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refs: support local GIT_NAMESPACE views - #2378

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johnrichardrinehart:local-namespace-views
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refs: support local GIT_NAMESPACE views#2378
johnrichardrinehart wants to merge 2 commits into
git:masterfrom
johnrichardrinehart:local-namespace-views

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@johnrichardrinehart

@johnrichardrinehart johnrichardrinehart commented Aug 9, 2026

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Git namespaces currently isolate refs for git-upload-pack and
git-receive-pack, but ordinary local Git commands do not use
GIT_NAMESPACE as a repository view.

This prevents a shared object database from providing normal local branch
semantics. For example, GIT_NAMESPACE=bar git rev-parse refs/heads/main
cannot resolve refs/namespaces/bar/refs/heads/main.

This series makes ordinary ref access namespace-aware when GIT_NAMESPACE
is set. Local commands resolve and update logical refs inside the selected
namespace, while upload-pack, receive-pack, and HTTP backend retain their
existing server behavior.

The series also makes garbage collection protect refs in every namespace.
This preserves objects shared by namespaces without requiring per-namespace
object stores or a separate garbage-collection command.

The series contains two commits:

  • refs: support local namespace views
  • gc: protect refs in every namespace

The tests cover local branch and ref operations, fetch, push, worktrees,
existing server namespace behavior, hidden-ref queries, and cross-namespace
garbage collection.

Checks run:

  • t1500-rev-parse.sh
  • t3200-branch.sh
  • t5509-fetch-push-namespaces.sh
  • t5510-fetch.sh
  • t6021-rev-list-exclude-hidden.sh

This work was implemented by GPT-5.6 Luna High.

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Welcome to GitGitGadget

Hi @johnrichardrinehart, and welcome to GitGitGadget, the GitHub App to send patch series to the Git mailing list from GitHub Pull Requests.

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There are issues in commit e5e6541:
refs: support local namespace views

  • Commit checks stopped - the message is too short
  • Commit not signed off

@gitgitgadget-git

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There are issues in commit a2514a9:
gc: protect refs in every namespace

  • Commit checks stopped - the message is too short
  • Commit not signed off

@gitgitgadget-git

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There is an issue in commit f6ec17a:
refs: support local namespace views

  • Lines in the body of the commit messages should be wrapped between 60 and 76 characters.
    Indented lines, and lines without whitespace, are exempt

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Error: User johnrichardrinehart is not yet permitted to use GitGitGadget

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Error: User johnrichardrinehart is not yet permitted to use GitGitGadget

@gitgitgadget-git

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Error: User johnrichardrinehart is not yet permitted to use GitGitGadget

Git namespaces isolate refs for server commands, but local Git commands do
not use GIT_NAMESPACE as a repository view in shared object databases.

Map logical refs to the selected namespace for local ref reads, writes,
iteration, reflogs, and transactions. Keep upload-pack, receive-pack, and
HTTP backend behavior unchanged by disabling the local view in server code.
Keep hidden-ref queries independent of the local namespace view.

Add tests for local ref operations and preserve server namespace behavior.

Signed-off-by: John Rinehart <johnrichardrinehart@gmail.com>
A shared object database can contain objects reachable only from a namespace
outside the active view, so garbage collection must retain those objects.

Make maintenance enumerate namespaces while ordinary commands keep using the
active namespace. Protect namespace refs when packing reachable objects and
test that namespaced git gc --prune=now preserves an outside ref.

Signed-off-by: John Rinehart <johnrichardrinehart@gmail.com>
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