git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Elijah Newren <newren@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Git Mailing List <git@vger.kernel.org>,
	Phillip Wood <phillip.wood@dunelm.org.uk>,
	Johannes Schindelin <johannes.schindelin@gmx.de>,
	Eric Sunshine <sunshine@sunshineco.com>
Subject: Re: [PATCH v3 5/7] git-rebase.txt: document behavioral inconsistencies between modes
Date: Thu, 21 Jun 2018 14:25:58 -0700	[thread overview]
Message-ID: <CABPp-BH5GYed+BBMadY869qGVpP7DDcD3HQtJSed_RPDVFJ-vA@mail.gmail.com> (raw)
In-Reply-To: <xmqqfu1fswdh.fsf@gitster-ct.c.googlers.com>

Hi Junio,

On Thu, Jun 21, 2018 at 1:44 PM, Junio C Hamano <gitster@pobox.com> wrote:
> Elijah Newren <newren@gmail.com> writes:
>
>> +BEHAVIORAL INCONSISTENCIES
>> +--------------------------
>> +
>> +  * --no-ff vs. --force-rebase
>
> Do we want to `--quote` these?

Ah, good point.

>> + * empty commits:
>> +
>> +    am-based rebase will drop any "empty" commits, whether the
>> +    commit started empty (had no changes relative to its parent to
>> +    start with) or ended empty (all changes were already applied
>> +    upstream in other commits).
>> +
>> +    merge-based rebase does the same.
>> +
>> +    interactive-based rebase will by default drop commits that
>> +    started empty and halt if it hits a commit that ended up empty.
>
> I think the description is accurate.
>
> WRT a change that ends up being empty (as opposed to a change that
> is empty from the beginning), I'd think that the current behaviour
> is desireable one.  "am" based rebase is solely to transplant an
> existing history and want to stop much less than "interactive" one
> whose purpose is to polish a series before making it publishable,
> and asking for confirmation ("this has become empty--do you want to
> drop it?") is more appropriate from the workflow point of view; so
> it may deserve s/inconsistencies/differences/.

Are you arguing the default for an explicit interactive rebase, or
also an implied one?

I would argue that implied interactive rebases also solely have the
purpose of "transplanting an existing history", as you say.  Thus, if
the user passes --rebase-merges (or --strategy or --strategy-options
after git-rebase--merge becomes part of git-rebase--interactive), then
the default should be the same as for am-based rebase, i.e. just
silently drop the empty commits.

>> +    The --keep-empty option exists for interactive rebases to allow
>> +    it to keep commits that started empty.
>
> On the other hand, lack of --keep-empty on the "am" side is probably
> a bug that wants to be fixed.

I personally don't like --keep-empty; it's too granular.  I'd prefer a
  --empty={drop,halt,keep}
flag, and have it apply to both patches that were empty when the
rebase started as well as patches that became empty after application
on the new base.  I think that'd be useful for both am-based and
interactive-based rebases.

Then we could also make an explicit --interactive flag imply
--empty=halt, if so desired, and otherwise make --empty=drop the
default.

I'm interested in implementing that, if other folks think it's not crazy.

Thoughts?

>> +  * empty commit messages:
>> +
>> +    am-based rebase will silently apply commits with empty commit
>> +    messages.
>> +
>> +    merge-based and interactive-based rebases will by default halt
>> +    on any such commits.  The --allow-empty-message option exists to
>> +    allow interactive-based rebases to apply such commits without
>> +    halting.
>
> Ditto for desirable difference coming from workflow point of view.

I can see the argument for having a difference for rebases if the
interactive rebase was explicit, though I disagree with the argument.
See https://public-inbox.org/git/CABPp-BHrcUHX_zHxpojV5=sxJ1=NoDg9uhxv+NH5BsHsQYavPQ@mail.gmail.com/
for my views on this.

However, I'm curious again -- is your argument only for
interactive_rebase=explicit or also for interactive_rebase=implied?

>> +  * directory rename detection:
>> +
>> +    merge-based and interactive-based rebases work fine with
>> +    directory rename detection.  am-based rebases sometimes do not.
>
> I quite do not get what the big deal is with "directory rename"; it
> is merely a degree of magic heuristics employed while detecting file
> renames.  It is natural to expect that the less information you make
> available to the machinery, the less amount of heuristics gets
> exercised to make "magic" happen.  Is the internal implementation
> detail described below (omitted) all that interesting to general
> readers of "git rebase --help", I wonder?  I would understand it if
> this were under Documentation/technical/, though.

