From: Junio C Hamano <gitster@pobox.com>
To: Jonathan Tan <jonathantanmy@google.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH v5 1/3] ls-refs: report unborn targets of symrefs
Date: Fri, 29 Jan 2021 14:04:18 -0800 [thread overview]
Message-ID: <xmqqtuqzs8m5.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <20210129202306.723272-1-jonathantanmy@google.com> (Jonathan Tan's message of "Fri, 29 Jan 2021 12:23:06 -0800")
Jonathan Tan <jonathantanmy@google.com> writes:
>> I think the use of &&-cascade is iffy here. Even when we are *not*
>> accepting request for unborn, we should still parse it as such.
>> This does not matter in today's code, but it is a basic courtesy for
>> future developers who may add more "else if" after it.
>>
>> IOW
>>
>> else if (!strcmp("unborn", arg)) {
>> if (!data.allow_unborn)
>> ; /* we are not accepting the request */
>> else
>> data.unborn = 1;
>> }
>>
>> I wrote the above in longhand only for documentation purposes; in
>> practice,
>>
>> else if (!strcmp("unborn", arg))
>> data.unborn = data.allow_unborn;
>>
>> may suffice.
>
> My thinking was (and is) that falling through in the case of a
> disallowed argument (as opposed to a completely unrecognized argument)
> makes it more straightforward later if we ever decide to tighten
> validation of the ls-refs request - we would only have to put some code
> at the end that reports back to the user.
Sorry, I do not quite follow. If "unborn" is conditionally allowed,
you can extend what I suggested above like so:
if (we see we got an unborn request) {
- if (allowed)
+ if (partially allowed)
+ record that we got unborn request and will
+ partially respond to it
+ else if (allowed)
record that we got unborn request;
+ else
+ report that we don't accept unborn request;
}
This will matter even more if you write more else-if. The
downstream of else-if clauses are forced to interpret (and fail)
"unborn" request they are not interested in.
>> > if (request->status != PACKET_READ_FLUSH)
>> > die(_("expected flush after ls-refs arguments"));
>> >
>> > - head_ref_namespaced(send_ref, &data);
>> > + send_possibly_unborn_head(&data);
>> > for_each_namespaced_ref(send_ref, &data);
>>
>> And here is another caller of send_ref(). Are we sure that
>> send_ref()'s expectation is satisfied by this caller when the
>> iteration encounters a broken ref (e.g. refs/heads/broken not a
>> symref but names an object that does not exist and get_sha1()
>> yielding 0{40}), or a dangling symref (e.g. refs/remotes/origin/HEAD
>> pointing at something that does not exist)?
>
> I assume that by "this caller" you mean for_each_namespaced_ref(), since
> you mention an iteration. I believe so - send_ref has been changed to
> tolerate a NULL (as in (void*)0, not 0{40}) oid, and that is the only
> change, so if it worked previously, it should still work now.
So a dangling symref, e.g. "refs/remotes/origin/HEAD -> trunk" when
no "refs/remotes/origin/trunk" exists, is not reported to send_ref()
in the same way as an unborn "HEAD"? I would have expected that we'd
report where it points at, and for that to work, you'd have to use
not just the vanilla send_ref() as the callback, but something that
knows how to do "are we expected to send unborn symrefs" logic, like
send_possibly_unborn_head does.
That "changed to tolerate ... should work" worries me.
If "for_each_namespaced_ref(send_ref, &data)" will never call send_ref()
with NULL (as in (void *)0) oid, then that would be OK, but if it
ends up calling with NULL somehow, it is responsible to ensure that
data->symrefs is true and flag has REF_ISSYMREF set, or send_ref()
would misbehave, (see the first part of your message, which I am
responding to), no?
