     dbus_free (buf);
   }
 #else  /* HAVE_GETGROUPLIST */
@@ -2046,9 +2046,9 @@ fill_user_info (DBusUserInfo       *info,
 #endif /* HAVE_GETGROUPLIST */
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   return TRUE;
-  
+
  failed:
   _DBUS_ASSERT_ERROR_IS_SET (error);
   return FALSE;
@@ -2121,7 +2121,7 @@ _dbus_credentials_add_from_current_process (DBusCredentials *credentials)
  * is required, that is done in dbus-auth.c. The username here
  * need not be anything human-readable, it can be the machine-readable
  * form i.e. a user id.
- * 
+ *
  * @param str the string to append to
  * @returns #FALSE on no memory
  */
@@ -2163,7 +2163,7 @@ _dbus_geteuid (void)
 /**
  * The only reason this is separate from _dbus_getpid() is to allow it
  * on Windows for logging but not for other purposes.
- * 
+ *
  * @returns process ID to put in log messages
  */
 unsigned long
@@ -2185,7 +2185,7 @@ _dbus_parse_uid (const DBusString      *uid_str,
 {
   int end;
   long val;
-  
+
   if (_dbus_string_get_length (uid_str) == 0)
     {
       _dbus_verbose ("UID string was zero length\n");
@@ -2200,7 +2200,7 @@ _dbus_parse_uid (const DBusString      *uid_str,
       _dbus_verbose ("could not parse string as a UID\n");
       return FALSE;
     }
-  
+
   if (end != _dbus_string_get_length (uid_str))
     {
       _dbus_verbose ("string contained trailing stuff after UID\n");
@@ -2250,7 +2250,7 @@ _dbus_atomic_dec (DBusAtomic *atomic)
   return __sync_sub_and_fetch(&atomic->value, 1)+1;
 #else
   dbus_int32_t res;
-  
+
   _DBUS_LOCK (atomic);
   res = atomic->value;
   atomic->value -= 1;
@@ -2303,7 +2303,7 @@ _dbus_poll (DBusPollFD *fds,
       _DBUS_STRUCT_OFFSET (struct pollfd, revents))
     {
       return poll ((struct pollfd*) fds,
-                   n_fds, 
+                   n_fds,
                    timeout_milliseconds);
     }
   else
@@ -2321,7 +2321,7 @@ _dbus_poll (DBusPollFD *fds,
   int i;
   struct timeval tv;
   int ready;
-  
+
   FD_ZERO (&read_set);
   FD_ZERO (&write_set);
   FD_ZERO (&err_set);
@@ -2340,7 +2340,7 @@ _dbus_poll (DBusPollFD *fds,
 
       max_fd = MAX (max_fd, fdp->fd);
     }
-    
+
   tv.tv_sec = timeout_milliseconds / 1000;
   tv.tv_usec = (timeout_milliseconds % 1000) * 1000;
 
@@ -2397,12 +2397,14 @@ _dbus_get_current_time (long *tv_sec,
  *
  * @param str the string to append to
  * @param filename filename to load
+ * @param mtime if not NULL the modification time will be stored here
  * @param error place to set an error
  * @returns #FALSE if error was set
  */
 dbus_bool_t
 _dbus_file_get_contents (DBusString       *str,
                          const DBusString *filename,
+                         unsigned long    *mtime,
                          DBusError        *error)
 {
   int fd;
@@ -2412,9 +2414,9 @@ _dbus_file_get_contents (DBusString       *str,
   const char *filename_c;
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   filename_c = _dbus_string_get_const_data (filename);
-  
+
   /* O_BINARY useful on Cygwin */
   fd = open (filename_c, O_RDONLY | O_BINARY);
   if (fd < 0)
@@ -2427,7 +2429,7 @@ _dbus_file_get_contents (DBusString       *str,
     }
 
   _dbus_verbose ("file fd %d opened\n", fd);
-  
+
   if (fstat (fd, &sb) < 0)
     {
       dbus_set_error (error, _dbus_error_from_errno (errno),
@@ -2437,9 +2439,9 @@ _dbus_file_get_contents (DBusString       *str,
 
       _dbus_verbose ("fstat() failed: %s",
                      _dbus_strerror (errno));
-      
+
       _dbus_close (fd, NULL);
-      
+
       return FALSE;
     }
 