You are right that the last two paragraphs are probably much too
technical and belong elsewhere; I can move them.  However, I am not
sure if you were requesting just those paragraphs be moved, or if you
wanted the whole "directory rename detection" section removed from the
manpage.  Could you clarify?  Also, if the latter...How would users
know how much "information is made available to the underlying
machinery", as you put it?  Or, at a higher level, what is the right
way to communicate to them how they can obtain a behavior they might
want (directory rename detection), if it's not mentioned somewhere in
the manpage?  Is there an alternate place to put this in the document?


Thanks,
Elijah

  reply	other threads:[~2018-06-21 21:26 UTC|newest]

Thread overview: 130+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-07  4:58 RFC: rebase inconsistency in 2.18 -- course of action? Elijah Newren
2018-06-07  5:04 ` [PATCH] t3401: add directory rename testcases for rebase and am Elijah Newren
2018-06-25 16:17   ` Elijah Newren
2018-06-07  5:05 ` [PATCH] apply: fix grammar error in comment Elijah Newren
2018-06-07  5:05 ` [PATCH] t5407: fix test to cover intended arguments Elijah Newren
2018-06-07  5:06 ` [PATCH] git-rebase--merge: modernize "git-$cmd" to "git $cmd" Elijah Newren
2018-06-07  5:24   ` Elijah Newren
2018-06-27  7:46   ` [PATCH v2] " Elijah Newren
2018-07-12 15:49     ` Johannes Schindelin
2018-07-13 16:13       ` Elijah Newren
2018-07-14 22:20         ` Johannes Schindelin
2018-06-07  5:06 ` [PATCH 1/2] t3422: new testcases for checking when incompatible options passed Elijah Newren
2018-06-07  5:06   ` [PATCH 2/2] git-rebase: error out " Elijah Newren
2018-06-10 19:40     ` Phillip Wood
2018-06-11 15:19       ` Elijah Newren
2018-06-11 15:59         ` Phillip Wood
2018-06-11 15:49       ` Elijah Newren
2018-06-12  9:45         ` Phillip Wood
2018-06-17  5:58   ` [RFC PATCH v2 0/7] Document/fix/warn about rebase incompatibilities and inconsistences Elijah Newren
2018-06-17  5:58     ` [RFC PATCH v2 1/7] git-rebase.txt: document incompatible options Elijah Newren
2018-06-17 15:38       ` Phillip Wood
2018-06-20 17:09         ` Elijah Newren
2018-06-17 17:15       ` Eric Sunshine
2018-06-20 17:10         ` Elijah Newren
2018-06-17  5:58     ` [RFC PATCH v2 2/7] git-rebase.sh: update help messages a bit Elijah Newren
2018-06-17  5:58     ` [RFC PATCH v2 3/7] t3422: new testcases for checking when incompatible options passed Elijah Newren
2018-06-17  5:58     ` [RFC PATCH v2 4/7] git-rebase: error out " Elijah Newren
2018-06-17  5:58     ` [RFC PATCH v2 5/7] git-rebase.txt: document behavioral inconsistencies between modes Elijah Newren
2018-06-17  5:58     ` [RFC PATCH v2 6/7] git-rebase.txt: address confusion between --no-ff vs --force-rebase Elijah Newren
2018-06-17  5:58     ` [RFC PATCH v2 7/7] git-rebase: make --allow-empty-message the default Elijah Newren
2018-06-17 15:30       ` Phillip Wood
2018-06-20 16:47         ` Elijah Newren
2018-06-17 15:41     ` [RFC PATCH v2 0/7] Document/fix/warn about rebase incompatibilities and inconsistences Phillip Wood
2018-06-21 15:00     ` [PATCH v3 0/7] Document/fix/warn about rebase incompatibilities and inconsistencies Elijah Newren
2018-06-21 15:00       ` [PATCH v3 1/7] git-rebase.txt: document incompatible options Elijah Newren
2018-06-21 19:47         ` Junio C Hamano
2018-06-21 20:33           ` Elijah Newren
2018-06-22  8:32         ` SZEDER Gábor
2018-06-21 15:00       ` [PATCH v3 2/7] git-rebase.sh: update help messages a bit Elijah Newren
2018-06-21 19:58         ` Junio C Hamano
2018-06-21 20:34           ` Elijah Newren