next prev parent reply other threads:[~2021-01-29 22:05 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-08 1:31 Cloning empty repository uses locally configured default branch name Jonathan Tan
2020-12-08 2:16 ` Junio C Hamano
2020-12-08 2:32 ` brian m. carlson
2020-12-08 18:55 ` Jonathan Tan
2020-12-08 21:00 ` Junio C Hamano
2020-12-08 15:58 ` Jeff King
2020-12-08 20:06 ` Jonathan Tan
2020-12-08 21:15 ` Jeff King
2020-12-11 21:05 ` [PATCH] clone: in protocol v2, use remote's default branch Jonathan Tan
2020-12-11 23:41 ` Junio C Hamano
2020-12-14 12:38 ` Ævar Arnfjörð Bjarmason
2020-12-14 15:51 ` Felipe Contreras
2020-12-14 16:30 ` Junio C Hamano
2020-12-15 1:41 ` Ævar Arnfjörð Bjarmason
2020-12-15 2:22 ` Junio C Hamano
2020-12-15 2:38 ` Jeff King
2020-12-15 2:55 ` Junio C Hamano
2020-12-15 4:36 ` Jeff King
2020-12-16 3:09 ` Junio C Hamano
2020-12-16 18:39 ` Jeff King
2020-12-16 20:56 ` Junio C Hamano
2020-12-18 6:19 ` Jeff King
2020-12-15 3:22 ` Felipe Contreras
2020-12-14 19:25 ` Jonathan Tan
2020-12-14 19:42 ` Felipe Contreras
2020-12-15 1:27 ` Jeff King
2020-12-15 19:10 ` Jonathan Tan
2020-12-16 2:07 ` [PATCH v2 0/3] Cloning with remote unborn HEAD Jonathan Tan
2020-12-16 2:07 ` [PATCH v2 1/3] ls-refs: report unborn targets of symrefs Jonathan Tan
2020-12-16 6:16 ` Junio C Hamano
2020-12-16 23:49 ` Jonathan Tan
2020-12-16 18:23 ` Jeff King
2020-12-16 23:54 ` Jonathan Tan
2020-12-17 1:32 ` Junio C Hamano
2020-12-18 6:16 ` Jeff King
2020-12-16 2:07 ` [PATCH v2 2/3] connect, transport: add no-op arg for future patch Jonathan Tan
2020-12-16 6:20 ` Junio C Hamano
2020-12-16 2:07 ` [PATCH v2 3/3] clone: respect remote unborn HEAD Jonathan Tan
2020-12-21 22:30 ` [PATCH v3 0/3] Cloning with " Jonathan Tan
2020-12-21 22:30 ` [PATCH v3 1/3] ls-refs: report unborn targets of symrefs Jonathan Tan
2020-12-21 22:31 ` [PATCH v3 2/3] connect, transport: add no-op arg for future patch Jonathan Tan
2020-12-21 22:31 ` [PATCH v3 3/3] clone: respect remote unborn HEAD Jonathan Tan
2020-12-21 23:48 ` [PATCH v3 0/3] Cloning with " Junio C Hamano
2021-01-21 20:14 ` Jeff King
2020-12-22 21:54 ` [PATCH v4 " Jonathan Tan
2020-12-22 21:54 ` [PATCH v4 1/3] ls-refs: report unborn targets of symrefs Jonathan Tan
2021-01-21 20:48 ` Jeff King
2021-01-26 18:13 ` Jonathan Tan
2021-01-26 23:16 ` Jeff King
2020-12-22 21:54 ` [PATCH v4 2/3] connect, transport: add no-op arg for future patch Jonathan Tan
2021-01-21 20:55 ` Jeff King
2021-01-26 18:16 ` Jonathan Tan
2020-12-22 21:54 ` [PATCH v4 3/3] clone: respect remote unborn HEAD Jonathan Tan
2021-01-21 21:02 ` Jeff King
2021-01-26 18:22 ` Jonathan Tan
2021-01-26 23:04 ` Jeff King
