tar: fix bug with -C and delayed setting of metadata

* src/common.h (chdir_current): New decl.
* src/extract.c (struct delayed_set_stat, struct delayed_link):
New member change_dir.
(delay_set_stat, create_placeholder_file): Set it.
(apply_nonancestor_delayed_set_stat, apply_delayed_links): Use it.
(extract_link): Check that the links are all relative to the same
directory.
(extract_archive): Restore the current directory after
apply_nonancestor_delayed_set_stat has possibly changed it.
* src/misc.c (chdir_current): New external var; this used to
be the private static variable 'previous' inside chdir_dir.
All uses changed.
* tests/Makefile.am (TESTSUITE_AT): New test extrac10.at.
* tests/extrac10.at: New file.
* tests/testsuite.at: Include it.

tests/Makefile.am

@@ -76,6 +76,7 @@ TESTSUITE_AT = \
  extrac07.at\
  extrac08.at\
  extrac09.at\
+ extrac10.at\
  filerem01.at\
  filerem02.at\
  gzip.at\

tests/extrac10.at

@@ -0,0 +1,44 @@
+# 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
+
+# Check that delayed setting of directory metadata does not collide
+# with the -C option.  When setting a directory's permissions, time
+# stamps, etc., tar should apply the -C option that was in effect when
+# the directory was extracted, not the -C option that happens to be in
+# effect when the metadata are later set.
+
+AT_SETUP([-C and delayed setting of metadata])
+AT_KEYWORDS([extract extrac10])
+
+AT_TAR_CHECK([
+mkdir d x x/y
+echo foo >d/d1
+echo bar >e
+
+tar -cf archive.tar d e &&
+tar -xf archive.tar -C x d -C y e &&
+diff -r d x/d &&
+diff e x/y/e
+],
+[0],
+[],
+[],[],[],[gnu])
+
+AT_CLEANUP

tests/testsuite.at

@@ -148,6 +148,7 @@ m4_include([extrac06.at])
 m4_include([extrac07.at])
 m4_include([extrac08.at])
 m4_include([extrac09.at])
+m4_include([extrac10.at])
 
 m4_include([label01.at])
 m4_include([label02.at])