tar: don't crash if getcwd fails

* src/extract.c: Don't include xgetcwd.h.
(extract_dir): stat "." rather than statting getcwd's output.
* src/misc.c (normalize_filename_x): Rewrite so as not to resolve
/../, which can't be done reliably in the presence of symlinks.
Don't reject valid names such as ".".
(normalize_filename): Don't make it absolute; that way, we don't
have to invoke xgetcwd which might fail.  Don't bother to realloc
at the end, since that uses time and now saves little space.
(chdir_do): Don't crash if xgetcwd fails.
* tests/Makefile.am (TESTSUITE_AT): Add listed03.at.
* tests/listed03.at: New file.
* tests/testsuite.at: Include listed03.at.

tests/Makefile.am

@@ -1,6 +1,6 @@
 # Makefile for GNU tar regression tests.
 
-# Copyright (C) 1996, 1997, 1999, 2000, 2001, 2003, 2004, 2005, 
+# Copyright (C) 1996, 1997, 1999, 2000, 2001, 2003, 2004, 2005,
 # 2006, 2007, 2009 Free Software Foundation, Inc.
 
 # François Pinard <pinard@iro.umontreal.ca>, 1988.
@@ -98,6 +98,7 @@ TESTSUITE_AT = \
  link03.at\
  listed01.at\
  listed02.at\
+ listed03.at\
  long01.at\
  longv7.at\
  lustar01.at\

tests/listed03.at

@@ -0,0 +1,45 @@
+# 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/>.
+
+# This checks for the --listed-incremental bug reported by J Chapman Flack at
+# http://lists.gnu.org/archive/html/bug-tar/2010-06/msg00000.html
+
+AT_SETUP([incremental dump when the parent directory is unreadable])
+AT_KEYWORDS([listed incremental listed03])
+
+AT_TAR_CHECK([
+mkdir dir
+mkdir dir/sub
+mkdir dir/sub/a
+genfile --file dir/sub/a/file
+cd dir/sub
+
+chmod a-r ..
+tar -c -f archive.tar --listed-incremental=db.1 -v a
+status=$?
+chmod a+r ..
+exit $status
+],
+[0],
+[a/
+a/file
+],
+[tar: a: Directory is new
+],[],[],[gnu])
+
+AT_CLEANUP

tests/testsuite.at

@@ -41,13 +41,13 @@ $1)],$2,$3,$4,$5,$6)
 m4_define([AT_TAR_WITH_HOOK],[
   m4_pushdef([AT_TAR_CHECK_HOOK],[$1])
   $2
-  
+
   m4_popdef([AT_TAR_CHECK_HOOK])])
 
 m4_define([TAR_IGNREC_HOOK],[
   AT_CHECK([grep -v '^.*tar: Record size = ' stderr; exit 0])
 ])
-  
+
 m4_define([RE_CHECK],[
 AT_DATA([$1.re],[$2])
 awk '{print NR " " $[]0}' $1 > $[]$.1
@@ -162,6 +162,7 @@ m4_include([incr01.at])
 m4_include([incr02.at])
 m4_include([listed01.at])
 m4_include([listed02.at])
+m4_include([listed03.at])
 m4_include([incr03.at])
 m4_include([incr04.at])
 m4_include([incr05.at])