@@ -2451,7 +2453,7 @@ _dbus_file_get_contents (DBusString       *str,
       _dbus_close (fd, NULL);
       return FALSE;
     }
-  
+
   total = 0;
   orig_len = _dbus_string_get_length (str);
   if (sb.st_size > 0 && S_ISREG (sb.st_mode))
@@ -2471,7 +2473,7 @@ _dbus_file_get_contents (DBusString       *str,
 
               _dbus_verbose ("read() failed: %s",
                              _dbus_strerror (errno));
-              
+
               _dbus_close (fd, NULL);
               _dbus_string_set_length (str, orig_len);
               return FALSE;
@@ -2479,9 +2481,6 @@ _dbus_file_get_contents (DBusString       *str,
           else
             total += bytes_read;
         }
-
-      _dbus_close (fd, NULL);
-      return TRUE;
     }
   else if (sb.st_size != 0)
     {
@@ -2492,11 +2491,13 @@ _dbus_file_get_contents (DBusString       *str,
       _dbus_close (fd, NULL);
       return FALSE;
     }
-  else
-    {
-      _dbus_close (fd, NULL);
-      return TRUE;
-    }
+
+
+  if (mtime)
+    *mtime = (unsigned long) sb.st_mtime;
+
+  _dbus_close (fd, NULL);
+  return TRUE;
 }
 
 /**
@@ -2523,11 +2524,11 @@ _dbus_string_save_to_file (const DBusString *str,
   dbus_bool_t retval;
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   fd = -1;
   retval = FALSE;
   need_unlink = FALSE;
-  
+
   if (!_dbus_string_init (&tmp_filename))
     {
       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
@@ -2540,7 +2541,7 @@ _dbus_string_save_to_file (const DBusString *str,
       _dbus_string_free (&tmp_filename);
       return FALSE;
     }
-  
+
   if (!_dbus_string_append (&tmp_filename, "."))
     {
       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
@@ -2555,7 +2556,7 @@ _dbus_string_save_to_file (const DBusString *str,
       _dbus_string_free (&tmp_filename);
       return FALSE;
     }
-    
+
   filename_c = _dbus_string_get_const_data (filename);
   tmp_filename_c = _dbus_string_get_const_data (&tmp_filename);
 
@@ -2570,9 +2571,9 @@ _dbus_string_save_to_file (const DBusString *str,
     }
 
   _dbus_verbose ("tmp file fd %d opened\n", fd);
-  
+
   need_unlink = TRUE;
-  
+
   total = 0;
   bytes_to_write = _dbus_string_get_length (str);
 
@@ -2588,7 +2589,7 @@ _dbus_string_save_to_file (const DBusString *str,
           dbus_set_error (error, _dbus_error_from_errno (errno),
                           "Could not write to %s: %s", tmp_filename_c,
                           _dbus_strerror (errno));
-          
+
           goto out;
         }
 
@@ -2614,7 +2615,7 @@ _dbus_string_save_to_file (const DBusString *str,
     }
 
   fd = -1;
-  
+
   if (rename (tmp_filename_c, filename_c) < 0)
     {
       dbus_set_error (error, _dbus_error_from_errno (errno),
@@ -2626,9 +2627,9 @@ _dbus_string_save_to_file (const DBusString *str,
     }
 
   need_unlink = FALSE;
-  
+
   retval = TRUE;
-  
+
  out:
   /* close first, then unlink, to prevent ".nfs34234235" garbage
    * files
@@ -2636,7 +2637,7 @@ _dbus_string_save_to_file (const DBusString *str,
 
   if (fd >= 0)
     _dbus_close (fd, NULL);
-        
+
   if (need_unlink && unlink (tmp_filename_c) < 0)
     _dbus_verbose ("Failed to unlink temp file %s: %s\n",
                    tmp_filename_c, _dbus_strerror (errno));
@@ -2645,7 +2646,7 @@ _dbus_string_save_to_file (const DBusString *str,
 
   if (!retval)
     _DBUS_ASSERT_ERROR_IS_SET (error);
-  
+
   return retval;
 }
 
@@ -2690,9 +2691,9 @@ _dbus_create_file_exclusively (const DBusString *filename,
   const char *filename_c;
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   filename_c = _dbus_string_get_const_data (filename);
-  
+
   fd = open (filename_c, O_WRONLY | O_BINARY | O_EXCL | O_CREAT,
              0600);
   if (fd < 0)
@@ -2706,7 +2707,7 @@ _dbus_create_file_exclusively (const DBusString *filename,
     }
 
