Re: [Bug-tar] [GNU tar 1.24] empty dir and option -C

[Paul Eggert]

Thanks for that bug report.  This is a serious bug with tar -x -C,
and it suggests that we should generate a new version soon, alas.  I pushed
the following patch; please give it a try.  The only part you really
need is the one-line fix to src/extract.c; the rest of the patch is
to add a regression test for this bug.

---
tar: fix bug with -C and extracting directories

Problem reported by Denis Excoffier in
<http://lists.gnu.org/archive/html/bug-tar/2010-10/msg00034.html>.

* src/extract.c (extract_dir): Use mkdirat, not mkdir.
* tests/extrac16.at: New file, to test for this bug.
* tests/Makefile.am (TESTSUITE_AT): Add it.
* tests/testsuite.at: Include it.
---
 src/extract.c      |    2 +-
 tests/Makefile.am  |    1 +
 tests/extrac16.at  |   36 ++++++++++++++++++++++++++++++++++++
 tests/testsuite.at |    1 +
 4 files changed, 39 insertions(+), 1 deletions(-)
 create mode 100644 tests/extrac16.at

diff --git a/src/extract.c b/src/extract.c
index 0d23d4a..98236ac 100644
--- a/src/extract.c
+++ b/src/extract.c
@@ -777,7 +777,7 @@ extract_dir (char *file_name, int typeflag)
 
   for (;;)
     {
-      status = mkdir (file_name, mode);
+      status = mkdirat (chdir_fd, file_name, mode);
       if (status == 0)
        {
          current_mode = mode & ~ current_umask;
diff --git a/tests/Makefile.am b/tests/Makefile.am
index d29563a..b71e83c 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -82,6 +82,7 @@ TESTSUITE_AT = \
  extrac13.at\
  extrac14.at\
  extrac15.at\
+ extrac16.at\
  filerem01.at\
  filerem02.at\
  gzip.at\
diff --git a/tests/extrac16.at b/tests/extrac16.at
new file mode 100644
index 0000000..625e579
--- /dev/null
+++ b/tests/extrac16.at
@@ -0,0 +1,36 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+
+# Test suite for GNU tar.
+# Copyright (C) 2010 Free Software Foundation, Inc.
+
+# 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.
+
+# 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.
+
+# 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 Paul Eggert from a bug report by Denis Excoffier
+# <http://lists.gnu.org/archive/html/bug-tar/2010-10/msg00034.html>
+
+# Check extraction of empty directory with -C.
+
+AT_SETUP([extract empty directory with -C])
+AT_KEYWORDS([extract extrac16])
+
+AT_TAR_CHECK([
+mkdir src src/a src/a/b dest
+touch src/a/c
+
+tar -cf archive.tar -C src a &&
+tar -xf archive.tar -C dest
+],
+[0],[],[],[],[],[gnu])
+
+AT_CLEANUP
diff --git a/tests/testsuite.at b/tests/testsuite.at
index c386892..40f0e41 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -154,6 +154,7 @@ m4_include([extrac12.at])
 m4_include([extrac13.at])
 m4_include([extrac14.at])
 m4_include([extrac15.at])
+m4_include([extrac16.at])
 
 m4_include([label01.at])
 m4_include([label02.at])
-- 
1.7.2