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From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Patrick Steinhardt <ps@pks.im>,
	 Yasushi SHOJI <yasushi.shoji@gmail.com>,
	 Denton Liu <liu.denton@gmail.com>,
	 Git Mailing List <git@vger.kernel.org>
Subject: Re: [PATCH 3/3] read_ref_at(): special-case ref@{0} for an empty reflog
Date: Mon, 26 Feb 2024 09:25:28 -0800	[thread overview]
Message-ID: <xmqqmsrncf3r.fsf@gitster.g> (raw)
In-Reply-To: <20240226100803.GC2685600@coredump.intra.peff.net> (Jeff King's message of "Mon, 26 Feb 2024 05:08:03 -0500")

Jeff King <peff@peff.net> writes:

>  	if (!cb.reccnt) {
> +		if (cnt == 0) {

Style "if (!cnt)" ?  In this particular case I do not think it
actually is an improvement, though, simply because zero is really
special in this logic.

> +			/*
> +			 * The caller asked for ref@{0}, and we had no entries.
> +			 * It's a bit subtle, but in practice all callers have
> +			 * prepped the "oid" field with the current value of
> +			 * the ref, which is the most reasonable fallback.
> +			 *
> +			 * We'll put dummy values into the out-parameters (so
> +			 * they're not just uninitialized garbage), and the
> +			 * caller can take our return value as a hint that
> +			 * we did not find any such reflog.
> +			 */
> +			set_read_ref_cutoffs(&cb, 0, 0, "empty reflog");
> +			return 1;
> +		}

The dummy value I 100% agree with ;-).

You mentioned the convenience special case for time-based reflog
query for a time older than (e.g. @{20.years.ago}) the reflog
itself, and perhaps this one should be treated as its counterpart,
that is only useful for count-based access.


  parent reply	other threads:[~2024-02-26 17:25 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-21  1:48 Segfault: git show-branch --reflog refs/pullreqs/1 Yasushi SHOJI
2024-02-21  8:42 ` Jeff King
2024-02-21 10:05   ` Patrick Steinhardt
2024-02-21 17:38     ` Jeff King
2024-02-21 17:44   ` Junio C Hamano
2024-02-22  9:02     ` Patrick Steinhardt
2024-02-22 16:32       ` Junio C Hamano
2024-02-22 17:22         ` Jeff King
2024-02-26 10:00           ` [PATCH 0/3] show-branch --reflog fixes Jeff King
2024-02-26 10:02             ` [PATCH 1/3] Revert "refs: allow @{n} to work with n-sized reflog" Jeff King
2024-02-26 10:04             ` [PATCH 2/3] get_oid_basic(): special-case ref@{n} for oldest reflog entry Jeff King
2024-02-26 15:59               ` Junio C Hamano
2024-02-26 10:08             ` [PATCH 3/3] read_ref_at(): special-case ref@{0} for an empty reflog Jeff King
2024-02-26 10:10               ` Jeff King
2024-02-26 17:25                 ` Junio C Hamano
2024-02-27  8:07                   ` Jeff King
2024-02-26 17:25               ` Junio C Hamano [this message]
2024-02-27  8:05                 ` Jeff King
2024-02-27 17:03                   ` Junio C Hamano
2024-02-21  9:52 ` Segfault: git show-branch --reflog refs/pullreqs/1 Patrick Steinhardt
2024-02-21  9:56 ` [PATCH 0/2] Detect empty or missing reflogs with `ref@{0}` Patrick Steinhardt
2024-02-21  9:56   ` [PATCH 1/2] object-name: detect and report empty reflogs Patrick Steinhardt
2024-02-21 10:37     ` Kristoffer Haugsbakk
2024-02-21 16:48     ` Eric Sunshine
2024-02-21 17:31     ` Jeff King
2024-02-21  9:56   ` [PATCH 2/2] builtin/show-branch: detect " Patrick Steinhardt
2024-02-21 17:35     ` Jeff King

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