Re: [PATCH v15 09/10] fetch: set remote/HEAD if it does not exist

From: Josh Steadmon <steadmon@google.com>
Date: Dec 5, 2024, 19:50 UTC
Message-ID: <444kgiknevb3kwtypjjc2glryaav27t5fafgyzqq5257w7o4pf@4fngcyfmvfcp>
In-Reply-To: <wmu5ld4xsfjz2tpp54jmxqroma423t5nn2jh3q5gq2wswr6fkm@vrlhigyuxfzu>

On 2024.12.05 10:58, Josh Steadmon wrote:

Show 36 quoted lines

> On 2024.11.22 13:28, Bence Ferdinandy wrote:
> > When cloning a repository remote/HEAD is created, but when the user
> > creates a repository with git init, and later adds a remote, remote/HEAD
> > is only created if the user explicitly runs a variant of "remote
> > set-head". Attempt to set remote/HEAD during fetch, if the user does not
> > have it already set. Silently ignore any errors.
> > 
> > Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
> 
> At $DAYJOB, we noticed that this breaks `git fetch --tags`, although I
> haven't had a chance to figure out what causes the error just yet.
> 
> I was able to bisect down to this commit using Jonathan Tan's
> reproduction script:
> 
> rm -rf test_tag_1 test_tag_2
> GIT=~/git/bin-wrappers/git
> mkdir test_tag_1 && cd test_tag_1
> REMOTE=$(pwd)
> $GIT init .
> touch foo.txt
> $GIT add foo.txt
> $GIT commit foo.txt -m "commit one"
> $GIT tag foo
> cd ..
> mkdir test_tag_2 && cd test_tag_2
> $GIT init .
> echo fetch --tags
> $GIT fetch --tags "file://$REMOTE"
> echo regular fetch
> $GIT fetch "file://$REMOTE" 'refs/tags/*:refs/tags/*'
> $GIT --version
> 
> 
> Prior to this change, the first `$GIT fetch --tags "file://$REMOTE"`
> fetches the `foo` tag; with this change, it does not.

FWIW, moving this:

@@ -1643,6 +1703,8 @@ static int do_fetch(struct transport *transport,
                                    "refs/tags/");
        }

+       strvec_push(&transport_ls_refs_options.ref_prefixes, "HEAD");
+

to just above the prior `if` block fixes our issue and doesn't break any
tests. However, I'm not sure yet why the order of ref_prefixes should
matter here.