Re: tar on Mac does not like empty tar from git archive

["René Scharfe" <rene.scharfe@lsrfire.ath.cx>]

Am 08.04.2013 20:36, schrieb BJ Hargrave:
> Git 1.8.2.1 includes commit bd54cf17 - archive: handle commits with
> an empty tree
> 
> Test 2 of t5004-archive-corner-cases, "tar archive of empty tree is
> empty", fails on Mac OS X 10.8.3 (with XCode 4.6.1) since the tar
> command exits with return code 1 on the generated tar file.
> 
> expecting success:
> 	git archive --format=tar HEAD >empty.tar &&
> 	make_dir extract &&
> 	"$TAR" xf empty.tar -C extract &&
> 	check_dir extract
> 
> tar: Damaged tar archive
> tar: Error exit delayed from previous errors.
> not ok 2 - tar archive of empty tree is empty
> 
> tar tf "trash directory.t5004-archive-corner-cases/empty.tar"; echo $?
> tar: Damaged tar archive
> tar: Error exit delayed from previous errors.
> 1
> 
> tar --version
> bsdtar 2.8.3 - libarchive 2.8.3
> 
> It appears that bsdtar does not like the empty tar files created by
> git archive. An empty tar file created by bsdtar is accepted.
> 
> tar cT /dev/null | tar t; echo $?
> 0

I've opened an issue for libarchive for that behaviour:
http://code.google.com/p/libarchive/issues/detail?id=314

We can work around bsdtar's dislike of not-quite-empty tar archives by
leaving out the comment that contains the commit hash.

-- >8 --
Subject: t5004: fix issue with empty archive test and bsdtar

bsdtar, which is the default tar on Mac OS X, handles empty archives
just fine but reports archives containing only a pax extended header
comment as damaged.  Work around the issue by explicitly generating
the archive for the tree and not the commit, which causes git archive
to omit the commit hash comment record from the tar file.

Reported-by: BJ Hargrave <bj@bjhargrave.com>
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
---
 t/t5004-archive-corner-cases.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t5004-archive-corner-cases.sh b/t/t5004-archive-corner-cases.sh
index cdb7d7a..bfdb56a 100755
--- a/t/t5004-archive-corner-cases.sh
+++ b/t/t5004-archive-corner-cases.sh
@@ -28,7 +28,7 @@ check_dir() {
 }
 
 test_expect_success 'tar archive of empty tree is empty' '
-	git archive --format=tar HEAD >empty.tar &&
+	git archive --format=tar HEAD: >empty.tar &&
 	make_dir extract &&
 	"$TAR" xf empty.tar -C extract &&
 	check_dir extract
-- 
1.8.2.1