2021-01-28 5:50 ` Junio C Hamano
2020-12-22 22:06 ` [PATCH v4 0/3] Cloning with " Junio C Hamano
2021-01-26 18:55 ` [PATCH v5 " Jonathan Tan
2021-01-26 18:55 ` [PATCH v5 1/3] ls-refs: report unborn targets of symrefs Jonathan Tan
2021-01-26 21:38 ` Junio C Hamano
2021-01-26 23:03 ` Junio C Hamano
2021-01-30 3:55 ` Jonathan Tan
2021-01-26 23:20 ` Jeff King
2021-01-26 23:38 ` Junio C Hamano
2021-01-29 20:23 ` Jonathan Tan
2021-01-29 22:04 ` Junio C Hamano [this message]
2021-02-02 2:20 ` Jonathan Tan
2021-02-02 5:00 ` Junio C Hamano
2021-01-27 1:28 ` Ævar Arnfjörð Bjarmason
2021-01-30 4:04 ` Jonathan Tan
2021-01-26 18:55 ` [PATCH v5 2/3] connect, transport: encapsulate arg in struct Jonathan Tan
2021-01-26 21:54 ` Junio C Hamano
2021-01-30 4:06 ` Jonathan Tan
2021-01-26 18:55 ` [PATCH v5 3/3] clone: respect remote unborn HEAD Jonathan Tan
2021-01-26 22:24 ` Junio C Hamano
2021-01-30 4:27 ` Jonathan Tan
2021-01-27 1:11 ` [PATCH v5 0/3] Cloning with " Junio C Hamano
2021-01-27 4:25 ` Jeff King
2021-01-27 6:14 ` Junio C Hamano
2021-01-27 1:41 ` Ævar Arnfjörð Bjarmason
2021-01-30 4:41 ` Jonathan Tan
2021-01-30 11:13 ` Ævar Arnfjörð Bjarmason
2021-02-02 2:22 ` Jonathan Tan
2021-02-03 14:23 ` Ævar Arnfjörð Bjarmason
2021-02-05 22:28 ` Junio C Hamano
2021-02-02 2:14 ` [PATCH v6 " Jonathan Tan
2021-02-02 2:14 ` [PATCH v6 1/3] ls-refs: report unborn targets of symrefs Jonathan Tan
2021-02-02 16:55 ` Junio C Hamano
2021-02-02 18:34 ` Jonathan Tan
2021-02-02 22:17 ` Junio C Hamano
2021-02-03 1:04 ` Jonathan Tan
2021-02-02 2:15 ` [PATCH v6 2/3] connect, transport: encapsulate arg in struct Jonathan Tan
2021-02-02 2:15 ` [PATCH v6 3/3] clone: respect remote unborn HEAD Jonathan Tan
2021-02-05 4:58 ` [PATCH v7 0/3] Cloning with " Jonathan Tan
2021-02-05 4:58 ` [PATCH v7 1/3] ls-refs: report unborn targets of symrefs Jonathan Tan
2021-02-05 16:10 ` Jeff King
2021-02-05 4:58 ` [PATCH v7 2/3] connect, transport: encapsulate arg in struct Jonathan Tan
2021-02-05 4:58 ` [PATCH v7 3/3] clone: respect remote unborn HEAD Jonathan Tan
2021-02-05 5:25 ` [PATCH v7 0/3] Cloning with " Junio C Hamano
2021-02-05 16:15 ` Jeff King
2021-02-05 21:15 ` Ævar Arnfjörð Bjarmason
2021-02-05 23:07 ` Junio C Hamano
2021-02-05 20:48 ` [PATCH v8 " Jonathan Tan
2021-02-05 20:48 ` [PATCH v8 1/3] ls-refs: report unborn targets of symrefs Jonathan Tan
2021-02-05 20:48 ` [PATCH v8 2/3] connect, transport: encapsulate arg in struct Jonathan Tan
2021-02-05 20:48 ` [PATCH v8 3/3] clone: respect remote unborn HEAD Jonathan Tan
2021-02-06 18:51 ` [PATCH v8 0/3] Cloning with " Junio C Hamano
2021-02-08 22:28 ` Junio C Hamano
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