From: Junio C Hamano <gitster@pobox•com>
To: Eric Sunshine <sunshine@sunshineco•com>
Cc: Git List <git@vger•kernel.org>,
Martin von Zweigbergk <martinvonz@gmail•com>,
John Keeping <john@keeping•me.uk>,
Jonathan Nieder <jrnieder@gmail•com>
Subject: Re: [PATCH 2/2] merge-base: "--reflog" mode finds fork point from reflog entries
Date: Thu, 24 Oct 2013 15:13:24 -0700 [thread overview]
Message-ID: <xmqqwql2l3ln.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <CAPig+cQ2tWFXX-RYnUrHEZCaqaPV6ZwgoPfiNPv9P1jFNTGEYg@mail.gmail.com> (Eric Sunshine's message of "Thu, 24 Oct 2013 17:43:16 -0400")
Eric Sunshine <sunshine@sunshineco•com> writes:
> On Thu, Oct 24, 2013 at 5:26 PM, Junio C Hamano <gitster@pobox•com> wrote:
>> Eric Sunshine <sunshine@sunshineco•com> writes:
>>
>>> On Thu, Oct 24, 2013 at 3:11 PM, Junio C Hamano <gitster@pobox•com> wrote:
>>>> diff --git a/t/t6010-merge-base.sh b/t/t6010-merge-base.sh
>>>> index f80bba8..3a1abee 100755
>>>> --- a/t/t6010-merge-base.sh
>>>> +++ b/t/t6010-merge-base.sh
>>>> @@ -230,4 +230,31 @@ test_expect_success 'criss-cross merge-base for octopus-step' '
>>>> test_cmp expected.sorted actual.sorted
>>>> '
>>>>
>>>> +test_expect_success 'using reflog to find the fork point' '
>>>> + git reset --hard &&
>>>> + git checkout -b base $E &&
>>>> + (
>>>> + for count in 1 2 3 4 5
>>>> + do
>>>> + git commit --allow-empty -m "Base commit #$count" &&
>>>> + git rev-parse HEAD >expect$count &&
>>>> + git checkout -B derived &&
>>>> + git commit --allow-empty -m "Derived #$count" &&
>>>> + git rev-parse HEAD >derived$count &&
>>>> + git checkout base &&
>>>> + count=$(( $count + 1 )) || exit 1
>>>> + done
>>>
>>> Did you want && here?
>>
>> No, I did not. Can't you tell from the fact that I didn't put one
>> there ;-)?
>>
>> It does not hurt to have one there, but it is not necessary.
>>
>> Because the loop itself does not &&-cascade from anything else, the
>> only case anything after "done &&" would be skipped and making the
>> whole thing fail would be when anything inside the loop fails, but
>> we already "exit 1" to terminate the whole subprocess in that case,
>> so we will not continue past the loop.
>
> I didn't read inside the loop closely enough to see that. Sorry
> for the noise.
Heh, you helped me realize that the above was suboptimal, and it
wasn't a noise ;-)
We could do it this way without the subshell and the exit, I would
think.
test_expect_success 'using reflog to find the fork point' '
git reset --hard &&
git checkout -b base $E &&
for count in 1 2 3 4 5
do
git commit --allow-empty -m "Base commit #$count" &&
git rev-parse HEAD >expect$count &&
git checkout -B derived &&
git commit --allow-empty -m "Derived #$count" &&
git rev-parse HEAD >derived$count &&
git checkout base &&
count=$(( $count + 1 )) || break
done &&
for count in 1 2 3 4 5
do
git merge-base --reflog base $(cat derived$count) >actual &&
test_cmp expect$count actual || break
done &&
# check defaulting to HEAD
git merge-base --reflog base >actual &&
test_cmp expect5 actual
'
To the earlier code, somebody could add
(
+ more setup code &&
+ yet more setup code &&
for count in 1 2 3 4 5
inside the subshell and we would fail to notice fairlure from the
new setup code if we didn't have && after the first "done". There
is much less risk of that kind of breakage if we did the loop
without subshell and exit and instead with the usual &&-cascade.
Thanks.
next prev parent reply other threads:[~2013-10-24 22:13 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-16 18:53 [PATCH] rebase: use reflog to find common base with upstream John Keeping
2013-10-16 19:24 ` Jonathan Nieder
2013-10-16 19:44 ` John Keeping
2013-10-21 5:03 ` Martin von Zweigbergk
2013-10-21 11:24 ` John Keeping
2013-10-22 6:24 ` Martin von Zweigbergk
2013-10-24 19:04 ` Junio C Hamano
2013-10-24 19:11 ` [PATCH 0/2] finding the fork point from reflog entries Junio C Hamano
2013-10-24 19:11 ` [PATCH 1/2] merge-base: use OPT_CMDMODE and clarify the command line parsing Junio C Hamano
2013-10-24 19:11 ` [PATCH 2/2] merge-base: "--reflog" mode finds fork point from reflog entries Junio C Hamano
2013-10-24 21:01 ` Eric Sunshine
2013-10-24 21:26 ` Junio C Hamano
2013-10-24 21:43 ` Eric Sunshine
2013-10-24 22:13 ` Junio C Hamano [this message]
2013-10-24 22:21 ` [PATCH v2 " Junio C Hamano
2013-10-25 7:12 ` Johannes Sixt
2013-10-25 8:09 ` John Keeping
2013-10-25 8:17 ` Johannes Sixt
2013-10-25 16:53 ` Junio C Hamano
2013-10-25 21:38 ` [PATCH v3 2/2] merge-base: teach "--fork-point" mode Junio C Hamano
2013-10-25 21:56 ` Eric Sunshine
2013-10-26 5:15 ` Martin von Zweigbergk
2013-10-28 14:47 ` Junio C Hamano
2013-10-26 9:00 ` John Keeping
2013-10-28 19:13 ` Junio C Hamano
2013-10-29 8:51 ` John Keeping
2013-10-29 20:11 ` Junio C Hamano
2013-10-24 20:54 ` [PATCH 0/2] finding the fork point from reflog entries John Keeping
2013-10-24 21:20 ` Junio C Hamano
2013-10-24 21:31 ` John Keeping
2013-10-24 21:40 ` John Keeping
2013-10-24 21:50 ` John Keeping
2013-10-25 2:46 ` Junio C Hamano
2013-10-22 5:40 ` [PATCH] rebase: use reflog to find common base with upstream Martin von Zweigbergk
2013-10-24 20:26 ` John Keeping
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