builtin/clone: allow remote helpers to detect repo #641
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
In 18c9cb7 (builtin/clone: create the refdb with the correct object format, 2023-12-12), we have changed git-clone(1) so that it delays creation of the refdb until after it has learned about the remote's object format. This change was required for the reftable backend, which encodes the object format into the tables. So if we pre-initialized the refdb with the default object format, but the remote uses a different object format than that, then the resulting tables would have encoded the wrong object format. This change unfortunately breaks remote helpers which try to access the repository that is about to be created. Because the refdb has not yet been initialized at the point where we spawn the remote helper, we also don't yet have "HEAD" or "refs/". Consequently, any Git commands ran by the remote helper which try to access the repository would fail because it cannot be discovered. This is essentially a chicken-and-egg problem: we cannot initialize the refdb because we don't know about the object format. But we cannot learn about the object format because the remote helper may be unable to access the partially-initialized repository. Ideally, we would address this issue via capabilities. But the remote helper protocol is not structured in a way that guarantees that the capability announcement happens before the remote helper tries to access the repository. Instead, fix this issue by partially initializing the refdb up to the point where it becomes discoverable by Git commands. Reported-by: Mike Hommey <mh@glandium.org> Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Oliver Schneider <oschneider@exocad.com>
derrickstolee
approved these changes
Apr 15, 2024
jeffhostetler
approved these changes
Apr 15, 2024
dscho
deleted the
msft-git-backport/ps/remote-helper-repo-initialization-fix
branch
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is a backport of git-for-windows#4908 to address git-for-windows#4843 where cloning no longer worked if the user has configured any
includeIf.*.onbranchsettings in their gitconfig.