info: reuse branch snapshots and combine history walks

Derive the current branch from GetBranches so attached HEAD and refs are
resolved once, including overview reporting. Replace the two
complementary rev-list calls in --all output with one --left-right
symmetric-difference walk and partition its records in memory.

Bug: 553599402
Change-Id: I01d5db804cbf591ecc0e08d6605971f0f5a38538
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/634005
Tested-by: Gavin Mak <gavinmak@google.com>
Reviewed-by: Brian Gan <brgan@google.com>
Commit-Queue: Gavin Mak <gavinmak@google.com>

command.py

@@ -17,7 +17,7 @@ import multiprocessing
 import optparse
 import os
 import re
-from typing import TYPE_CHECKING
+from typing import List, Optional, TYPE_CHECKING
 
 from error import InvalidProjectGroupsError
 from error import NoSuchProjectError
@@ -152,6 +152,20 @@ class Command:
             self._Options(self._optparse)
         return self._optparse
 
+    @staticmethod
+    def _GetHelpForCpuJobCount(
+        default_jobs: Optional[int] = None,
+    ) -> str:
+        """Return CPU-based job help, with an explicit default when needed.
+
+        Specify default_jobs when additional logic computes effective default.
+        """
+        if GENERATE_MANPAGES:
+            return "based on number of CPU cores"
+
+        default = "%default" if default_jobs is None else str(default_jobs)
+        return f"{default}; based on number of CPU cores"
+
     def _CommonOptions(self, p, opt_v=True):
         """Initialize the option parser with common options.
 
@@ -176,11 +190,7 @@ class Command:
         )
 
         if self.PARALLEL_JOBS is not None:
-            default = "based on number of CPU cores"
+            default = self._GetHelpForCpuJobCount()
-            if not GENERATE_MANPAGES:
-                # Only include active cpu count if we aren't generating man
-                # pages.
-                default = f"%default; {default}"
             p.add_option(
                 "-j",
                 "--jobs",
@@ -398,7 +408,11 @@ class Command:
         Args:
             args: a list of (case-insensitive) strings, projects to search for.
             manifest: an XmlManifest, the manifest to use, or None for default.
-            groups: a string, the manifest groups in use.
+            groups: a string, the manifest group selection to apply.
+                Non-empty values apply to all candidate projects in this call.
+                When empty or omitted, single-manifest calls use the selected
+                manifest's effective groups; all-manifest calls use each
+                candidate project's owning manifest's effective groups.
             missing_ok: a boolean, whether to allow missing projects.
             submodules_ok: whether to allow submodules. True allows them for
                 all projects, False disallows them for all projects, and None
@@ -425,9 +439,33 @@ class Command:
                 return project.sync_s
             return submodules_ok
 
-        if not groups:
+        def parse_groups(value: str) -> List[str]:
-            groups = manifest.GetManifestGroupsStr()
+            return [x for x in re.split(r"[,\s]+", value) if x]
-        groups = [x for x in re.split(r"[,\s]+", groups) if x]
+
+        if groups:
+            groups_for_all_projects = parse_groups(groups)
+        elif all_manifests:
+            # In all-manifest mode, each project uses its owning
+            # manifest's effective groups.
+            groups_for_all_projects = None
+        else:
+            groups_for_all_projects = parse_groups(
+                manifest.GetManifestGroupsStr()
+            )
+
+        groups_by_manifest = {}
+
+        def matches_groups(project: "Project") -> bool:
+            if groups_for_all_projects is not None:
+                return project.MatchesGroups(groups_for_all_projects)
+
+            project_manifest = project.manifest
+            if project_manifest not in groups_by_manifest:
+                groups_by_manifest[project_manifest] = parse_groups(
+                    project_manifest.GetManifestGroupsStr()
+                )
+
+            return project.MatchesGroups(groups_by_manifest[project_manifest])
 
         if not args:
             derived_projects = {}
@@ -439,9 +477,7 @@ class Command:
                     )
             all_projects_list.extend(derived_projects.values())
             for project in all_projects_list:
-                if (missing_ok or project.Exists) and project.MatchesGroups(
+                if (missing_ok or project.Exists) and matches_groups(project):
-                    groups
-                ):
                     result.append(project)
         else:
             self._ResetPathToProjectMap(all_projects_list)
@@ -455,7 +491,7 @@ class Command:
                     for project in manifest.GetProjectsWithName(
                         arg, all_manifests=all_manifests
                     )
-                    if project.MatchesGroups(groups)
+                    if matches_groups(project)
                 ]
 
                 if not projects:
@@ -498,7 +534,7 @@ class Command:
                             "%s (%s)"
                             % (arg, project.RelPath(local=not all_manifests))
                         )
-                    if not project.MatchesGroups(groups):
+                    if not matches_groups(project):
                         raise InvalidProjectGroupsError(arg)
 
                 result.extend(projects)
@@ -509,7 +545,14 @@ class Command:
         result.sort(key=_getpath)
         return result
 
