Re: [PATCH 0/7] Add a new --remerge-diff capability to show & log

On Tue, Aug 31, 2021 at 4:05 AM Bagas Sanjaya [off-list ref] wrote:

On 31/08/21 09.26, Elijah Newren via GitGitGadget wrote:

quoted

Here are some patches to add a --remerge-diff capability to show & log,
which works by comparing merge commits to an automatic remerge (note that
the automatic remerge tree can contain files with conflict markers).

Here are some example commits you can try this out on (with git show
--remerge-diff $COMMIT):

  * git.git conflicted merge: 07601b5b36
  * git.git non-conflicted change: bf04590ecd
  * linux.git conflicted merge: eab3540562fb
  * linux.git non-conflicted change: 223cea6a4f05

<snip>...

quoted

In regards to the performance point above, the timing for running the
following command:

time git log --min-parents=2 --max-parents=2 $DIFF_FLAG | wc -l


in linux.git (with v5.4 checked out, since my copy of linux is very out of
date) is as follows:

DIFF_FLAG=--cc:            71m 31.536s
DIFF_FLAG=--remerge-diff:  31m  3.170s


Note that there are 62476 merges in this history. Also, output size is:

DIFF_FLAG=--cc:            2169111 lines
DIFF_FLAG=--remerge-diff:  2458020 lines

Which repo did you mean by linux.git? Kernel developers often work
against Linus' mainline tree [1], while end-users (including myself)
prefer stable tree (which is mainline + stable release branches and
tags) [2].

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[2]: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

$ git remote -v
origin git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
(fetch)
origin git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
(push)
$ git log -1 origin/master
commit 11a48a5a18c63fd7621bb050228cebf13566e4d8 (tag: v5.6-rc2,
origin/master, origin/HEAD, master)
Author: Linus Torvalds [off-list ref]
Date:   Sun Feb 16 13:16:59 2020 -0800

    Linux 5.6-rc2
$ git log -1 HEAD
commit 219d54332a09e8d8741c1e1982f5eae56099de85 (HEAD, tag: v5.4)
Author: Linus Torvalds [off-list ref]
Date:   Sun Nov 24 16:32:01 2019 -0800

    Linux 5.4