sync: only use --cruft when git supports it.

git gc --cruft was added in 2.37.0.

Bug: https://crbug.com/gerrit/16270
Change-Id: I71e46741e33472a92f16d6f11c51a23e1e55d869
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/346577
Reviewed-by: Emily Shaffer <emilyshaffer@google.com>
Tested-by: LaMont Jones <lamontjones@google.com>
Reviewed-by: Mike Frysinger <vapier@google.com>

docs/manifest-format.md

@@ -105,6 +105,8 @@ following DTD:
   <!ATTLIST extend-project groups CDATA #IMPLIED>
   <!ATTLIST extend-project revision CDATA #IMPLIED>
   <!ATTLIST extend-project remote CDATA #IMPLIED>
+  <!ATTLIST extend-project dest-branch CDATA #IMPLIED>
+  <!ATTLIST extend-project upstream CDATA #IMPLIED>
 
   <!ELEMENT remove-project EMPTY>
   <!ATTLIST remove-project name  CDATA #REQUIRED>
@@ -423,6 +425,12 @@ project.  Same syntax as the corresponding element of `project`.
 Attribute `remote`: If specified, overrides the remote of the original
 project.  Same syntax as the corresponding element of `project`.
 
+Attribute `dest-branch`: If specified, overrides the dest-branch of the original
+project.  Same syntax as the corresponding element of `project`.
+
+Attribute `upstream`: If specified, overrides the upstream of the original
+project.  Same syntax as the corresponding element of `project`.
+
 ### Element annotation
 
 Zero or more annotation elements may be specified as children of a

manifest_xml.py

@@ -1289,6 +1289,8 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
           remote = self._default.remote
         else:
           remote = self._get_remote(node)
+        dest_branch = node.getAttribute('dest-branch')
+        upstream = node.getAttribute('upstream')
 
         named_projects = self._projects[name]
         if dest_path and not path and len(named_projects) > 1:
@@ -1304,6 +1306,10 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
 
           if remote_name:
             p.remote = remote.ToRemoteSpec(name)
+          if dest_branch:
+            p.dest_branch = dest_branch
+          if upstream:
+            p.upstream = upstream
 
           if dest_path:
             del self._paths[p.relpath]
@@ -1940,11 +1946,14 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
     fromKeys = sorted(fromProjects.keys())
     toKeys = sorted(toProjects.keys())
 
-    diff = {'added': [], 'removed': [], 'changed': [], 'unreachable': []}
+    diff = {'added': [], 'removed': [], 'missing': [], 'changed': [], 'unreachable': []}
 
     for proj in fromKeys:
       if proj not in toKeys:
         diff['removed'].append(fromProjects[proj])
+      elif not fromProjects[proj].Exists:
+        diff['missing'].append(toProjects[proj])
+        toKeys.remove(proj)
       else:
         fromProj = fromProjects[proj]
         toProj = toProjects[proj]

project.py

@@ -26,6 +26,7 @@ import sys
 import tarfile
 import tempfile
 import time
+from typing import NamedTuple
 import urllib.parse
 
 from color import Coloring
@@ -45,6 +46,14 @@ from repo_trace import IsTrace, Trace
 from git_refs import GitRefs, HEAD, R_HEADS, R_TAGS, R_PUB, R_M, R_WORKTREE_M
 
 
+class SyncNetworkHalfResult(NamedTuple):
+  """Sync_NetworkHalf return value."""
+  # True if successful.
+  success: bool
+  # Did we query the remote? False when optimized_fetch is True and we have the
+  # commit already present.
+  remote_fetched: bool
+
 # Maximum sleep time allowed during retries.
 MAXIMUM_RETRY_SLEEP_SEC = 3600.0
 # +-10% random jitter is added to each Fetches retry sleep duration.
@@ -1133,7 +1142,7 @@ class Project(object):
     if archive and not isinstance(self, MetaProject):
       if self.remote.url.startswith(('http://', 'https://')):
         _error("%s: Cannot fetch archives from http/https remotes.", self.name)
-        return False
+        return SyncNetworkHalfResult(False, False)
 
       name = self.relpath.replace('\\', '/')
       name = name.replace('/', '_')
@@ -1144,19 +1153,19 @@ class Project(object):
         self._FetchArchive(tarpath, cwd=topdir)
       except GitError as e:
         _error('%s', e)
-        return False
+        return SyncNetworkHalfResult(False, False)
 