-    def FindProjects(self, args, inverse=False, all_manifests=False):
+    def FindProjects(
+        self,
+        args: List[str],
+        inverse: bool = False,
+        all_manifests: bool = False,
+        groups: Optional[str] = "",
+        missing_ok: Optional[bool] = False,
+    ) -> List["Project"]:
         """Find projects from command line arguments.
 
         Args:
@@ -519,10 +562,18 @@ class Command:
             all_manifests: a boolean, if True then all manifests and
                 submanifests are used. If False, then only the local
                 (sub)manifest is used.
+            groups: a string specifying manifest groups. If empty or None, use
+                each manifest's effective groups.
+            missing_ok: a boolean, whether to allow missing projects.
         """
         result = []
         patterns = [re.compile(r"%s" % a, re.IGNORECASE) for a in args]
-        for project in self.GetProjects("", all_manifests=all_manifests):
+        for project in self.GetProjects(
+            "",
+            groups=groups,
+            missing_ok=missing_ok,
+            all_manifests=all_manifests,
+        ):
             paths = [project.name, project.RelPath(local=not all_manifests)]
             for pattern in patterns:
                 match = any(pattern.search(x) for x in paths)

completion.zsh

@@ -400,6 +400,7 @@ _repo() {
         '--no-verify[Do not verify]' \
         '--verify[Verify]' \
         '--ignore-hooks[Ignore hooks]' \
+        '--fix[Automatically fix]' \
         '*: :->project'
       ;;
     version)

docs/fetch-cmd.md

@@ -6,6 +6,9 @@ executed during `repo sync` to fetch objects, instead of using standard
 filesystems or lazy checkouts where fetching metadata and downloading file
 contents should be decoupled.
 
+The checkout half of a sync has a counterpart, `repo.reprojectcmd`; see
+`docs/reproject-cmd.md`.
+
 ## Configuration
 
 To use this feature, set the following in `.repo/manifests.git/config`:

docs/repo-hooks.md

@@ -88,7 +88,14 @@ be useful when deploying automatic fixes.
 If the repo command that triggered the hook supports a "yes" option (e.g.,
 `repo upload --yes`), this option is propagated to the hook's `main` function
 as `yes` parameter (defaulting to `False`).  Hooks can use this to bypass
-interactive confirmation prompts when they can automatically fix issues.
+interactive confirmation prompts for safe non-modifying operations.
+
+### Automated Fixes
+
+If the repo command that triggered the hook supports a "fix" option (e.g.,
+`repo upload --fix`), this option is propagated to the hook's `main` function
+as `fix` parameter (defaulting to `False`).  Hooks can use this to automatically
+apply fixes without prompting the user.
 
