From: Junio C Hamano <email@example.com> To: Jeff King <firstname.lastname@example.org> Cc: email@example.com Subject: Re: [PATCH 4/4] describe/name-rev: tell name-rev to peel the incoming object to commit first Date: Tue, 09 Jul 2013 04:45:39 -0700 [thread overview] Message-ID: <firstname.lastname@example.org> (raw) In-Reply-To: <20130709053533.GA4395@sigill.intra.peff.net> (Jeff King's message of "Tue, 9 Jul 2013 01:35:33 -0400") Jeff King <email@example.com> writes: > Although I am still not clear on why it would not be up to the caller of > git-describe in the first place to decide which they wanted. Thanks for a dose of sanity. Even though the part of the miniseries that makes sure that "X (Y)" output from "name-rev" always satisfies that "rev-parse" on X and Y give the same thing is an improvement, the whole thing about "describe" is misguided and wrong, I think. It started from the observation that these do not match: $ git describe $(git rev-parse v1.8.3) v1.8.3 $ git describe --contains $(git rev-parse v1.8.3) v1.8.3^0 and the miniseries veered in a wrong direction of "fixing" the latter to match the former. But the thing is, what is incosistent from the rest of the world is the describe output without "--contains" for a commit that is exactly at a tag (i.e. the former), and there is no need to "fix" this "inconsistency", as we see below. The form without "--contains" in general reads like this: $ git describe --long $(git rev-parse v1.8.3) a717d9e v1.8.3-0-gedca415 v1.8.3-2-ga717d9e They both name a commit object, but that is sort of an afterthought; the support for describe name came late at 7dd45e15 (sha1_name.c: understand "describe" output as a valid object name, 2006-09-20). The primary purpose of "git describe" without "--contains" is to give a string that is suitable for a version number to be embedded in an executable. For that purpose, "v1.8.3" is more convenient than "v1.8.3-0-gedca415". But this convenient format breaks the consistency. While any other describe name for a commmit names a commit, the output for a commit that is exactly at a tag does not (in ancient times, describe output were not even extended SHA-1 expressions, so this inconsistency did not matter, but the "afterthought" brought the consistency to the foreground). The user chooses the convenience over the consistency by not using "--long". And the short form cannot be "v1.8.3^0" or "v1.8.3~0" for the sake of "consistency", as these are no more suitable as a version number than a short and sweet "v1.8.3". The "--contains" form does not even aim to come up with a pleasant looking version string without using funny line noise characters, so it is perfectly fine for it to say: $ git describe --contains $(git rev-parse v1.8.3) a717d9e v1.8.3^0 v22.214.171.124~9 and these are internally consistent (they both roundtrip via rev-parse). Stripping "^0" from the former will break the consistency, even though it may make the output look prettier, but the "--contains" output is not even meant to be "pretty" in the first place. So let's drop 4/4; it is breaking the system by trying to solve a problem that does not exist.
next prev parent reply other threads:[~2013-07-09 11:45 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-07-07 22:33 [PATCH 0/4] Make "git name-rev $(git rev-parse v1.8.3)" work Junio C Hamano 2013-07-07 22:33 ` [PATCH 1/4] name-ref: factor out name shortening logic from name_ref() Junio C Hamano 2013-07-08 8:52 ` Michael Haggerty 2013-07-08 15:04 ` Junio C Hamano 2013-07-07 22:33 ` [PATCH 2/4] name-rev: allow converting the exact object name at the tip of a ref Junio C Hamano 2013-07-08 12:20 ` Ramkumar Ramachandra 2013-07-08 15:12 ` Junio C Hamano 2013-07-07 22:33 ` [PATCH 3/4] describe: use argv-array Junio C Hamano 2013-07-09 4:51 ` Jeff King 2013-07-09 14:55 ` Junio C Hamano 2013-07-09 16:00 ` Junio C Hamano 2013-07-09 18:53 ` Jeff King 2013-07-07 22:33 ` [PATCH 4/4] describe/name-rev: tell name-rev to peel the incoming object to commit first Junio C Hamano 2013-07-08 13:08 ` Ramkumar Ramachandra 2013-07-09 5:12 ` Jeff King 2013-07-09 5:06 ` Jeff King 2013-07-09 5:33 ` Junio C Hamano 2013-07-09 5:35 ` Jeff King 2013-07-09 11:45 ` Junio C Hamano [this message] 2013-07-09 12:42 ` Ramkumar Ramachandra
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style List information: http://vger.kernel.org/majordomo-info.html * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --subject='Re: [PATCH 4/4] describe/name-rev: tell name-rev to peel the incoming object to commit first' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Code repositories for project(s) associated with this inbox: https://80x24.org/mirrors/git.git This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).