2018-06-21 15:00       ` [PATCH v3 3/7] t3422: new testcases for checking when incompatible options passed Elijah Newren
2018-06-21 20:04         ` Junio C Hamano
2018-06-21 20:37           ` Elijah Newren
2018-06-21 21:18           ` Eric Sunshine
2018-06-21 15:00       ` [PATCH v3 4/7] git-rebase: error out " Elijah Newren
2018-06-21 20:29         ` Junio C Hamano
2018-06-21 20:41           ` Elijah Newren
2018-06-21 15:00       ` [PATCH v3 5/7] git-rebase.txt: document behavioral inconsistencies between modes Elijah Newren
2018-06-21 20:44         ` Junio C Hamano
2018-06-21 21:25           ` Elijah Newren [this message]
2018-06-21 15:00       ` [PATCH v3 6/7] git-rebase.txt: address confusion between --no-ff vs --force-rebase Elijah Newren
2018-06-21 20:46         ` Junio C Hamano
2018-06-21 21:22           ` Elijah Newren
2018-06-21 15:00       ` [RFC PATCH v3 7/7] git-rebase: make --allow-empty-message the default Elijah Newren
2018-06-25 16:12       ` [PATCH v4 0/9] Document/fix/warn about rebase incompatibilities and inconsistencies Elijah Newren
2018-06-25 16:12         ` [PATCH v4 1/9] git-rebase.txt: document incompatible options Elijah Newren
2018-06-25 16:12         ` [PATCH v4 2/9] git-rebase.sh: update help messages a bit Elijah Newren
2018-06-25 16:12         ` [PATCH v4 3/9] t3422: new testcases for checking when incompatible options passed Elijah Newren
2018-06-26 18:17           ` Junio C Hamano
2018-06-27  6:50             ` Elijah Newren
2018-06-25 16:12         ` [PATCH v4 4/9] git-rebase: error out " Elijah Newren
2018-06-25 16:12         ` [PATCH v4 5/9] git-rebase.txt: address confusion between --no-ff vs --force-rebase Elijah Newren
2018-06-25 16:12         ` [PATCH v4 6/9] directory-rename-detection.txt: technical docs on abilities and limitations Elijah Newren
2018-06-25 16:12         ` [PATCH v4 7/9] git-rebase.txt: document behavioral differences between modes Elijah Newren
2018-06-25 16:12         ` [PATCH v4 8/9] t3401: add directory rename testcases for rebase and am Elijah Newren
2018-06-25 16:13         ` [RFC PATCH v4 9/9] git-rebase: make --allow-empty-message the default Elijah Newren
2018-06-27  7:23         ` [PATCH v5 0/9] Document/fix/warn about rebase incompatibilities and inconsistencies Elijah Newren
2018-06-27  7:23           ` [PATCH v5 1/9] git-rebase.txt: document incompatible options Elijah Newren
2018-06-27  7:23           ` [PATCH v5 2/9] git-rebase.sh: update help messages a bit Elijah Newren
2018-06-27  7:23           ` [PATCH v5 3/9] t3422: new testcases for checking when incompatible options passed Elijah Newren
2018-06-27  7:23           ` [PATCH v5 4/9] git-rebase: error out " Elijah Newren
2018-06-27  7:23           ` [PATCH v5 5/9] git-rebase.txt: address confusion between --no-ff vs --force-rebase Elijah Newren
2018-06-27  7:23           ` [PATCH v5 6/9] directory-rename-detection.txt: technical docs on abilities and limitations Elijah Newren
2018-06-27  7:23           ` [PATCH v5 7/9] git-rebase.txt: document behavioral differences between modes Elijah Newren
2018-06-27  7:23           ` [PATCH v5 8/9] t3401: add directory rename testcases for rebase and am Elijah Newren
2018-06-27  7:23           ` [RFC PATCH v5 9/9] git-rebase: make --allow-empty-message the default Elijah Newren
2018-09-12  2:42             ` 2.19.0 regression: leaving editor with empty commit message doesn't stop rebase [was: Re: [RFC PATCH v5 9/9] git-rebase: make --allow-empty-message the default] SZEDER Gábor
2018-09-12  6:21               ` Elijah Newren
2018-09-12 21:18               ` [PATCH] sequencer: fix --allow-empty-message behavior, make it smarter Elijah Newren
