tar: port -d to longer symlinks

[chaz/tar] / src / compare.c

diff --git a/src/compare.c b/src/compare.c
index 0e99a7201cadf528bf57f1dc866c68c35091146c..7ed455848791cd40433dd52aea4b17155e970b3b 100644 (file)
--- a/src/compare.c
+++ b/src/compare.c
@@ -1,24 +1,24 @@
 /* Diff files from a tar archive.
 
-   Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1999, 2000, 2001,
-   2003, 2004, 2005, 2006, 2007, 2009, 2010, 2012 Free Software
-   Foundation, Inc.
+   Copyright 1988, 1992-1994, 1996-1997, 1999-2001, 2003-2007,
+   2009-2010, 2012-2014 Free Software Foundation, Inc.
 
-   Written by John Gilmore, on 1987-04-30.
+   This file is part of GNU tar.
 
-   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 3, or (at your option) any later
-   version.
+   GNU tar 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 3 of the License, or
+   (at your option) any later version.
 
-   This program is distributed in the hope that it will be useful, 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.
+   GNU tar is distributed in the hope that it will be useful,
+   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.  */
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+   Written by John Gilmore, on 1987-04-30.  */
 
 #include <system.h>
 #include <system-ioctl.h>
@@ -270,11 +270,12 @@ diff_link (void)
 static void
 diff_symlink (void)
 {
+  char buf[1024];
   size_t len = strlen (current_stat_info.link_name);
-  char *linkbuf = alloca (len + 1);
+  char *linkbuf = len < sizeof buf ? buf : xmalloc (len + 1);
 
-  int status = readlinkat (chdir_fd, current_stat_info.file_name,
-                          linkbuf, len + 1);
+  ssize_t status = readlinkat (chdir_fd, current_stat_info.file_name,
+                              linkbuf, len + 1);
 
   if (status < 0)
     {
@@ -285,8 +286,11 @@ diff_symlink (void)
       report_difference (&current_stat_info, NULL);
     }
   else if (status != len
-          || strncmp (current_stat_info.link_name, linkbuf, len) != 0)
+          || memcmp (current_stat_info.link_name, linkbuf, len) != 0)
     report_difference (&current_stat_info, _("Symlink differs"));
+
+  if (linkbuf != buf)
+    free (linkbuf);
 }
 #endif
 
@@ -371,7 +375,10 @@ diff_dumpdir (struct tar_stat_info *dir)
       if (fd < 0)
        diag = open_diag;
       else if (fstat (fd, &dir->stat))
-       diag = stat_diag;
+        {
+         diag = stat_diag;
+          close (fd);
+        }
       else
        dir->fd = fd;
       if (diag)
@@ -439,10 +446,9 @@ diff_multivol (void)
     {
       seek_error_details (current_stat_info.file_name, offset);
       report_difference (&current_stat_info, NULL);
-      return;
     }
-
-  read_and_process (&current_stat_info, process_rawdata);
+  else
+    read_and_process (&current_stat_info, process_rawdata);
 
   status = close (fd);
   if (status != 0)