       # From now on, we only need absolute tarpath
       tarpath = os.path.join(topdir, tarpath)
 
       if not self._ExtractArchive(tarpath, path=topdir):
-        return False
+        return SyncNetworkHalfResult(False, True)
       try:
         platform_utils.remove(tarpath)
       except OSError as e:
         _warn("Cannot remove archive %s: %s", tarpath, str(e))
       self._CopyAndLinkFiles()
-      return True
+      return SyncNetworkHalfResult(True, True)
 
     # If the shared object dir already exists, don't try to rebootstrap with a
     # clone bundle download.  We should have the majority of objects already.
@@ -1220,9 +1229,11 @@ class Project(object):
       depth = self.manifest.manifestProject.depth
 
     # See if we can skip the network fetch entirely.
+    remote_fetched = False
     if not (optimized_fetch and
             (ID_RE.match(self.revisionExpr) and
              self._CheckForImmutableRevision())):
+      remote_fetched = True
       if not self._RemoteFetch(
               initial=is_new,
               quiet=quiet, verbose=verbose, output_redir=output_redir,
@@ -1231,7 +1242,7 @@ class Project(object):
               submodules=submodules, force_sync=force_sync,
               ssh_proxy=ssh_proxy,
               clone_filter=clone_filter, retry_fetches=retry_fetches):
-        return False
+        return SyncNetworkHalfResult(False, remote_fetched)
 
     mp = self.manifest.manifestProject
     dissociate = mp.dissociate
@@ -1244,7 +1255,7 @@ class Project(object):
         if p.stdout and output_redir:
           output_redir.write(p.stdout)
         if p.Wait() != 0:
-          return False
+          return SyncNetworkHalfResult(False, remote_fetched)
         platform_utils.remove(alternates_file)
 
     if self.worktree:
@@ -1253,7 +1264,7 @@ class Project(object):
       self._InitMirrorHead()
       platform_utils.remove(os.path.join(self.gitdir, 'FETCH_HEAD'),
                             missing_ok=True)
-    return True
+    return SyncNetworkHalfResult(True, remote_fetched)
 
   def PostRepoUpgrade(self):
     self._InitHooks()
@@ -1451,6 +1462,8 @@ class Project(object):
         cnt_mine += 1
 
     if not upstream_gain and cnt_mine == len(local_changes):
+      # The copy/linkfile config may have changed.
+      self._CopyAndLinkFiles()
       return
 
     if self.IsDirty(consider_untracked=False):
@@ -2794,35 +2807,6 @@ class Project(object):
         else:
           raise
 
-  def _InitialCheckoutStart(self):
-    """Called when checking out a project for the first time.
-
-    This will use temporary non-visible paths so we can be safely interrupted
-    without leaving incomplete state behind.
-    """
-    paths = [f'{x}.tmp' for x in (self.relpath, self.worktree, self.gitdir, self.objdir)]
-    for p in paths:
-      platform_utils.rmtree(p, ignore_errors=True)
-    self.UpdatePaths(*paths)
-
-  def _InitialCheckoutFinalizeNetworkHalf(self):
-    """Finalize the object dirs after network syncing works."""
-    # Once the network half finishes, we can move the objects into the right
-    # place by removing the ".tmp" suffix on the dirs.
-    platform_utils.rmtree(self.gitdir[:-4], ignore_errors=True)
-    os.rename(self.gitdir, self.gitdir[:-4])
-    self.UpdatePaths(self.relpath, self.worktree, self.gitdir[:-4], self.objdir[:-4])
-
-  def _InitialCheckoutFinalizeLocalHalf(self):
-    """Finalize the initial checkout and make it available."""
-    assert self.gitdir == self.objdir
-    # Once the local half finishes, we can move the manifest dir into the right
-    # place by removing the ".tmp" suffix on the dirs.
-    platform_utils.rmtree(self.worktree[:-4], ignore_errors=True)
-    os.rename(self.worktree, self.worktree[:-4])
-    self.UpdatePaths(
-        self.relpath[:-4], self.worktree[:-4], self.gitdir, self.objdir)
-
   def _InitGitWorktree(self):
     """Init the project using git worktrees."""
     self.bare_git.worktree('prune')
@@ -3709,8 +3693,6 @@ class ManifestProject(MetaProject):
               (GitConfig.ForUser().UrlInsteadOf(manifest_url),),
               file=sys.stderr)
 
