From: Junio C Hamano <gitster@pobox.com>
Date: Sat, 23 Nov 2019 02:03:42 GMT
Subject: Re: [PATCH v2 1/1] sequencer: fix empty commit check when amending
Message-ID: <xmqq5zjb2vsx.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <037f2b2975e06847443aef46939e3c712053dedf.1574451783.git.gitgitgadget@gmail.com>

"Phillip Wood via GitGitGadget" <gitgitgadget@gmail.com> writes:

> +	if (!(flags & ALLOW_EMPTY)) {
> +		struct commit *first_parent = current_head;
> +
> +		if (flags & AMEND_MSG) {
> +			if (current_head->parents) {

It is not apparent to me that somebody guarantees that this access
is safe; would we need to do things differently when !current_head?

> +				first_parent = current_head->parents->item;
> +				if (repo_parse_commit(r, first_parent)) {
> +					res = error(_("could not parse HEAD commit"));
> +					goto out;
> +				}
> +			} else {
> +				first_parent = NULL;
> +			}
> +		}