   _dbus_verbose ("exclusive file fd %d opened\n", fd);
-  
+
   if (!_dbus_close (fd, NULL))
     {
       dbus_set_error (error,
@@ -2716,7 +2717,7 @@ _dbus_create_file_exclusively (const DBusString *filename,
                       _dbus_strerror (errno));
       return FALSE;
     }
-  
+
   return TRUE;
 }
 
@@ -2725,7 +2726,7 @@ _dbus_create_file_exclusively (const DBusString *filename,
  *
  * @param filename the filename
  * @param error error location
- * 
+ *
  * @returns #TRUE if unlink() succeeded
  */
 dbus_bool_t
@@ -2735,7 +2736,7 @@ _dbus_delete_file (const DBusString *filename,
   const char *filename_c;
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   filename_c = _dbus_string_get_const_data (filename);
 
   if (unlink (filename_c) < 0)
@@ -2764,14 +2765,14 @@ _dbus_create_directory (const DBusString *filename,
   const char *filename_c;
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   filename_c = _dbus_string_get_const_data (filename);
 
   if (mkdir (filename_c, 0700) < 0)
     {
       if (errno == EEXIST)
         return TRUE;
-      
+
       dbus_set_error (error, DBUS_ERROR_FAILED,
                       "Failed to create directory %s: %s\n",
                       filename_c, _dbus_strerror (errno));
@@ -2801,7 +2802,7 @@ _dbus_concat_dir_and_file (DBusString       *dir,
   if (_dbus_string_get_length (dir) == 0 ||
       _dbus_string_get_length (next_component) == 0)
     return TRUE;
-  
+
   dir_ends_in_slash = '/' == _dbus_string_get_byte (dir,
                                                     _dbus_string_get_length (dir) - 1);
 
@@ -2863,7 +2864,7 @@ _dbus_generate_pseudorandom_bytes (DBusString *str,
 {
   int old_len;
   char *p;
-  
+
   old_len = _dbus_string_get_length (str);
 
   if (!_dbus_string_lengthen (str, n_bytes))
@@ -2896,7 +2897,7 @@ _dbus_generate_random_bytes (DBusString *str,
    * a DBusError. So we always fall back to pseudorandom
    * if the I/O fails.
    */
-  
+
   old_len = _dbus_string_get_length (str);
   fd = -1;
 
@@ -2906,7 +2907,7 @@ _dbus_generate_random_bytes (DBusString *str,
     return _dbus_generate_pseudorandom_bytes (str, n_bytes);
 
   _dbus_verbose ("/dev/urandom fd %d opened\n", fd);
-  
+
   if (_dbus_read (fd, str, n_bytes) != n_bytes)
     {
       _dbus_close (fd, NULL);
@@ -2916,9 +2917,9 @@ _dbus_generate_random_bytes (DBusString *str,
 
   _dbus_verbose ("Read %d bytes from /dev/urandom\n",
                  n_bytes);
-  
+
   _dbus_close (fd, NULL);
-  
+
   return TRUE;
 }
 
@@ -2945,7 +2946,7 @@ const char*
 _dbus_strerror (int error_number)
 {
   const char *msg;
-  
+
   msg = strerror (error_number);
   if (msg == NULL)
     msg = "unknown";
@@ -2973,14 +2974,14 @@ void
 _dbus_fd_set_close_on_exec (int fd)
 {
   int val;
-  
+
   val = fcntl (fd, F_GETFD, 0);
-  
+
   if (val < 0)
     return;
 
   val |= FD_CLOEXEC;
-  
+
   fcntl (fd, F_SETFD, val);
 }
 
@@ -2996,7 +2997,7 @@ _dbus_close (int        fd,
              DBusError *error)
 {
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
  again:
   if (close (fd) < 0)
     {
@@ -3067,7 +3068,7 @@ _dbus_set_fd_nonblocking (int             fd,
   int val;
 
