From: Junio C Hamano <gitster@pobox.com>
To: Siddharth Kannan <kannan.siddharth12@gmail.com>
Cc: git@vger.kernel.org, Matthieu.Moy@imag.fr,
pranit.bauva@gmail.com, peff@peff.net, pclouds@gmail.com,
sandals@crustytoothpaste.ath.cx
Subject: Re: [PATCH 5/6 v5] merge.c: delegate handling of "-" shorthand to revision.c:get_sha1
Date: Wed, 01 Mar 2017 15:05:52 -0800 [thread overview]
Message-ID: <xmqqinnsegxb.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <xmqqpoi0eho8.fsf@gitster.mtv.corp.google.com> (Junio C. Hamano's message of "Wed, 01 Mar 2017 14:49:43 -0800")
Junio C Hamano <gitster@pobox.com> writes:
> Siddharth Kannan <kannan.siddharth12@gmail.com> writes:
>
>> The callchain for handling each argument contains the function
>> revision.c:get_sha1 where the shorthand for "-" ~ "@{-1}" has already been
>> implemented in a previous patch; the complete callchain leading to that
>> function is:
>>
>> 1. merge.c:collect_parents
>> 2. commit.c:get_merge_parent : this function calls revision.c:get_sha1
>>
>> This patch also adds a test for checking that the shorthand works properly
>
> This breaks "git merge".
>
>> +test_expect_success 'merge - should work' '
>> + git checkout testing-2 &&
>> + git merge - &&
>> + git rev-parse HEAD HEAD^^ | sort >actual &&
>> + git rev-parse master testing-1 | sort >expect &&
>> + test_cmp expect actual
>
> This test is not sufficient to catch a regression I seem to be
> seeing.
>
> $ git checkout side
> $ git checkout pu
> $ git merge -
>
> used to say "Merge branch 'side' into pu". With this series merged,
> I seem to be getting "Merge commit '-' into pu".
You stopped at get_sha1_1() in your 3817cebabc ("sha1_name.c: teach
get_sha1_1 "-" shorthand for "@{-1}"", 2017-02-25), instead of going
down to get_sha1_basic() and teaching it that "-" means the same
thing as "@{-1}", which would in turn require you to teach
dwim_ref() that "-" is the same thing as "@{-1}". As dwim_ref()
does not know about "-" and does not expand it to the refname like
it expands "@{-1}", it would break and that is why 3817cebabc punts
at a bit higher in the callchain.
The breakage by this patch to "git merge" happens for the same
reason. cmd_merge() calls collect_parents() which annotates the
commits that are merged with their textual name, which used to be
"@{-1}" without this patch but now "-" is passed as-is. This
annotation will be given to merge_name(), and the first thing it
does is dwim_ref(). The function knows what to do with "@{-1}",
but it does not know what to do with "-", and that is why you end up
producing "Merge commit '-' into ...".
Dropping this patch from the series would make things consistent
with what was done in 3817cebabc and I think that is a sensible
place to stop. After the dust settles, We _can_ later dig further
by teaching dwim_ref() and friends what "-" means, and when it is
done, this patch would become useful.
Thanks.
next prev parent reply other threads:[~2017-03-01 23:07 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-25 7:24 [PATCH 0/6 v5] allow "-" as a shorthand for "previous branch" Siddharth Kannan
2017-02-25 7:24 ` [PATCH 1/6 v5] revision.c: do not update argv with unknown option Siddharth Kannan
2017-02-25 7:24 ` [PATCH 2/6 v5] revision.c: swap if/else blocks Siddharth Kannan
2017-02-25 7:24 ` [PATCH 3/6 v5] revision.c: args starting with "-" might be a revision Siddharth Kannan
2017-02-25 7:24 ` [PATCH 4/6 v5] sha1_name.c: teach get_sha1_1 "-" shorthand for "@{-1}" Siddharth Kannan
2017-03-14 2:10 ` [PATCH 6/6 v5] sha1_name.c: avoid parsing @{-1} unnecessarily mash
2017-02-25 7:24 ` [PATCH 5/6 v5] merge.c: delegate handling of "-" shorthand to revision.c:get_sha1 Siddharth Kannan
2017-03-01 22:49 ` Junio C Hamano
2017-03-01 23:05 ` Junio C Hamano [this message]
2017-02-25 7:24 ` [PATCH 6/6 v5] revert.c: delegate handling of "-" shorthand to setup_revisions Siddharth Kannan
2017-03-01 23:18 ` Junio C Hamano
2017-02-25 7:32 ` [PATCH 1/6 v5] revision.c: do not update argv with unknown option Siddharth Kannan
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=xmqqinnsegxb.fsf@gitster.mtv.corp.google.com \
--to=gitster@pobox.com \
--cc=Matthieu.Moy@imag.fr \
--cc=git@vger.kernel.org \
--cc=kannan.siddharth12@gmail.com \
--cc=pclouds@gmail.com \
--cc=peff@peff.net \
--cc=pranit.bauva@gmail.com \
--cc=sandals@crustytoothpaste.ath.cx \
/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).