From: Jeff King <peff@peff.net>
Date: Sun, 22 Feb 2026 09:41:58 GMT
Subject: Re: [PATCH] object-file: use `container_of()` to convert from base types
Message-ID: <20260222094158.GA1319383@coredump.intra.peff.net>
In-Reply-To: <xmqqms11qmsj.fsf@gitster.g>

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.

-Peff