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-  
+
   val = fcntl (fd, F_GETFL, 0);
   if (val < 0)
     {
@@ -3100,17 +3101,17 @@ _dbus_set_fd_nonblocking (int             fd,
  */
 void
 _dbus_print_backtrace (void)
-{  
+{
 #if defined (HAVE_BACKTRACE) && defined (DBUS_BUILT_R_DYNAMIC)
   void *bt[500];
   int bt_size;
   int i;
   char **syms;
-  
+
   bt_size = backtrace (bt, 500);
 
   syms = backtrace_symbols (bt, bt_size);
-  
+
   i = 0;
   while (i < bt_size)
     {
@@ -3138,7 +3139,7 @@ _dbus_print_backtrace (void)
  * principle it could be in dbus-sysdeps-util.c, except that
  * dbus-sysdeps-util.c isn't in libdbus when tests are enabled and the
  * debug-pipe server is used.
- * 
+ *
  * @param fd1 return location for one end
  * @param fd2 return location for the other end
  * @param blocking #TRUE if pipe should be blocking
@@ -3190,20 +3191,20 @@ _dbus_full_duplex_pipe (int        *fd1,
     {
       dbus_set_error (error, _dbus_error_from_errno (errno),
                       "Could not set full-duplex pipe nonblocking");
-      
+
       _dbus_close (fds[0], NULL);
       _dbus_close (fds[1], NULL);
-      
+
       return FALSE;
     }
-  
+
   *fd1 = fds[0];
   *fd2 = fds[1];
 
   _dbus_verbose ("full-duplex pipe %d <-> %d\n",
                  *fd1, *fd2);
-  
-  return TRUE;  
+
+  return TRUE;
 #else
   _dbus_warn ("_dbus_full_duplex_pipe() not implemented on this OS\n");
   dbus_set_error (error, DBUS_ERROR_FAILED,
@@ -3229,7 +3230,7 @@ _dbus_printf_string_upper_bound (const char *format,
 }
 
 /**
- * Gets the temporary files directory by inspecting the environment variables 
+ * Gets the temporary files directory by inspecting the environment variables
  * TMPDIR, TMP, and TEMP in that order. If none of those are set "/tmp" is returned
  *
  * @returns location of temp directory
@@ -3260,9 +3261,9 @@ _dbus_get_tmpdir(void)
       if (tmpdir == NULL)
         tmpdir = "/tmp";
     }
-  
+
   _dbus_assert(tmpdir != NULL);
-  
+
   return tmpdir;
 }
 
@@ -3302,7 +3303,7 @@ _read_subprocess_line_argv (const char *progpath,
 
   dbus_bool_t retval;
   sigset_t new_set, old_set;
-  
+
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
   retval = FALSE;
 
@@ -3313,9 +3314,9 @@ _read_subprocess_line_argv (const char *progpath,
   sigemptyset (&new_set);
   sigaddset (&new_set, SIGCHLD);
   sigprocmask (SIG_BLOCK, &new_set, &old_set);
-  
+
   orig_len = _dbus_string_get_length (result);
-  
+
 #define READ_END        0
 #define WRITE_END       1
   if (pipe (result_pipe) < 0)
@@ -3360,7 +3361,7 @@ _read_subprocess_line_argv (const char *progpath,
         _exit (1);
 
       _dbus_verbose ("/dev/null fd %d opened\n", fd);
-      
+
       /* set-up stdXXX */
       close (result_pipe[READ_END]);
       close (errors_pipe[READ_END]);
@@ -3415,7 +3416,7 @@ _read_subprocess_line_argv (const char *progpath,
   errors_pipe[WRITE_END] = -1;
 
   ret = 0;
-  do 
+  do
     {
       ret = _dbus_read (result_pipe[READ_END], result, 1024);
     }
@@ -3455,7 +3456,7 @@ _read_subprocess_line_argv (const char *progpath,
     }
 
   retval = TRUE;
-  
+
  out:
   sigprocmask (SIG_SETMASK, &old_set, NULL);
 
@@ -3473,7 +3474,7 @@ _read_subprocess_line_argv (const char *progpath,
   if (errors_pipe[1] != -1)
     close (errors_pipe[1]);
 
