Re: [PATCH] t: add clone test for files differing only in case

From: Duy Nguyen <pclouds@gmail.com>
Date: Jan 21, 2018, 11:50 UTC
Message-ID: <CACsJy8CpfVb546caxP-HGjk9uXa805uayF0A7oMzh+fzEFS_Qw@mail.gmail.com>
In-Reply-To: <20180120203324.112522-1-sandals@crustytoothpaste.net>

On Sun, Jan 21, 2018 at 3:33 AM, brian m. carlson <sandals@crustytoothpaste.net> wrote:

Show 18 quoted lines

> We recently introduced a regression in cloning repositories onto
> case-insensitive file systems where the repository contains multiple
> files differing only in case.  In such a case, we would segfault.  This
> segfault has already been fixed (repository: pre-initialize hash algo
> pointer), but it's not the first time similar problems have arisen.
> Introduce a test to catch this case and ensure the behavior does not
> regress.
>
> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
> Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
> ---
>  t/t5601-clone.sh | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> I've verified that the test does fail without the patch on a vfat file
> system.  However, many other tests also fail on a vfat file system on
> Linux, so unfortunately that doesn't look like a viable testing strategy
> going forward.

vfat is not very UNIXy. I suspect we need a bunch of tweaks that cygwin/mingw uses to make the test suite pass. There are other case-insensitive filesystems on linux though. JFS (with "mkfs.jfs -O" to make it case-insensitive) seems to pass the test suite and crash git without your fix so it's a good candidate if someone wants to test this behavior on linux in future. HFS+ fails some unicode test in t0050 and I didn't check further.

> +test_expect_success 'clone on case-insensitive fs' '

We have CASE_INSENSITIVE_FS prereq. Should we use it here? I know it does not harm running this test on case-sensitive filesystem, but the prereq could be useful for grepping.

Show 9 quoted lines

> +       o=$(git hash-object -w --stdin </dev/null | hex2oct) &&
> +       t=$(printf "100644 X\0${o}100644 x\0${o}" |
> +               git hash-object -w -t tree --stdin) &&
> +       c=$(git commit-tree -m bogus $t) &&
> +       git update-ref refs/heads/bogus $c &&
> +       git clone -b bogus . bogus
> +'
> +
>  test_done

-- 
Duy