Re: [PATCH] git-rebase--interactive.sh: add config option for custom

[Junio C Hamano <gitster@pobox.com>]

Mike Rappazzo <rappazzo@gmail.com> writes:

> On Mon, Jun 8, 2015 at 11:28 AM, Junio C Hamano <gitster@pobox.com> wrote:
>
>> This is optional, but I still wonder why the command line cannot be
>> more like this, though:
>>
>>         format=$(git config --get rebase.insnFormat)
>>         git log --format="%H ${format-%s}" --reverse --right-only --topo-order \
>>                 $revisions ${restrict_revision+^$restrict_revision} |
>>         while read -r sha1 junk
>>         do
>>                 ...
>>
>> That way we can optimize one "sed" process away.
>>
>> If this is a good idea, it needs to be a separate follow-up patch
>> that changes "%m filtered by sed" to "use --right-only".  I do not
>> think such a change breaks anything, but I do not deal with complex
>> histories myself, so...
>
> As far as I can tell, the rev-list will return multiple lines when not
> using 'oneline'.  The 'sed -n' will join the lines back together.

There is no joining going on.

To "rev-list", a custom --pretty/--format is a signal to trigger its
"verbose" mode, and it shows a "commit <object-name>" line and then
the line in the format specified, e.g.

  $ git rev-list --pretty='%m%H %<(35,trunc)%s' --right-only --reverse ...2024d3
  commit 1e9676ec0a771de06abca3009eb4bdc5a4ae3312
  >1e9676ec0a771de06abca3009eb4bdc5a4ae3312 lockfile: replace random() by ran..
  commit 2024d3176536fd437b4c0a744161e96bc150a24e
  >2024d3176536fd437b4c0a744161e96bc150a24e help.c: wrap wait-only poll() inv..
  ...

Because of that, "format=%m | sed -n s/>//p" would be one way to
make sure that all lines we care about are prefixed by '>' so that
we can pick them while discarding anything else.  So you do need
filtering unless switch to "log", even if you used --right-only.

That is why I didn't use "rev-list" in the message you are
responding to.