Re: [PATCH v10 0/4] cat-file: add support for "-allow-unknown-type"

From: Eric Sunshine <sunshine@sunshineco.com>
Date: May 4, 2015, 03:30 UTC
Message-ID: <CAPig+cStUNPZqEyE1rJVj5AsTeZFU54mc97rgQqiPbr5V1B0Sw@mail.gmail.com>
In-Reply-To: <CAPig+cQKqkoqN+o_QfVBRvxGdNuJn_oxD5YMsvnBOHguimJhGQ@mail.gmail.com>

On Sun, May 3, 2015 at 10:55 PM, Eric Sunshine <sunshine@sunshineco.com> wrote:

Show 24 quoted lines

> On Sun, May 3, 2015 at 8:14 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> Junio C Hamano <gitster@pobox.com> writes:
>>
>>> Hmmmm... you do not seem to pass your own test.
>>>
>>> expecting success:
>>>         echo $bogus_type >expect &&
>>>         git cat-file -t --allow-unknown-type $bogus_sha1 >actual &&
>>>         test_cmp expect actual
>>>
>>> --- expect      2015-05-04 00:09:24.327335512 +0000
>>> +++ actual      2015-05-04 00:09:24.335335473 +0000
>>> @@ -1 +1 @@
>>> -abcdefghijklmnopqrstuvwxyz1234679
>>> +abcdefghijklmnopqrstuvwxyz123467abcdefghijklmnopqrstuvwxyz1234679
>>> not ok 86 - Type of broken object is correct when type is large
>>
>> Perhaps it would have a better chance of being correct with this
>> squashed in.
>
> Interestingly, neither test passes on Mac OS X even with this fixup.
> In fact, the git-hash-object invocation which computes/retrieves
> 'bogus_sha1' with the extra long bogus type crashes with SIGABRT in
> write_sha1_file_prepare(). Still investigating.

It's a buffer overflow problem. I'm preparing a patch.