# RFC: what should git rev-parse --flags HEAD do? 4 messages from 2010-09-25 to 2010-09-25. Participants: Jon Seymour, Junio C Hamano. Thread: https://gitlist.dev/t/25239 ## Jon Seymour, 2010-09-25 10:11 Subject: RFC: what should git rev-parse --flags HEAD do? Message-ID: URL: https://gitlist.dev/e/AANLkTimEToibgpUS1KTSruFRdggi3kbAJU5tfk9r6d2U%40mail.gmail.com ``` The documentation for git rev-parse --flags currently states: Do not output non-flag parameters. Therefore, one might expect: $ git rev-parse --flags HEAD to produce no output. In fact, it outputs the sha1 hash of HEAD. Can anyone see a reason why git rev-parse --flags should not be modified to match the documentation? If there is agreement that this should change, I can re-roll my current rev-parse series to include such a change. jon. ``` ## Junio C Hamano, 2010-09-25 17:54 Subject: Re: RFC: what should git rev-parse --flags HEAD do? Message-ID: <7vfwwxogiv.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7vfwwxogiv.fsf%40alter.siamese.dyndns.org In-Reply-To: ``` Jon Seymour writes: > The documentation for git rev-parse --flags currently states: > > Do not output non-flag parameters. > > Therefore, one might expect: > $ git rev-parse --flags HEAD > > to produce no output. > > In fact, it outputs the sha1 hash of HEAD. Perhaps you are missing --no-revs. Linus wrote rev-parse to implement this in a shell script: git log [other-options-and-args] [revision-traversal-options-and-args] which needs to be transformed to: git rev-list [revision-traversal-options-and-args] | git diff-tree --stdin [other-options-and-args] so that it can parse "-p HEAD" with and without "--no-revs" to produce "HEAD" and "-p" respectively. It does so by knowing options that are relevant to rev-list invocation (shown by default, or --revs-only) and everything else (hidden when --no-revs is given). "--flags" is an afterthought that filters out non-flags in other parts; I do not think it applied to the "rev" part (i.e. giving --no-revs at the same time would be a valid workaround if you know you do not want HEAD or any revision traversal argument) in any released version of git. ``` ## Jon Seymour, 2010-09-25 19:38 Subject: Re: RFC: what should git rev-parse --flags HEAD do? Message-ID: URL: https://gitlist.dev/e/AANLkTikW%3D4NiZ_jCq6geqta_XHiWJPUhWvvEtJ1Q3G9S%40mail.gmail.com In-Reply-To: <7vfwwxogiv.fsf@alter.siamese.dyndns.org> ``` On Sun, Sep 26, 2010 at 3:54 AM, Junio C Hamano wrote: > > Perhaps you are missing --no-revs. > ... > "--flags" is an afterthought that filters out non-flags in other parts; I > do not think it applied to the "rev" part (i.e. giving --no-revs at the > same time would be a valid workaround if you know you do not want HEAD or > any revision traversal argument) in any released version of git. > i am aware that --no-revs exists and can be used with --flags to ensure that only flag arguments are displayed. The issue is that the documentation currently implies that --flags alone is sufficient to suppress anything that is not a flag when this is not, in fact, the case. If there is some reason --flags should not imply --no-revs, then the documentation should be updated to state: --flags:: ``` ## Jon Seymour, 2010-09-25 19:46 Subject: Re: RFC: what should git rev-parse --flags HEAD do? Message-ID: URL: https://gitlist.dev/e/AANLkTim65zQp5Et2YQqk2ZZTuW-Dr0fJph%2B-8YZ0fDzw%40mail.gmail.com In-Reply-To: <7vfwwxogiv.fsf@alter.siamese.dyndns.org> ``` On Sun, Sep 26, 2010 at 3:54 AM, Junio C Hamano wrote: > > Perhaps you are missing --no-revs. > ... > "--flags" is an afterthought that filters out non-flags in other parts; I > do not think it applied to the "rev" part (i.e. giving --no-revs at the > same time would be a valid workaround if you know you do not want HEAD or > any revision traversal argument) in any released version of git. > i am aware that --no-revs exists and can be used with --flags to ensure that only flag arguments are displayed. The issue is that the documentation currently implies that --flags alone is sufficient to suppress anything that is not a flag when this is not, in fact, the case. To wit: --flags:: Do not output any non-flag parameters. This is simply not accurate, given the current implementation. If there is some reason --flags should not imply --no-revs, then the documentation should be updated to state: --flags:: Do not output any non-flag parameters (unless the parameter also specifies a revision). To output only the flag parameters, specify --no-revs as well. jon. ```