-      self._InitialCheckoutStart()
-
       # The manifest project object doesn't keep track of the path on the
       # server where this git is located, so let's save that here.
       mirrored_manifest_git = None
@@ -3867,17 +3849,19 @@ class ManifestProject(MetaProject):
           is_new=is_new, quiet=not verbose, verbose=verbose,
           clone_bundle=clone_bundle, current_branch_only=current_branch_only,
           tags=tags, submodules=submodules, clone_filter=clone_filter,
-          partial_clone_exclude=self.manifest.PartialCloneExclude):
+          partial_clone_exclude=self.manifest.PartialCloneExclude).success:
         r = self.GetRemote()
         print('fatal: cannot obtain manifest %s' % r.url, file=sys.stderr)
+
+        # Better delete the manifest git dir if we created it; otherwise next
+        # time (when user fixes problems) we won't go through the "is_new" logic.
+        if is_new:
+          platform_utils.rmtree(self.gitdir)
         return False
 
       if manifest_branch:
         self.MetaBranchSwitch(submodules=submodules)
 
-      if is_new:
-        self._InitialCheckoutFinalizeNetworkHalf()
-
       syncbuf = SyncBuffer(self.config)
       self.Sync_LocalHalf(syncbuf, submodules=submodules)
       syncbuf.Finish()
@@ -3900,9 +3884,6 @@ class ManifestProject(MetaProject):
       with open(dest, 'wb') as f:
         f.write(manifest_data)
 
-    if is_new:
-      self._InitialCheckoutFinalizeLocalHalf()
-
     try:
       self.manifest.Link(manifest_name)
     except ManifestParseError as e:

release/update-manpages

@@ -59,18 +59,26 @@ def main(argv):
   version = RepoSourceVersion()
   cmdlist = [['help2man', '-N', '-n', f'repo {cmd} - manual page for repo {cmd}',
     '-S', f'repo {cmd}', '-m', 'Repo Manual', f'--version-string={version}',
-    '-o', MANDIR.joinpath(f'repo-{cmd}.1.tmp'), TOPDIR.joinpath('repo'),
+    '-o', MANDIR.joinpath(f'repo-{cmd}.1.tmp'), './repo',
     '-h', f'help {cmd}'] for cmd in subcmds.all_commands]
   cmdlist.append(['help2man', '-N', '-n', 'repository management tool built on top of git',
     '-S', 'repo', '-m', 'Repo Manual', f'--version-string={version}',
-    '-o', MANDIR.joinpath('repo.1.tmp'), TOPDIR.joinpath('repo'),
+    '-o', MANDIR.joinpath('repo.1.tmp'), './repo',
     '-h', '--help-all'])
 
   with tempfile.TemporaryDirectory() as tempdir:
-    repo_dir = Path(tempdir) / '.repo'
+    tempdir = Path(tempdir)
+    repo_dir = tempdir / '.repo'
     repo_dir.mkdir()
     (repo_dir / 'repo').symlink_to(TOPDIR)
 
+    # Create a repo wrapper using the active Python executable.  We can't pass
+    # this directly to help2man as it's too simple, so insert it via shebang.
+    data = (TOPDIR / 'repo').read_text(encoding='utf-8')
+    tempbin = tempdir / 'repo'
+    tempbin.write_text(f'#!{sys.executable}\n' + data, encoding='utf-8')
+    tempbin.chmod(0o755)
+
     # Run all cmd in parallel, and wait for them to finish.
     with multiprocessing.Pool() as pool:
       pool.map(partial(worker, cwd=tempdir, check=True), cmdlist)

subcmds/diffmanifests.py

@@ -118,6 +118,16 @@ synced and their revisions won't be found.
         self.printRevision(project.revisionExpr)
         self.out.nl()
 
