>From 3281269662a7d361ef8a360600352e93cc2ebdcf Mon Sep 17 00:00:00 2001
From: Pavel Raiskup <address@hidden>
Date: Mon, 25 Feb 2013 10:18:15 +0100
Subject: [PATCH] tar: The Lempel-Ziv coding bugfix

Do not exit with fatal error 2 after compressing tarball by the
'compress' utility (-Z option) when the child process running the
compressor exited with "just-a-warning" exit value 2.  There is still
possible to restore the old tar behavior by running
'./configure --without-compress-exit-hack' (e.g. in situations when
there resides different compress implementation on the target system).

* acinclude.m4 (TAR_COMPRESS_EXIT_HACK): New function.
* configure.ac: Use TAR_COMPRESS_EXIT_HACK.
* src/system.c (sys_wait_for_child) [#ifdef HAVE_COMPRESS_EXIT_HACK]:
Warn when the compressed data are larger then the original data if
the child process command exited with 2 while the compressing
command was called 'compress'.
* NEWS: Document.
---
 NEWS         |  7 +++++++
 acinclude.m4 | 19 +++++++++++++++++++
 configure.ac |  3 +++
 src/system.c |  7 +++++++
 4 files changed, 36 insertions(+)

diff --git a/NEWS b/NEWS
index 3108798..863cf52 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,13 @@ version 1.26.90 (Git)
 
 * Bug fixes
 
+** The Lempel-Ziv coding compression bugfix (compress)
+
+Do not exit with fatal error during compressing by the 'compress'
+utility (-Z option) when the child process running the compressor exits
+with "warning" exit value 2.  It just means that the compressed output is
+bigger then original data.  Just warn the user now instead of hard fail.
+
 ** Sparse files with large data
 
 When creating a PAX-format archive, tar no longer arbitrarily restricts
diff --git a/acinclude.m4 b/acinclude.m4
index d48c881..1367eed 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -52,3 +52,22 @@ AC_DEFUN([TAR_HEADERS_ATTR_XATTR_H],
     )
   fi
 ])
+
+# Allow maintainer to disable compress's exit-2-value hack
+AC_DEFUN([TAR_COMPRESS_EXIT_HACK],[
+  AC_ARG_WITH(
+    [compress-exit-hack],
+    AS_HELP_STRING(
+      [--without-compress-exit-hack],
+      [fail when -Z (compress) compressor exists with non-error value 2]),
+    [with_compress_exit_hack=no]
+  )
+  if test "x$with_compress_exit_hack" != xno; then
+    AC_DEFINE_UNQUOTED(
+      HAVE_COMPRESS_EXIT_HACK,
+      "$tar_cv_compressor_compress",
+      Define to name of compress utility when we don't want to fail hardly
+      if this utility exits with exit code 2.  It should just mean that the
+      compressed file is bigger than original file.)
+  fi
+])
diff --git a/configure.ac b/configure.ac
index 3303c53..b0a4f14 100644
--- a/configure.ac
+++ b/configure.ac
@@ -253,6 +253,9 @@ TAR_COMPR_PROGRAM(lzma)
 TAR_COMPR_PROGRAM(lzop)
 TAR_COMPR_PROGRAM(xz)
 
+# must be called after TAR_COMPR_PROGRAM(compress) call
+TAR_COMPRESS_EXIT_HACK
+
 AC_MSG_CHECKING(for default archive format)
 
 AC_ARG_VAR([DEFAULT_ARCHIVE_FORMAT],
diff --git a/src/system.c b/src/system.c
index e1fd263..d722352 100644
--- a/src/system.c
+++ b/src/system.c
@@ -189,6 +189,13 @@ sys_wait_for_child (pid_t child_pid, bool eof)
 	  if (!(!eof && sig == SIGPIPE))
 	    FATAL_ERROR ((0, 0, _("Child died with signal %d"), sig));
 	}
+#ifdef HAVE_COMPRESS_EXIT_HACK
+      else if (!strcmp (use_compress_program_option, HAVE_COMPRESS_EXIT_HACK)
+	       && WEXITSTATUS (wait_status) == 2)
+        WARN ((0, 0, _("%lu: Child says that compressed output is larger "
+		       "then original data."),
+	       (unsigned long) child_pid));
+#endif
       else if (WEXITSTATUS (wait_status) != 0)
 	FATAL_ERROR ((0, 0, _("Child returned status %d"),
 		      WEXITSTATUS (wait_status)));
-- 
1.8.1.2