mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Igor Djordjevic <>
To:, Alexei Lozovsky <>
Cc: Junio C Hamano <>, Johannes Sixt <>,
	Git Mailing List <>,
	Nikolay Shustov <>,
	Johannes Schneider <>,
	Patrik Gornicz <>,
	Martin Waitz <>,
	Shawn Pearce <>, Sam Vilain <>,
	Jakub Narebski <>
Subject: Re: [SCRIPT/RFC 0/3] git-commit --onto-parent (three-way merge, noworking tree file changes)
Date: Sun, 10 Dec 2017 02:20:12 +0100	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

Hi Philip,

On 09/12/2017 20:01, Phillip Wood wrote:
> > But thanks for clarifying, anyway, it does feel like `git rebase
> > -i --autosquash` could be smarter in this regards, if `git rebase 
> > --onto` does it better...?
> Creating the fixup directly on A rather than on top of B avoids the 
> conflicting merge B f!A A. Creating the fixup on top of B and then
> using git commit --onto A would suffer from the same conflicts as
> rebase does.

I`m a bit confused here, as you`re replying to the part where we 
strictly discussed `rebase --autosquash` versus `rebase --onto`, 
having the latter succeed where the former fails - but you`re 
mentioning `git _commit_ --onto` instead, comparing it with `rebase`... 
and which one of the two ("--autosquash", I assume)?

Even further, while I do seem to understand (and agree with) what 
you`re talking about with `commit --onto` and `rebase --autosquah` 
suffering from the same conflicts in attempt to take f!A, originally 
created on top of B, and apply it on top of A - the thing is that 
Alexei actually pointed to B being the problematic one, failing to 
rebase on top of already (successfully) autosquashed A' (where A' = A 
+ f!A, fixup applied through --autosquash), while it doesn`t fail 
rebasing --onto f!A when f!A is being committed on top of A directly 
(and not through --autosquash).

In that (very?) specific case, proposed `git commit --onto-parent`[1] 
doesn`t suffer from this, as once f!A is successfully applied onto A 
(either squashed in with --amend, or on top of it), we take original 
f!A _snapshot_ (not patch!) made on top of B, and just "declare" it 
B` (being equal to B + f!A, which we already know, and being 
correct), without a need to (try to) apply B patch on top of fixed-up 
A to create B', as `rebase` does (and fails).

> I don't think there is any way for 'git rebase --autosquash' to
> avoid the conflicts unless it used a special fixup merge strategy
> that somehow took advantage of the DAG to resolve the conflicts by
> realizing they come from a later commit. However I don't think that
> could be implemented reliably as sometimes one wants those
> conflicting lines from the later commit to be moved to the earlier
> commit with the fixup.

I think I agree on this part being tricky (if possible at all), but I 
also think this is not what Alexei was complaining about, nor what we 
were discussing (as I tried to explain above) - but please do correct 
me if I misunderstood you.

That said, and what I mentioned already, we might really benefit from 
simple test case(s), showing "rebase --autosquash" failing where 
"rebase --onto" works, as Alexei explained, giving some more (and 
firm) context to the discussion.

I *think* I`ve experienced this in the past myself, but now I can`t 
seem to wrap my head around a reproducible example just yet... :$

Regards, Buga


  reply	other threads:[~2017-12-10  1:20 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-26 22:35 [SCRIPT/RFC 0/3] git-commit --onto-parent (three-way merge, no working tree file changes) Igor Djordjevic
2017-11-26 22:36 ` [SCRIPT/RFC 1/3] Igor Djordjevic
2017-11-26 22:36 ` [SCRIPT/RFC 2/3] git-merge-one-file--cached Igor Djordjevic
2017-11-26 22:45 ` [SCRIPT/RFC 3/3] Igor Djordjevic
2017-11-27 21:54 ` [SCRIPT/RFC 0/3] git-commit --onto-parent (three-way merge, no working tree file changes) Johannes Sixt
2017-11-28  1:15   ` Igor Djordjevic
2017-11-29 19:11     ` Johannes Sixt
2017-11-29 23:10       ` Igor Djordjevic
2017-12-01 17:23         ` Johannes Sixt
2017-12-04  2:33           ` Igor Djordjevic
2017-12-06 18:34             ` Johannes Sixt
2017-12-06 18:40               ` Junio C Hamano
2017-12-08  0:15                 ` Igor Djordjevic
2017-12-08 16:24                   ` Junio C Hamano
2017-12-08 23:54                     ` Igor Djordjevic
2017-12-09  2:18                       ` Alexei Lozovsky
2017-12-09  3:03                         ` Igor Djordjevic
2017-12-09 19:00                           ` [SCRIPT/RFC 0/3] git-commit --onto-parent (three-way merge,noworking " Phillip Wood
2017-12-09 19:01                           ` [SCRIPT/RFC 0/3] git-commit --onto-parent (three-way merge, noworking " Phillip Wood
2017-12-10  1:20                             ` Igor Djordjevic [this message]
2017-12-10 12:22                               ` [SCRIPT/RFC 0/3] git-commit --onto-parent (three-way merge,noworking " Phillip Wood
2017-12-10 23:17                                 ` Igor Djordjevic
2017-12-11  1:13                                   ` Alexei Lozovsky
2017-12-11  1:00                                 ` Alexei Lozovsky
2017-11-30 22:40 ` [SCRIPT/RFC 0/3] git-commit --onto-parent (three-way merge, no working " Chris Nerwert
2017-12-03 23:01   ` Igor Djordjevic

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:

  List information:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

* 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

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).