+    if diff['missing']:
+      self.out.nl()
+      self.printText('missing projects : \n')
+      self.out.nl()
+      for project in diff['missing']:
+        self.printProject('\t%s' % (project.relpath))
+        self.printText(' at revision ')
+        self.printRevision(project.revisionExpr)
+        self.out.nl()
+
     if diff['changed']:
       self.out.nl()
       self.printText('changed projects : \n')

subcmds/selfupdate.py

@@ -51,7 +51,7 @@ need to be performed by an end-user.
       _PostRepoUpgrade(self.manifest)
 
     else:
-      if not rp.Sync_NetworkHalf():
+      if not rp.Sync_NetworkHalf().success:
         print("error: can't update repo", file=sys.stderr)
         sys.exit(1)
 

subcmds/sync.py

@@ -21,10 +21,12 @@ import multiprocessing
 import netrc
 from optparse import SUPPRESS_HELP
 import os
+import shutil
 import socket
 import sys
 import tempfile
 import time
+from typing import NamedTuple
 import urllib.error
 import urllib.parse
 import urllib.request
@@ -58,11 +60,68 @@ from error import RepoChangedException, GitError, ManifestParseError
 import platform_utils
 from project import SyncBuffer
 from progress import Progress
+from repo_trace import IsTrace, Trace
 import ssh
 from wrapper import Wrapper
 from manifest_xml import GitcManifest
 
 _ONE_DAY_S = 24 * 60 * 60
+# Env var to implicitly turn off object backups.
+REPO_BACKUP_OBJECTS = 'REPO_BACKUP_OBJECTS'
+
+_BACKUP_OBJECTS = os.environ.get(REPO_BACKUP_OBJECTS) != '0'
+
+
+class _FetchOneResult(NamedTuple):
+  """_FetchOne return value.
+
+  Attributes:
+    success (bool): True if successful.
+    project (Project): The fetched project.
+    start (float): The starting time.time().
+    finish (float): The ending time.time().
+    remote_fetched (bool): True if the remote was actually queried.
+  """
+  success: bool
+  project: Project
+  start: float
+  finish: float
+  remote_fetched: bool
+
+
+class _FetchResult(NamedTuple):
+  """_Fetch return value.
+
+  Attributes:
+    success (bool): True if successful.
+    projects (set[str]): The names of the git directories of fetched projects.
+  """
+  success: bool
+  projects: set[str]
+
+
+class _FetchMainResult(NamedTuple):
+  """_FetchMain return value.
+
+  Attributes:
+    all_projects (list[Project]): The fetched projects.
+  """
+  all_projects: list[Project]
+
+
+class _CheckoutOneResult(NamedTuple):
+  """_CheckoutOne return value.
+
+  Attributes:
+    success (bool): True if successful.
+    project (Project): The project.
+    start (float): The starting time.time().
+    finish (float): The ending time.time().
+  """
+  success: bool
+  project: Project
+  start: float
+  finish: float
 
 
 class Sync(Command, MirrorSafeCommand):
@@ -406,7 +465,7 @@ later is required to fix a server side protocol bug.
     success = False
     buf = io.StringIO()
     try:
-      success = project.Sync_NetworkHalf(
+      sync_result = project.Sync_NetworkHalf(
           quiet=opt.quiet,
           verbose=opt.verbose,
           output_redir=buf,
@@ -420,6 +479,7 @@ later is required to fix a server side protocol bug.
           ssh_proxy=self.ssh_proxy,
           clone_filter=project.manifest.CloneFilter,
           partial_clone_exclude=project.manifest.PartialCloneExclude)
+      success = sync_result.success
 
       output = buf.getvalue()
       if (opt.verbose or not success) and output:
@@ -437,7 +497,8 @@ later is required to fix a server side protocol bug.
       raise
 
     finish = time.time()
-    return (success, project, start, finish)
+    return _FetchOneResult(success, project, start, finish,
+                           sync_result.remote_fetched)
 
   @classmethod
   def _FetchInitChild(cls, ssh_proxy):
@@ -448,6 +509,7 @@ later is required to fix a server side protocol bug.
 
     jobs = opt.jobs_network
     fetched = set()
+    remote_fetched = set()
     pm = Progress('Fetching', len(projects), delay=False, quiet=opt.quiet)
 
     objdir_project_map = dict()
@@ -458,10 +520,16 @@ later is required to fix a server side protocol bug.
     def _ProcessResults(results_sets):
       ret = True
       for results in results_sets:
-        for (success, project, start, finish) in results:
+        for result in results:
+          success = result.success
+          project = result.project
+          start = result.start
+          finish = result.finish
           self._fetch_times.Set(project, finish - start)
           self.event_log.AddSync(project, event_log.TASK_SYNC_NETWORK,
                                  start, finish, success)
+          if result.remote_fetched:
+            remote_fetched.add(project)
           # Check for any errors before running any more tasks.
           # ...we'll let existing jobs finish, though.
           if not success:
@@ -519,7 +587,7 @@ later is required to fix a server side protocol bug.
     if not self.outer_client.manifest.IsArchive:
       self._GCProjects(projects, opt, err_event)
 