-  return retval;  
+  return retval;
 }
 
 /**
@@ -3495,7 +3496,7 @@ _dbus_get_autolaunch_address (DBusString *address,
   int i;
   DBusString uuid;
   dbus_bool_t retval;
-  
+
   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
   retval = FALSE;
 
@@ -3504,13 +3505,13 @@ _dbus_get_autolaunch_address (DBusString *address,
       _DBUS_SET_OOM (error);
       return FALSE;
     }
-  
+
   if (!_dbus_get_local_machine_uuid_encoded (&uuid))
     {
       _DBUS_SET_OOM (error);
       goto out;
     }
-  
+
   i = 0;
   argv[i] = "dbus-launch";
   ++i;
@@ -3569,14 +3570,14 @@ _dbus_read_local_machine_uuid (DBusGUID   *machine_id,
 
 /**
  * Determines the address of the session bus by querying a
- * platform-specific method.  
+ * platform-specific method.
  *
  * The first parameter will be a boolean specifying whether
  * or not a dynamic session lookup is supported on this platform.
- * 
+ *
  * If supported is TRUE and the return value is #TRUE, the
  * address will be  appended to @p address.
- * If a failure happens, returns #FALSE and sets an error in 
+ * If a failure happens, returns #FALSE and sets an error in
  * @p error.
  *
  * If supported is FALSE, ignore the return value.
@@ -3593,15 +3594,15 @@ _dbus_lookup_session_address (dbus_bool_t *supported,
 {
   /* On non-Mac Unix platforms, if the session address isn't already
    * set in DBUS_SESSION_BUS_ADDRESS environment variable, we punt and
-   * fall back to the autolaunch: global default; see 
+   * fall back to the autolaunch: global default; see
    * init_session_address in dbus/dbus-bus.c. */
   *supported = FALSE;
   return TRUE;
 }
 
 /**
- * Returns the standard directories for a session bus to look for service 
- * activation files 
+ * Returns the standard directories for a session bus to look for service
+ * activation files
  *
  * On UNIX this should be the standard xdg freedesktop.org data directories:
  *
@@ -3613,10 +3614,10 @@ _dbus_lookup_session_address (dbus_bool_t *supported,
  * DBUS_DATADIR
  *
  * @param dirs the directory list we are returning
- * @returns #FALSE on OOM 
+ * @returns #FALSE on OOM
  */
 
-dbus_bool_t 
+dbus_bool_t
 _dbus_get_standard_session_servicedirs (DBusList **dirs)
 {
   const char *xdg_data_home;
@@ -3643,11 +3644,11 @@ _dbus_get_standard_session_servicedirs (DBusList **dirs)
         goto oom;
     }
 
-  /* 
+  /*
    * add configured datadir to defaults
    * this may be the same as an xdg dir
-   * however the config parser should take 
-   * care of duplicates 
+   * however the config parser should take
+   * care of duplicates
    */
   if (!_dbus_string_append (&servicedir_path, DBUS_DATADIR":"))
         goto oom;
@@ -3664,7 +3665,7 @@ _dbus_get_standard_session_servicedirs (DBusList **dirs)
 
       if (!_dbus_homedir_from_current_process (&homedir))
         goto oom;
-       
+
       if (!_dbus_string_append (&servicedir_path, _dbus_string_get_const_data (homedir)))
         goto oom;
 
@@ -3673,12 +3674,12 @@ _dbus_get_standard_session_servicedirs (DBusList **dirs)
         goto oom;
     }
 
-  if (!_dbus_split_paths_and_append (&servicedir_path, 
-                                     DBUS_UNIX_STANDARD_SESSION_SERVICEDIR, 
+  if (!_dbus_split_paths_and_append (&servicedir_path,
+                                     DBUS_UNIX_STANDARD_SESSION_SERVICEDIR,
                                      dirs))
     goto oom;
 
-  _dbus_string_free (&servicedir_path);  
+  _dbus_string_free (&servicedir_path);
   return TRUE;
 
  oom:
@@ -3688,8 +3689,8 @@ _dbus_get_standard_session_servicedirs (DBusList **dirs)
 
 
 /**
- * Returns the standard directories for a system bus to look for service 
- * activation files 
+ * Returns the standard directories for a system bus to look for service
+ * activation files
  *
  * On UNIX this should be the standard xdg freedesktop.org data directories:
  *
@@ -3702,10 +3703,10 @@ _dbus_get_standard_session_servicedirs (DBusList **dirs)
  * On Windows there is no system bus and this function can return nothing.
  *
  * @param dirs the directory list we are returning
- * @returns #FALSE on OOM 
+ * @returns #FALSE on OOM
  */
 
