Git Mailing List Archive mirror
 help / color / mirror / Atom feed
From: Jacob Keller <jacob.e.keller@intel.com>
To: Patrick Steinhardt <ps@pks.im>, <git@vger.kernel.org>
Cc: Jonathan Tan <jonathantanmy@google.com>
Subject: Re: [PATCH 3/8] fetch: fix missing from-reference when fetching HEAD:foo
Date: Wed, 26 Apr 2023 12:20:15 -0700	[thread overview]
Message-ID: <8e08ac5f-b1cb-554c-dc21-4cbd93c348e8@intel.com> (raw)
In-Reply-To: <596e12f03a296d753ee6fe8face9522edc9e397e.1681906948.git.ps@pks.im>



On 4/19/2023 5:31 AM, Patrick Steinhardt wrote:
> When displaying reference updates, we print a line that looks similar to
> the following:
> 
> ```
>  * branch               master          -> master
> ```
> 
> The "branch" bit changes depending on what kind of reference we're
> updating, while both of the right-hand references are computed by
> stripping well-known prefixes like "refs/heads/" or "refs/tags".
> 
> The logic is kind of intertwined though and not easy to follow: we
> precompute both the kind (e.g. "branch") and the what, which is the
> abbreviated remote reference name, in `store_updated_refs()` and then
> pass it down the call chain to `display_ref_update()`.
> 
> There is a set of different cases here:
> 
>     - When the remote reference name is "HEAD" we assume no kind and
>       will thus instead print "[new ref]". We keep what at the empty
>       string.
> 
>     - When the remote reference name has a well-known prefix then the
>       kind would be "branch", "tag" or "remote-tracking branch". The
>       what is the reference with the well-known prefix stripped and in
>       fact matches the output that `prettify_refname()` would return.
> 
>     - Otherwise, we'll again assume no kind and keep the what set to the
>       fully qualified reference name.
> 
> Now there is a bug with the first case here, where the remote reference
> name is "HEAD". As noted, "what" will be set to the empty string. And
> that seems to be intentional because we also use this information to
> update the FETCH_HEAD, and in case we're updating HEAD we seemingly
> don't want to append that to our FETCH_HEAD value.
> 
> But as mentioned, we also use this value to display reference updates.
> And while the call to `display_ref_update()` correctly figures out that
> we meant "HEAD" when `what` is empty, the call to `update_local_ref()`
> doesn't. `update_local_ref()` will then call `display_ref_update()` with
> the empty string and cause the following broken output:
> 
> ```
> $ git fetch --dry-run origin HEAD:foo
> From https://github.com/git/git
>  * [new ref]                          -> foo
> ```
> 
> The HEAD string is clearly missing from the left-hand side of the arrow,
> which is further stressed by the point that the following commands work
> as expected:
> 
> ```
> $ git fetch --dry-run origin HEAD
> From https://github.com/git/git
>  * branch                  HEAD       -> FETCH_HEAD
> 
> $ git fetch --dry-run origin master
> From https://github.com/git/git
>  * branch                  master     -> FETCH_HEAD
>  * branch                  master     -> origin/master
> ```
> 
> Fix this bug by instead unconditionally passing the full reference name
> to `display_ref_update()` which learns to call `prettify_refname()` on
> it. This does fix the above bug and is otherwise functionally the same
> as `prettify_refname()` would only ever strip the well-known prefixes
> just as intended. So at the same time, this also simplifies the code a
> bit.
> 
> Note that this patch also changes formatting of the block that computes
> the "kind" and "what" variables. This is done on purpose so that it is
> part of the diff, hopefully making the change easier to comprehend.
> 
> Signed-off-by: Patrick Steinhardt <ps@pks.im>

The commit message here has a lot of context, but I found it a bit hard
to parse through, especially relative to the actual fix in code.

One suggestion was to load the paragraphs a bit more with the actual
problem being solved first, before beginning a lot of the context.

We also discussed the block of format changes and felt a bit mixed on
whether to include it or not. It does match the coding style guidelines,
but there is no actual functional change made to those lines in this series.