-    return (ret, fetched)
+    return _FetchResult(ret, fetched)
 
   def _FetchMain(self, opt, args, all_projects, err_event,
                  ssh_proxy, manifest):
@@ -545,7 +613,9 @@ later is required to fix a server side protocol bug.
     to_fetch.extend(all_projects)
     to_fetch.sort(key=self._fetch_times.Get, reverse=True)
 
-    success, fetched = self._Fetch(to_fetch, opt, err_event, ssh_proxy)
+    result = self._Fetch(to_fetch, opt, err_event, ssh_proxy)
+    success = result.success
+    fetched = result.projects
     if not success:
       err_event.set()
 
@@ -555,7 +625,7 @@ later is required to fix a server side protocol bug.
       if err_event.is_set():
         print('\nerror: Exited sync due to fetch errors.\n', file=sys.stderr)
         sys.exit(1)
-      return
+      return _FetchMainResult([])
 
     # Iteratively fetch missing and/or nested unregistered submodules
     previously_missing_set = set()
@@ -578,12 +648,14 @@ later is required to fix a server side protocol bug.
       if previously_missing_set == missing_set:
         break
       previously_missing_set = missing_set
-      success, new_fetched = self._Fetch(missing, opt, err_event, ssh_proxy)
+      result = self._Fetch(missing, opt, err_event, ssh_proxy)
+      success = result.success
+      new_fetched = result.projects
       if not success:
         err_event.set()
       fetched.update(new_fetched)
 
-    return all_projects
+    return _FetchMainResult(all_projects)
 
   def _CheckoutOne(self, detach_head, force_sync, project):
     """Checkout work tree for one project
@@ -615,7 +687,7 @@ later is required to fix a server side protocol bug.
     if not success:
       print('error: Cannot checkout %s' % (project.name), file=sys.stderr)
     finish = time.time()
-    return (success, project, start, finish)
+    return _CheckoutOneResult(success, project, start, finish)
 
   def _Checkout(self, all_projects, opt, err_results):
     """Checkout projects listed in all_projects
@@ -630,7 +702,11 @@ later is required to fix a server side protocol bug.
 
     def _ProcessResults(pool, pm, results):
       ret = True
-      for (success, project, start, finish) in results:
+      for result in results:
+        success = result.success
+        project = result.project
+        start = result.start
+        finish = result.finish
         self.event_log.AddSync(project, event_log.TASK_SYNC_LOCAL,
                                start, finish, success)
         # Check for any errors before running any more tasks.
@@ -652,6 +728,36 @@ later is required to fix a server side protocol bug.
         callback=_ProcessResults,
         output=Progress('Checking out', len(all_projects), quiet=opt.quiet)) and not err_results
 
+  def _backup_cruft(self, bare_git):
+    """Save a copy of any cruft from `git gc`."""
+    # Find any cruft packs in the current gitdir, and save them.
+    # b/221065125 (repo sync complains that objects are missing).  This does
+    # not prevent that state, but makes it so that the missing objects are
+    # available.
+    objdir = bare_git._project.objdir
+    pack_dir = os.path.join(objdir, 'pack')
+    bak_dir = os.path.join(objdir, '.repo', 'pack.bak')
+    if not _BACKUP_OBJECTS or not platform_utils.isdir(pack_dir):
+      return
+    saved = []
+    files = set(platform_utils.listdir(pack_dir))
+    to_backup = []
+    for f in files:
+      base, ext = os.path.splitext(f)
+      if base + '.mtimes' in files:
+        to_backup.append(f)
+    if to_backup:
+      os.makedirs(bak_dir, exist_ok=True)
+    for fname in to_backup:
+      bak_fname = os.path.join(bak_dir, fname)
+      if not os.path.exists(bak_fname):
+        saved.append(fname)
+        # Use a tmp file so that we are sure of a complete copy.
+        shutil.copy(os.path.join(pack_dir, fname), bak_fname + '.tmp')
+        shutil.move(bak_fname + '.tmp', bak_fname)
+    if saved:
+      Trace('%s saved %s', bare_git._project.name, ' '.join(saved))
+
   def _GCProjects(self, projects, opt, err_event):
     pm = Progress('Garbage collecting', len(projects), delay=False, quiet=opt.quiet)
     pm.update(inc=0, msg='prescan')
@@ -694,13 +800,22 @@ later is required to fix a server side protocol bug.
 
