project: fix m/ pseudo ref handling with git worktrees
Since most ref namespaces are shared among all worktrees, trying to
set the pseudo m/<branch> in the common git repo ends up clobbering
each other when using shared checkouts. For example, in CrOS:
<project path="src/third_party/kernel/v3.8"
name="chromiumos/third_party/kernel"
revision="refs/heads/chromeos-3.8" />
<project path="src/third_party/kernel/v3.10"
name="chromiumos/third_party/kernel"
revision="refs/heads/chromeos-3.10" />
Trying to set m/master in chromiumos/third_party/kernel.git/ will
keep clobbering the other.
Instead, when using git worktrees, lets set the m/ pseudo ref to
point into the refs/worktree/ namespace which is unique to each
git worktree. So we have in the common dir:
chromiumos/third_party/kernel.git/:
refs/remotes/m/master:
ref: refs/worktree/m/master
And then in each worktree we point refs/worktree/m/master to the
respective manifest revision expression. Now people can use the
m/master in each git worktree and have it resolve to the right
commit for that worktree.
Bug: https://crbug.com/gerrit/12404
Change-Id: I78814bdd5dd67bb13218c4c6ccd64f8a15dd0a52
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/256952
Tested-by: Mike Frysinger <vapier@google.com>
Reviewed-by: David Pursehouse <dpursehouse@collab.net>
diff --git a/git_refs.py b/git_refs.py
index 02b98cb..e2b62ab 100644
--- a/git_refs.py
+++ b/git_refs.py
@@ -23,6 +23,8 @@
R_HEADS = 'refs/heads/'
R_TAGS = 'refs/tags/'
R_PUB = 'refs/published/'
+R_WORKTREE = 'refs/worktree/'
+R_WORKTREE_M = R_WORKTREE + 'm/'
R_M = 'refs/remotes/m/'
diff --git a/project.py b/project.py
index b93dcd5..fe55371 100644
--- a/project.py
+++ b/project.py
@@ -42,7 +42,7 @@
import progress
from repo_trace import IsTrace, Trace
-from git_refs import GitRefs, HEAD, R_HEADS, R_TAGS, R_PUB, R_M
+from git_refs import GitRefs, HEAD, R_HEADS, R_TAGS, R_PUB, R_M, R_WORKTREE_M
from pyversion import is_python3
if is_python3():
@@ -2741,10 +2741,19 @@
os.makedirs(self.objdir)
self.bare_objdir.init()
- # Enable per-worktree config file support if possible. This is more a
- # nice-to-have feature for users rather than a hard requirement.
- if self.use_git_worktrees and git_require((2, 19, 0)):
- self.EnableRepositoryExtension('worktreeConfig')
+ if self.use_git_worktrees:
+ # Set up the m/ space to point to the worktree-specific ref space.
+ # We'll update the worktree-specific ref space on each checkout.
+ if self.manifest.branch:
+ self.bare_git.symbolic_ref(
+ '-m', 'redirecting to worktree scope',
+ R_M + self.manifest.branch,
+ R_WORKTREE_M + self.manifest.branch)
+
+ # Enable per-worktree config file support if possible. This is more a
+ # nice-to-have feature for users rather than a hard requirement.
+ if git_require((2, 19, 0)):
+ self.EnableRepositoryExtension('worktreeConfig')
# If we have a separate directory to hold refs, initialize it as well.
if self.objdir != self.gitdir:
@@ -2879,25 +2888,37 @@
def _InitMRef(self):
if self.manifest.branch:
- self._InitAnyMRef(R_M + self.manifest.branch)
+ if self.use_git_worktrees:
+ # We can't update this ref with git worktrees until it exists.
+ # We'll wait until the initial checkout to set it.
+ if not os.path.exists(self.worktree):
+ return
+
+ base = R_WORKTREE_M
+ active_git = self.work_git
+ else:
+ base = R_M
+ active_git = self.bare_git
+
+ self._InitAnyMRef(base + self.manifest.branch, active_git)
def _InitMirrorHead(self):
- self._InitAnyMRef(HEAD)
+ self._InitAnyMRef(HEAD, self.bare_git)
- def _InitAnyMRef(self, ref):
+ def _InitAnyMRef(self, ref, active_git):
cur = self.bare_ref.symref(ref)
if self.revisionId:
if cur != '' or self.bare_ref.get(ref) != self.revisionId:
msg = 'manifest set to %s' % self.revisionId
dst = self.revisionId + '^0'
- self.bare_git.UpdateRef(ref, dst, message=msg, detach=True)
+ active_git.UpdateRef(ref, dst, message=msg, detach=True)
else:
remote = self.GetRemote(self.remote.name)
dst = remote.ToLocal(self.revisionExpr)
if cur != dst:
msg = 'manifest set to %s' % self.revisionExpr
- self.bare_git.symbolic_ref('-m', msg, ref, dst)
+ active_git.symbolic_ref('-m', msg, ref, dst)
def _CheckDirReference(self, srcdir, destdir, share_refs):
# Git worktrees don't use symlinks to share at all.
@@ -3028,6 +3049,8 @@
with open(os.path.join(git_worktree_path, 'gitdir'), 'w') as fp:
print(os.path.relpath(dotgit, git_worktree_path), file=fp)
+ self._InitMRef()
+
def _InitWorkTree(self, force_sync=False, submodules=False):
realdotgit = os.path.join(self.worktree, '.git')
tmpdotgit = realdotgit + '.tmp'