I think its a good improvement, and it does force some extra context
into the diff which makes reading the resulting change easier.

  reply	other threads:[~2023-04-26 19:20 UTC|newest]

Thread overview: 120+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-19 12:31 [PATCH 0/8] fetch: introduce machine-parseable output Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 1/8] fetch: split out tests for output format Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 2/8] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 3/8] fetch: fix missing from-reference when fetching HEAD:foo Patrick Steinhardt
2023-04-26 19:20   ` Jacob Keller [this message]
2023-04-27 10:58     ` Patrick Steinhardt
2023-04-26 19:21   ` Jacob Keller
2023-04-27 10:58     ` Patrick Steinhardt
2023-04-26 19:25   ` Glen Choo
2023-04-27 10:58     ` Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 4/8] fetch: introduce `display_format` enum Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 5/8] fetch: move display format parsing into main function Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 6/8] fetch: move option related variables " Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 7/8] fetch: introduce new `--output-format` option Patrick Steinhardt
2023-04-26 19:40   ` Glen Choo
2023-04-27 10:58     ` Patrick Steinhardt
2023-04-19 12:31 ` [PATCH 8/8] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-04-26 19:52   ` Glen Choo
2023-04-27 10:58     ` Patrick Steinhardt
2023-04-27 23:20       ` Glen Choo
2023-04-28  8:51         ` Patrick Steinhardt
2023-04-28 17:20           ` Glen Choo
2023-05-02 20:55       ` Felipe Contreras
2023-04-24 20:17 ` [PATCH 0/8] fetch: introduce machine-parseable output Felipe Contreras
2023-04-25  9:58   ` Patrick Steinhardt
2023-04-26 19:14     ` Jacob Keller
2023-04-26 20:23       ` Junio C Hamano
2023-04-26 20:30         ` Jacob Keller
2023-04-27 10:58         ` Patrick Steinhardt
2023-04-27 19:46           ` Jacob Keller
2023-04-27 22:49         ` Glen Choo
2023-04-26 20:24       ` Junio C Hamano
2023-04-26 18:54 ` Glen Choo
2023-04-26 21:14   ` Glen Choo
2023-04-26 19:17 ` Jacob Keller
2023-04-27 11:13 ` [PATCH v2 " Patrick Steinhardt
2023-04-27 11:13   ` [PATCH v2 1/8] fetch: split out tests for output format Patrick Steinhardt
2023-04-29 17:34     ` SZEDER Gábor
2023-05-03 11:21       ` Patrick Steinhardt
2023-04-27 11:13   ` [PATCH v2 2/8] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-04-27 11:13   ` [PATCH v2 3/8] fetch: fix missing from-reference when fetching HEAD:foo Patrick Steinhardt
2023-04-27 17:26     ` Glen Choo
2023-04-27 19:49     ` Jacob Keller
2023-04-27 11:13   ` [PATCH v2 4/8] fetch: introduce `display_format` enum Patrick Steinhardt
2023-04-27 11:13   ` [PATCH v2 5/8] fetch: move display format parsing into main function Patrick Steinhardt
2023-04-27 11:13   ` [PATCH v2 6/8] fetch: move option related variables " Patrick Steinhardt
2023-04-27 21:52     ` Junio C Hamano
2023-04-27 11:13   ` [PATCH v2 7/8] fetch: introduce new `--output-format` option Patrick Steinhardt
2023-04-27 22:01     ` Junio C Hamano
2023-04-28 22:03       ` Glen Choo
2023-05-03  9:12         ` Patrick Steinhardt
2023-04-28 22:31     ` Glen Choo
2023-05-03  9:43       ` Patrick Steinhardt
2023-05-03 11:36         ` Patrick Steinhardt
2023-04-27 11:13   ` [PATCH v2 8/8] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-04-27 19:52     ` Jacob Keller
2023-04-28 22:42     ` Glen Choo
2023-05-03 11:34 ` [PATCH v3 0/8] fetch: introduce machine-parseable output Patrick Steinhardt
2023-05-03 11:34   ` [PATCH v3 1/8] fetch: fix `--no-recurse-submodules` with multi-remote fetches Patrick Steinhardt
2023-05-08 22:51     ` Glen Choo
2023-05-09 12:41       ` Patrick Steinhardt
2023-05-03 11:34   ` [PATCH v3 2/8] fetch: split out tests for output format Patrick Steinhardt
2023-05-03 11:34   ` [PATCH v3 3/8] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-05-03 11:34   ` [PATCH v3 4/8] fetch: fix missing from-reference when fetching HEAD:foo Patrick Steinhardt