2018-09-13 20:24                 ` Junio C Hamano
2018-06-29 13:20           ` [PATCH v5 0/9] Document/fix/warn about rebase incompatibilities and inconsistencies Phillip Wood
2018-06-07  5:07 ` [PATCH] git-rebase.sh: handle keep-empty like all other options Elijah Newren
2018-06-10 19:26   ` Phillip Wood
2018-06-11 14:42     ` Elijah Newren
2018-06-11 15:16       ` Phillip Wood
2018-06-11 16:08         ` Elijah Newren
2018-06-12  9:53           ` Phillip Wood
2018-06-07  5:08 ` [PATCH 1/2] t3418: add testcase showing problems with rebase -i and strategy options Elijah Newren
2018-06-07  5:08   ` [PATCH 2/2] Fix use of strategy options with interactive rebases Elijah Newren
2018-06-27  7:36   ` [PATCH v2 0/2] " Elijah Newren
2018-06-27  7:36     ` [PATCH v2 1/2] t3418: add testcase showing problems with rebase -i and strategy options Elijah Newren
2018-06-27  7:45       ` Eric Sunshine
2018-06-27  7:49         ` Elijah Newren
2018-06-27 16:54           ` Junio C Hamano
2018-06-27 17:27             ` Elijah Newren
2018-06-27 18:17               ` Johannes Sixt
2018-06-27 18:24                 ` Eric Sunshine
2018-06-27 18:34                 ` [PATCH v2 1/2] t3418: add testcase showing problems with rebase SZEDER Gábor
2018-06-27 19:20                 ` [PATCH v2 1/2] t3418: add testcase showing problems with rebase -i and strategy options Junio C Hamano
2018-06-27 19:23               ` Junio C Hamano
2018-06-27  7:36     ` [PATCH v2 2/2] Fix use of strategy options with interactive rebases Elijah Newren
2018-06-27 15:48     ` [PATCH v3 0/2] " Elijah Newren
2018-06-27 15:48       ` [PATCH v3 1/2] t3418: add testcase showing problems with rebase -i and strategy options Elijah Newren
2018-06-27 18:28         ` SZEDER Gábor
2018-07-11 10:56           ` SZEDER Gábor
2018-07-11 19:12             ` Elijah Newren
2018-06-27 15:48       ` [PATCH v3 2/2] Fix use of strategy options with interactive rebases Elijah Newren
2018-07-12 15:41         ` Johannes Schindelin
2018-07-13 15:51           ` Elijah Newren
2018-06-07 17:13 ` [RFC PATCH 0/3] Send more rebases through interactive machinery Elijah Newren
2018-06-07 17:13   ` [RFC PATCH 1/3] git-rebase, sequencer: add a --quiet option for the " Elijah Newren
2018-06-09 21:45     ` Johannes Schindelin
2018-06-09 23:05       ` Elijah Newren
2018-06-07 17:13   ` [RFC PATCH 2/3] rebase: Implement --merge via git-rebase--interactive Elijah Newren
2018-06-09 22:04     ` Johannes Schindelin
2018-06-10  1:14       ` Elijah Newren
2018-06-11  9:54         ` Phillip Wood
2018-06-07 17:13   ` [RFC PATCH 3/3] git-rebase.sh: make git-rebase--interactive the default Elijah Newren
2018-06-09 22:11     ` Johannes Schindelin
2018-06-10  1:31       ` Elijah Newren
2018-06-17 21:44         ` Johannes Schindelin
2018-06-20 16:27           ` Elijah Newren
2018-06-21 10:57             ` Johannes Schindelin
2018-06-21 15:36               ` Elijah Newren
2019-01-21 15:55                 ` Johannes Schindelin
2019-01-21 19:02                   ` Elijah Newren
2019-01-22 15:37                     ` Johannes Schindelin
2018-06-11 17:44 ` RFC: rebase inconsistency in 2.18 -- course of action? Junio C Hamano
2018-06-11 20:17   ` Elijah Newren

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 \
    --in-reply-to=CABPp-BH5GYed+BBMadY869qGVpP7DDcD3HQtJSed_RPDVFJ-vA@mail.gmail.com \
    --to=newren@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=johannes.schindelin@gmx.de \
    --cc=phillip.wood@dunelm.org.uk \
    --cc=sunshine@sunshineco.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public 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).