Re: t5702 failing under ASan on master

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 31, 2019, 18:12 UTC
Message-ID: <xmqqsgx83ddx.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20190130114016.GD24387@genre.crustytoothpaste.net>

"brian m. carlson" <sandals@crustytoothpaste.net> writes:

Show 22 quoted lines

> On Wed, Jan 30, 2019 at 05:07:20PM +0700, Duy Nguyen wrote:
>> If I understand ASan report correctly alternate_shallow_file memory is
>> already gone after the first fetch, when we update the shallow file.
>> But we're doing two fetches in the same process (the tag backfill
>> thingy), the second fetch reuses the dangling alternate_shallow_file
>> pointer and ASan caught it. Resetting the variable seems like the
>> right way to go.
>
> Ah, I think I was missing the fact that we're doing a tag backfill. That
> explains a lot.
>
>> But should we reset it to an empty string? We would pass
>> "--shallow-file=" to "git index-pack", which is treated as "no shallow
>> file" (i.e. complete repo). This sounds wrong because this is still a
>> shallow repository.
>> 
>> I suppose setting alternate_shallow_file to NULL would be ok. "git
>> index-pack" will just go back to reading $GIT_DIR/info/shallow, which
>> has been updated and contains correct info.
>
> Yeah, that sounds like a better choice. I'll send a complete patch which
> does this.

Thanks, both.