2023-05-03 11:34   ` [PATCH v3 5/8] fetch: introduce `display_format` enum Patrick Steinhardt
2023-05-03 11:34   ` [PATCH v3 6/8] fetch: move display format parsing into main function Patrick Steinhardt
2023-05-03 11:34   ` [PATCH v3 7/8] fetch: move option related variables " Patrick Steinhardt
2023-05-03 11:34   ` [PATCH v3 8/8] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-05-08 23:42     ` Glen Choo
2023-05-09 12:41       ` Patrick Steinhardt
2023-05-09  0:03     ` Glen Choo
2023-05-03 16:48   ` [PATCH v3 0/8] fetch: introduce machine-parseable output Junio C Hamano
2023-05-03 16:53     ` Junio C Hamano
2023-05-04  7:57       ` Patrick Steinhardt
2023-05-09  0:06   ` Glen Choo
2023-05-09 12:42     ` Patrick Steinhardt
2023-05-09 13:01 ` [PATCH v4 " Patrick Steinhardt
2023-05-09 13:02   ` [PATCH v4 1/8] fetch: fix `--no-recurse-submodules` with multi-remote fetches Patrick Steinhardt
2023-05-09 17:49     ` Junio C Hamano
2023-05-09 18:27       ` Glen Choo
2023-05-10 12:34         ` Patrick Steinhardt
2023-05-09 13:02   ` [PATCH v4 2/8] fetch: split out tests for output format Patrick Steinhardt
2023-05-09 13:02   ` [PATCH v4 3/8] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-05-09 17:58     ` Junio C Hamano
2023-05-10 12:34       ` Patrick Steinhardt
2023-05-09 13:02   ` [PATCH v4 4/8] fetch: fix missing from-reference when fetching HEAD:foo Patrick Steinhardt
2023-05-09 19:28     ` Junio C Hamano
2023-05-10 12:34       ` Patrick Steinhardt
2023-05-09 13:02   ` [PATCH v4 5/8] fetch: introduce `display_format` enum Patrick Steinhardt
2023-05-09 20:19     ` Junio C Hamano
2023-05-10 12:35       ` Patrick Steinhardt
2023-05-09 13:02   ` [PATCH v4 6/8] fetch: move display format parsing into main function Patrick Steinhardt
2023-05-09 20:35     ` Junio C Hamano
2023-05-09 22:30     ` Glen Choo
2023-05-10 12:35       ` Patrick Steinhardt
2023-05-09 13:02   ` [PATCH v4 7/8] fetch: move option related variables " Patrick Steinhardt
2023-05-09 13:02   ` [PATCH v4 8/8] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-05-09 20:43     ` Junio C Hamano
2023-05-10 12:35       ` Patrick Steinhardt
2023-05-10 12:33 ` [PATCH v5 0/9] fetch: introduce machine-parseable output Patrick Steinhardt
2023-05-10 12:34   ` [PATCH v5 1/9] fetch: fix `--no-recurse-submodules` with multi-remote fetches Patrick Steinhardt
2023-05-10 12:34   ` [PATCH v5 2/9] fetch: split out tests for output format Patrick Steinhardt
2023-05-10 12:34   ` [PATCH v5 3/9] fetch: add a test to exercise invalid output formats Patrick Steinhardt
2023-05-10 12:34   ` [PATCH v5 4/9] fetch: print left-hand side when fetching HEAD:foo Patrick Steinhardt
2023-05-12  0:16     ` Glen Choo
2023-05-13 16:59     ` Jeff King
2023-05-15  5:15       ` Patrick Steinhardt
2023-05-10 12:34   ` [PATCH v5 5/9] fetch: refactor calculation of the display table width Patrick Steinhardt
2023-05-12  0:49     ` Glen Choo
2023-05-10 12:34   ` [PATCH v5 6/9] fetch: introduce `display_format` enum Patrick Steinhardt
2023-05-10 12:34   ` [PATCH v5 7/9] fetch: lift up parsing of "fetch.output" config variable Patrick Steinhardt
2023-05-10 12:34   ` [PATCH v5 8/9] fetch: move option related variables into main function Patrick Steinhardt
2023-05-10 12:34   ` [PATCH v5 9/9] fetch: introduce machine-parseable "porcelain" output format Patrick Steinhardt
2023-05-12  1:02     ` Glen Choo
2023-05-10 18:05   ` [PATCH v5 0/9] fetch: introduce machine-parseable output Junio C Hamano
2023-05-11 11:05     ` Patrick Steinhardt
2023-05-11 16:53       ` Junio C Hamano
2023-05-11 17:24       ` Felipe Contreras
2023-05-12  1:09   ` Glen Choo
2023-05-12  7:16     ` Patrick Steinhardt

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

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=8e08ac5f-b1cb-554c-dc21-4cbd93c348e8@intel.com \
    --to=jacob.e.keller@intel.com \
    --cc=git@vger.kernel.org \
    --cc=jonathantanmy@google.com \
    --cc=ps@pks.im \
    /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.
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).