From fc58a8bd984eb5334f713ec7ac993bddfe9e77d3 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Tue, 29 Apr 2014 14:22:07 -0700
Subject: [PATCH] tar: do not dereference NULL pointer with '--remove-files .'

Problem reported by Thorsten Hirsch in:
http://lists.gnu.org/archive/html/bug-tar/2014-04/msg00011.html
* src/unlink.c (flush_deferred_unlinks):
Do not attempt to find the parent of "." when "." is
at the top level.
* tests/remfiles10.at: New file.
* tests/Makefile.am (TESTSUITE_AT):
* tests/testsuite.at: Add it.
---
 src/unlink.c        |  9 +++++----
 tests/Makefile.am   |  1 +
 tests/remfiles10.at | 46 +++++++++++++++++++++++++++++++++++++++++++++
 tests/testsuite.at  |  1 +
 4 files changed, 53 insertions(+), 4 deletions(-)
 create mode 100644 tests/remfiles10.at

diff --git a/src/unlink.c b/src/unlink.c
index 225d49b..7f86cc5 100644
--- a/src/unlink.c
+++ b/src/unlink.c
@@ -73,7 +73,7 @@ flush_deferred_unlinks (bool force)
 {
   struct deferred_unlink *p, *prev = NULL;
   int saved_chdir = chdir_current;
-  
+
   for (p = dunlink_head; p; )
     {
       struct deferred_unlink *next = p->next;
@@ -86,15 +86,16 @@ flush_deferred_unlinks (bool force)
 	    {
 	      const char *fname;
 
-	      if (p->file_name[0] == 0 ||
-		  strcmp (p->file_name, ".") == 0)
+	      if (p->dir_idx
+		  && (p->file_name[0] == 0
+		      || strcmp (p->file_name, ".") == 0))
 		{
 		  fname = tar_dirname ();
 		  chdir_do (p->dir_idx - 1);
 		}
 	      else
 		fname = p->file_name;
-		  
+
 	      if (unlinkat (chdir_fd, fname, AT_REMOVEDIR) != 0)
 		{
 		  switch (errno)
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 3896b72..fd2def5 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -187,6 +187,7 @@ TESTSUITE_AT = \
  remfiles09a.at\
  remfiles09b.at\
  remfiles09c.at\
+ remfiles10.at\
  same-order01.at\
  same-order02.at\
  shortfile.at\
diff --git a/tests/remfiles10.at b/tests/remfiles10.at
new file mode 100644
index 0000000..b4fe139
--- /dev/null
+++ b/tests/remfiles10.at
@@ -0,0 +1,46 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+# Test suite for GNU tar.
+# Copyright 2014 Free Software Foundation, Inc.
+#
+# 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.
+#
+# 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, see <http://www.gnu.org/licenses/>.
+
+# Check --remove-files with .
+
+AT_SETUP([remove-files])
+AT_KEYWORDS([create remove-files remfiles10])
+
+AT_TAR_CHECK([
+mkdir foo
+echo foo/file > foo/file
+decho A
+(cd foo && tar -cvf ../foo.tar --remove-files .)
+tar_status=$?
+decho B
+find foo
+exit $tar_status
+],
+[2],
+[A
+./
+./file
+B
+foo
+],
+[A
+tar: .: Cannot rmdir: Invalid argument
+tar: Exiting with failure status due to previous errors
+B
+],[],[],[gnu])
+
+AT_CLEANUP
diff --git a/tests/testsuite.at b/tests/testsuite.at
index 3096e0d..7f8e4c4 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -399,6 +399,7 @@ m4_include([remfiles08c.at])
 m4_include([remfiles09a.at])
 m4_include([remfiles09b.at])
 m4_include([remfiles09c.at])
+m4_include([remfiles10.at])
 
 AT_BANNER([Extended attributes])
 m4_include([xattr01.at])
-- 
2.43.0