From: Carl Baldwin <carl@ecbaldwin.net>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: Git Mailing List <git@vger.kernel.org>
Subject: Re: Bring together merge and rebase
Date: Tue, 26 Dec 2017 12:44:09 -0700 [thread overview]
Message-ID: <20171226194408.GA22855@Carl-MBP.ecbaldwin.net> (raw)
In-Reply-To: <87vagtqszf.fsf@evledraar.gmail.com>
On Tue, Dec 26, 2017 at 06:49:56PM +0100, Ævar Arnfjörð Bjarmason wrote:
> New headers should be added after existing headers, but other than
> that it won't choke on it. See 4b2bced559 when the encoding header was
> added, this also passes most tests:
>
> diff --git a/commit.c b/commit.c
> index cab8d4455b..cd2bafbaa0 100644
> --- a/commit.c
> +++ b/commit.c
> @@ -1565,6 +1565,8 @@ int commit_tree_extended(const char *msg, size_t msg_len,
> if (!encoding_is_utf8)
> strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
>
> + strbuf_addf(&buffer, "replaces 0000000000000000000000000000000000000000\n");
> +
> while (extra) {
> add_extra_header(&buffer, extra);
> extra = extra->next;
>
> Only "most" since of course this changes the sha1 of every commit git
> creates from what you get now.
>
> > Even if core git code does not simply choke on it, I would like push and
> > pull to follow these pointers and transfer the history behind them. I
> > assumed that git would not do this today. I would also like gc to
> > preserve e8aa79baf6 as if it were referenced by a parent pointer so that
> > it doesn't purge it from the history.
>
> It won't pay any attention to them if "replaces" is something entirely
> new, what I was pointing out in my earlier reply is that you can simply
> *also* create the parent pointers to these no-op merge commits that hide
> away the previous history the "replaces" headers will be referencing.
>
> The reason to do that is 100% backwards compatibility, and and only
> needing to make minor UI changes to have this feature (to e.g. history
> walking), as opposed to needing to hack everything that now follows
> "parent" or constructs a commit graph.
Thank you for clarifying this. I have learned something.
> Sure, it could be opt in, be a new format etc. But you haven't
> explained why you think a feature like this would need to rely on an
> entirely new parent structure and side-DAG, as opposed to just the
> more minor changes I'm pointing out above, and which I think will give
> you what you need from a UX level.
I have not wrapped my head around it enough to convince myself that it
gives what I'm after. Let me spend a little more time with it to get a
feel for it.
Carl
next prev parent reply other threads:[~2017-12-26 19:44 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-23 6:10 Bring together merge and rebase Carl Baldwin
2017-12-23 18:59 ` Ævar Arnfjörð Bjarmason
2017-12-23 21:01 ` Carl Baldwin
2017-12-23 22:09 ` Ævar Arnfjörð Bjarmason
2017-12-26 0:16 ` Carl Baldwin
2017-12-26 1:28 ` Jacob Keller
2017-12-26 23:30 ` Igor Djordjevic
2017-12-26 17:49 ` Ævar Arnfjörð Bjarmason
2017-12-26 19:44 ` Carl Baldwin [this message]
2017-12-26 20:19 ` Paul Smith
2017-12-26 21:07 ` Carl Baldwin
2017-12-23 22:19 ` Randall S. Becker
2017-12-25 20:05 ` Carl Baldwin
2017-12-23 23:01 ` Johannes Schindelin
2017-12-24 14:13 ` Alexei Lozovsky
2018-01-04 15:44 ` Johannes Schindelin
2017-12-25 23:43 ` Carl Baldwin
2017-12-26 0:01 ` Randall S. Becker
2018-01-04 19:49 ` Martin Fick
2017-12-23 22:30 ` Johannes Schindelin
2017-12-25 3:52 ` Theodore Ts'o
2017-12-26 1:16 ` Carl Baldwin
2017-12-26 1:47 ` Jacob Keller
2017-12-26 6:02 ` Carl Baldwin
2017-12-26 8:40 ` Jacob Keller
2018-01-04 19:19 ` Martin Fick
2018-01-05 0:31 ` Martin Fick
2018-01-05 5:09 ` Carl Baldwin
2018-01-05 5:20 ` Carl Baldwin
2017-12-26 18:04 ` Theodore Ts'o
2017-12-26 20:31 ` Carl Baldwin
2018-01-04 20:06 ` Martin Fick
2018-01-05 5:06 ` Carl Baldwin
2018-01-04 19:54 ` Martin Fick
2018-01-05 4:08 ` Carl Baldwin
2018-01-05 20:14 ` Junio C Hamano
2018-01-06 17:29 ` Carl Baldwin
2018-01-06 17:32 ` Carl Baldwin
2018-01-06 21:38 ` Theodore Ts'o
2017-12-27 4:35 ` Carl Baldwin
2017-12-27 13:35 ` Alexei Lozovsky
2017-12-28 5:23 ` Carl Baldwin
2017-12-26 4:08 ` Mike Hommey
2017-12-27 2:44 ` Carl Baldwin
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