Add `repo.reprojectcmd`, the checkout counterpart to `repo.fetchcmd`.
When set, `repo sync` runs this command instead of Git to materialize a
project's index and worktree at the target tree, while `repo` handles
ref updates directly via `git update-ref`.
This replaces Git's tree materialization steps: detaching HEAD,
fast-forwarding, and hard-resetting. Rebasing is not delegated, and the
command is skipped if HEAD is already at the target, if HEAD is ahead of
the target during fast-forward, or for MetaProjects.
The command runs in a subshell with project environment variables (such
as `REPO_TREV`). Before running, `repo` ensures no operation is in
progress and no staged changes exist. Worktree collision detection is
delegated to the command (preserving benign unstaged/untracked edits).
Afterward, `repo` verifies that HEAD was untouched and that the index
matches the target tree.
Like `repo.fetchcmd`, this requires `repo.uselocalgitdirs`. Nested
projects and submodules are unsupported; `repo sync` fails if the
manifest contains any while `repo.reprojectcmd` is enabled.
Verified end-to-end with repo init using local-gitdirs, repo.fetchcmd,
and repo.reprojectcmd ('git -C $REPO_PATH read-tree -m -u $REPO_TREV'):
* Verified detached HEAD checkout and correct reflog generation across
projects.
* Verified benign unstaged edits and untracked files survive checkout.
* Verified conflicting untracked files fail with exit 128 without
clobbering worktree.
* Verified staged changes fail upfront before reprojectcmd is executed.
Bug: 513329573
Change-Id: I964d24d22dccffc05a9b991ad69f3a7e93268c01
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/626281
Tested-by: Gavin Mak <gavinmak@google.com>
Reviewed-by: Brian Gan <brgan@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>
Introduce support for `repo.fetchcmd` configuration, allowing users to
specify a custom command to fetch project data instead of
`_RemoteFetch`.
When `repo.fetchcmd` is specified, `repo` will execute it instead of
`_RemoteFetch` during the network half of sync. Note that
`repo.fetchcmd` requires `repo.uselocalgitdirs` to be enabled.
The command is executed in a subshell with project-context environment
variables, including the new `REPO_TREV` (target revision resolved to a
commit hash) and `REPO_PROJECT_FETCH_URL`.
After execution, `repo` verifies that the target commit is available and
that the tracking ref and FETCH_HEAD are correctly updated.
Tested with:
```
> ~/git-repo/repo init -u https://android-review.googlesource.com/platform/manifest \
--repo-url file:///usr/local/google/home/gavinmak/git-repo \
--groups developers \
--no-repo-verify \
--use-local-gitdirs
...
> git config --file .repo/manifests.git/config repo.fetchcmd 'mkdir -p $REPO_PATH && cd $REPO_PATH && if [ ! -d .git ]; then git init && git remote add aosp $REPO_PROJECT_FETCH_URL; fi && git fetch aosp $REPO_TREV && git reset --hard $REPO_TREV && mkdir -p .git/refs/remotes/aosp && echo $REPO_TREV > .git/refs/remotes/aosp/main && echo $REPO_TREV > .git/FETCH_HEAD'
> ~/git-repo/repo sync -j32
warning: repo is not tracking a remote branch, so it will not receive updates; run `repo init --repo-rev=stable` to fix.
You are currently enrolled in Git submodules experiment (go/android-submodules-quickstart). Use --no-use-superproject to override.
Syncing: 100% (4/4), done in 1m15.686s
Finalizing sync state...
repo sync has finished successfully.
```
Bug: 513329573
Change-Id: I754d3f3c78e86fdeee1a72115297a75b571bc497
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/583883
Reviewed-by: Becky Siegel <beckysiegel@google.com>
Tested-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>
Gavin Mak