     jobs = opt.jobs
 
+    gc_args = ['--auto']
+    backup_cruft = False
+    if git_require((2, 37, 0)):
+      gc_args.append('--cruft')
+      backup_cruft = True
+    pack_refs_args = ()
     if jobs < 2:
       for (run_gc, bare_git) in tidy_dirs.values():
         pm.update(msg=bare_git._project.name)
+
         if run_gc:
-          bare_git.gc('--auto')
+          bare_git.gc(*gc_args)
         else:
-          bare_git.pack_refs()
+          bare_git.pack_refs(*pack_refs_args)
+        if backup_cruft:
+          self._backup_cruft(bare_git)
       pm.end()
       return
 
@@ -715,15 +830,17 @@ later is required to fix a server side protocol bug.
       try:
         try:
           if run_gc:
-            bare_git.gc('--auto', config=config)
+            bare_git.gc(*gc_args, config=config)
           else:
-            bare_git.pack_refs(config=config)
+            bare_git.pack_refs(*pack_refs_args, config=config)
         except GitError:
           err_event.set()
         except Exception:
           err_event.set()
           raise
       finally:
+        if backup_cruft:
+          self._backup_cruft(bare_git)
         pm.finish(bare_git._project.name)
         sem.release()
 
@@ -1071,14 +1188,13 @@ later is required to fix a server side protocol bug.
               file=sys.stderr)
 
     for m in self.ManifestList(opt):
-      mp = m.manifestProject
-      is_standalone_manifest = bool(mp.standalone_manifest_url)
-      if not is_standalone_manifest:
-        mp.PreSync()
+      if not m.manifestProject.standalone_manifest_url:
+        m.manifestProject.PreSync()
 
-      if opt.repo_upgraded:
-        _PostRepoUpgrade(m, quiet=opt.quiet)
+    if opt.repo_upgraded:
+      _PostRepoUpgrade(manifest, quiet=opt.quiet)
 
+    mp = manifest.manifestProject
     if opt.mp_update:
       self._UpdateAllManifestProjects(opt, mp, manifest_name)
     else:
@@ -1168,8 +1284,9 @@ later is required to fix a server side protocol bug.
         with ssh.ProxyManager(manager) as ssh_proxy:
           # Initialize the socket dir once in the parent.
           ssh_proxy.sock()
-          all_projects = self._FetchMain(opt, args, all_projects, err_event,
-                                         ssh_proxy, manifest)
+          result = self._FetchMain(opt, args, all_projects, err_event,
+                                   ssh_proxy, manifest)
+          all_projects = result.all_projects
 
       if opt.network_only:
         return

tests/test_manifest_xml.py

@@ -874,3 +874,27 @@ class ExtendProjectElementTests(ManifestParseTestCase):
     else:
       self.assertEqual(manifest.projects[0].relpath, 'bar')
       self.assertEqual(manifest.projects[1].relpath, 'y')
+
+  def test_extend_project_dest_branch(self):
+    manifest = self.getXmlManifest("""
+<manifest>
+  <remote name="default-remote" fetch="http://localhost" />
+  <default remote="default-remote" revision="refs/heads/main" dest-branch="foo" />
+  <project name="myproject" />
+  <extend-project name="myproject" dest-branch="bar" />
+</manifest>
+""")
+    self.assertEqual(len(manifest.projects), 1)
+    self.assertEqual(manifest.projects[0].dest_branch, 'bar')
+
+  def test_extend_project_upstream(self):
+    manifest = self.getXmlManifest("""
+<manifest>
+  <remote name="default-remote" fetch="http://localhost" />
+  <default remote="default-remote" revision="refs/heads/main" />
+  <project name="myproject" />
+  <extend-project name="myproject" upstream="bar" />
+</manifest>
+""")
+    self.assertEqual(len(manifest.projects), 1)
+    self.assertEqual(manifest.projects[0].upstream, 'bar')