-dbus_bool_t 
+dbus_bool_t
 _dbus_get_standard_system_servicedirs (DBusList **dirs)
 {
   const char *xdg_data_dirs;
@@ -3730,21 +3731,21 @@ _dbus_get_standard_system_servicedirs (DBusList **dirs)
         goto oom;
     }
 
-  /* 
+  /*
    * add configured datadir to defaults
    * this may be the same as an xdg dir
-   * however the config parser should take 
-   * care of duplicates 
+   * however the config parser should take
+   * care of duplicates
    */
   if (!_dbus_string_append (&servicedir_path, DBUS_DATADIR":"))
         goto oom;
 
-  if (!_dbus_split_paths_and_append (&servicedir_path, 
-                                     DBUS_UNIX_STANDARD_SYSTEM_SERVICEDIR, 
+  if (!_dbus_split_paths_and_append (&servicedir_path,
+                                     DBUS_UNIX_STANDARD_SYSTEM_SERVICEDIR,
                                      dirs))
     goto oom;
 
-  _dbus_string_free (&servicedir_path);  
+  _dbus_string_free (&servicedir_path);
   return TRUE;
 
  oom:
@@ -3756,7 +3757,7 @@ _dbus_get_standard_system_servicedirs (DBusList **dirs)
  * Append the absolute path of the system.conf file
  * (there is no system bus on Windows so this can just
  * return FALSE and print a warning or something)
- * 
+ *
  * @param str the string to append to
  * @returns #FALSE if no memory
  */
@@ -3768,7 +3769,7 @@ _dbus_append_system_config_file (DBusString *str)
 
 /**
  * Append the absolute path of the session.conf file.
- * 
+ *
  * @param str the string to append to
  * @returns #FALSE if no memory
  */
@@ -3783,7 +3784,7 @@ _dbus_append_session_config_file (DBusString *str)
  * caches should be nuked. Of course any caches that need explicit reload
  * are probably broken, but c'est la vie.
  *
- * 
+ *
  */
 void
 _dbus_flush_caches (void)
@@ -3798,10 +3799,10 @@ _dbus_flush_caches (void)
  *
  * On UNIX the directory is ~/.dbus-keyrings while on Windows it should probably
  * be something else, since the dotfile convention is not normal on Windows.
- * 
+ *
  * @param directory string to append directory to
  * @param credentials credentials the directory should be for
- *  
+ *
  * @returns #FALSE on no memory
  */
 dbus_bool_t
@@ -3811,10 +3812,10 @@ _dbus_append_keyring_directory_for_credentials (DBusString      *directory,
   DBusString homedir;
   DBusString dotdir;
   dbus_uid_t uid;
-  
+
   _dbus_assert (credentials != NULL);
   _dbus_assert (!_dbus_credentials_are_anonymous (credentials));
-  
+
   if (!_dbus_string_init (&homedir))
     return FALSE;
 
@@ -3823,11 +3824,11 @@ _dbus_append_keyring_directory_for_credentials (DBusString      *directory,
 
   if (!_dbus_homedir_from_uid (uid, &homedir))
     goto failed;
-  
+
 #ifdef DBUS_BUILD_TESTS
   {
     const char *override;
-    
+
     override = _dbus_getenv ("DBUS_TEST_HOMEDIR");
     if (override != NULL && *override != '\0')
       {
@@ -3854,7 +3855,7 @@ _dbus_append_keyring_directory_for_credentials (DBusString      *directory,
   if (!_dbus_concat_dir_and_file (&homedir,
                                   &dotdir))
     goto failed;
-  
+
   if (!_dbus_string_copy (&homedir, 0,
                           directory, _dbus_string_get_length (directory))) {
     goto failed;
@@ -3862,8 +3863,8 @@ _dbus_append_keyring_directory_for_credentials (DBusString      *directory,
 
   _dbus_string_free (&homedir);
   return TRUE;
-  
- failed: 
+
+ failed:
   _dbus_string_free (&homedir);
   return FALSE;
 }