From: Junio C Hamano <gitster@pobox.com>
Date: Sun, 22 Feb 2026 20:36:28 GMT
Subject: Re: [PATCH] object-file: use `container_of()` to convert from base types
Message-ID: <xmqq8qckqzw3.fsf@gitster.g>
In-Reply-To: <20260222094158.GA1319383@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

> On Sat, Feb 21, 2026 at 11:07:08PM -0800, Junio C Hamano wrote:
>
>> Perhaps a fix-up patch on top of the topic branch like this?
>> 
>> ----- >8 -----
>> Subject: [PATCH] object-file.c: avoid container_of() of a NULL container
>> [...]
>>  static void prepare_loose_object_transaction(struct odb_transaction *base)
>>  {
>> -	struct odb_transaction_files *transaction =
>> -		container_of(base, struct odb_transaction_files, base);
>> +	struct odb_transaction_files *transaction = NULL;
>> +
>> +	if (base)
>> +		transaction =
>> +			container_of(base, struct odb_transaction_files, base);
>
> That works, but you can also use container_of_or_null() in the
> initializer. IMHO the result is easier to read.

Thanks.  Will use that.