 ### Shebang Handling
 
@@ -126,7 +133,7 @@ This hook runs when people run `repo upload`.
 The `pre-upload.py` file should be defined like:
 
 ```py
-def main(project_list, worktree_list=None, yes=False, **kwargs):
+def main(project_list, worktree_list=None, fix=False, yes=False, **kwargs):
     """Main function invoked directly by repo.
 
     We must use the name "main" as that is what repo requires.
@@ -137,6 +144,7 @@ def main(project_list, worktree_list=None, yes=False, **kwargs):
           project_list, so that each entry in project_list matches with a
           directory in worktree_list.  If None, we will attempt to calculate
           the directories automatically.
+      fix: Whether to automatically apply fixes without prompting.
       yes: Whether to answer yes to all safe prompts (see
           [Safe Prompts](#safe-prompts)).
       kwargs: Leave this here for forward-compatibility.

docs/reproject-cmd.md

@@ -0,0 +1,126 @@
+# Reproject Command Contract
+
+The `repo.reprojectcmd` configuration names a command that `repo sync` runs
+instead of Git to move a project's index and worktree to the tree of the
+target commit. It is the checkout-side counterpart of `repo.fetchcmd` (see
+`docs/fetch-cmd.md`): together they let an external tool take over both the
+network fetch and the materialization of a project. This is useful on
+virtualized filesystems that address content by hash, where a tree can be
+materialized far faster than `git checkout` can write every file.
+
+The command only materializes the tree. `repo` then makes the ref write that
+Git would have made, using `git update-ref`.
+
+## Configuration
+
+To use this feature, set the following in `.repo/manifests.git/config`:
+```ini
+[repo]
+	reprojectcmd = "your custom command here"
+	uselocalgitdirs = true
+```
+Setting `repo.reprojectcmd` **requires** `repo.uselocalgitdirs` to be set to
+`true`.
+
+For reference, this command does with Git what `repo` would otherwise do
+itself:
+```ini
+[repo]
+	reprojectcmd = "git -C $REPO_PATH read-tree -m -u $REPO_TREV"
+	uselocalgitdirs = true
+```
+The one-tree merge applies the change to the target, keeps local changes to
+every other path, and refuses to overwrite a modified or untracked file, so it
+enforces the preconditions below by itself. It also works for a project that
+has nothing checked out yet.
+
+## Environment Variables
+
+The command is executed in a subshell, from the root of the client, populated
+with standard project-context environment variables. For details on standard
+variables (such as `REPO_PROJECT`, `REPO_PATH`, `REPO_REMOTE`, etc.), see the
+Environment section in `repo help forall` or `subcmds/forall.py`.
+
+The variables the command typically needs are:
+
+*   `REPO_PATH`: The project path relative to the root of the client.
+*   `REPO_TREV`: The target revision resolved to a full commit hash. Match this
+    commit's tree.
+
+There is no force mode: a project that would need one never reaches the
+command (see the preconditions below).
+
+## When the command runs
+
+`repo sync` already classifies each project and picks a Git operation. The
+command replaces the three that are a materialization of a target tree:
+
+1.  The checkout that detaches HEAD at the target. This is the common case: a
+    project on a detached HEAD, a project on a branch that does not track
+    upstream, and `repo sync -d`.
+2.  The fast-forward of the checked out branch to the target.
+3.  The hard reset of the checked out branch to the target, when the commits
+    it carried were dropped upstream.
+
+After the command exits 0, `repo` writes the ref itself: it detaches `HEAD` at
+`REPO_TREV`, or moves the checked out branch to `REPO_TREV`.
+
+The command is **not** run:
+
+*   When `HEAD` already names `REPO_TREV`.
+*   At the fast-forward step when `HEAD` is ahead of `REPO_TREV`, where Git's
+    merge would be a no-op.
+*   For a rebase. A branch carrying local commits has them replayed onto the
+    target by `git rebase`, which is not a materialization of a target tree.
+*   For `MetaProject`s (i.e. the internal `repo` repository itself at
+    `.repo/repo` and the `manifests` repository at `.repo/manifests`).
+
+## Contract
+
+### Preconditions
+
+Before invoking the command, `repo` ensures that:
+
+*   The index has no staged changes (the index matches `HEAD`, or is empty on an unborn `HEAD`).
+*   No rebase, cherry-pick, merge, or revert is in progress.
+
+Detecting collisions with untracked files or unstaged working-tree modifications is the responsibility of the reproject command itself (e.g. via `git read-tree -m -u $REPO_TREV` or a custom virtual filesystem checkout tool). If local changes collide with the target tree, the command must abort with a non-zero exit code. Local modifications and untracked files outside the diff between `HEAD` and `REPO_TREV` must be preserved.
+
+### Postconditions on exit 0
+
+After the command exits with status 0, `repo` expects the following
+postconditions to be met:
+
+1.  `git diff-index --quiet --cached REPO_TREV^{tree}` exits 0 (the index
+    matches the target tree).
+2.  `HEAD` still names what it did before the command, and its resolved commit
+    object ID has not changed.
+
+### Invariants
+
+The command may modify the worktree and the index, and may write project-local
+Git config. The command must:
+
+*   Apply the change from `HEAD`'s tree to `REPO_TREV`'s tree and leave every
+    other path alone. Local modifications and untracked files outside that
+    change must survive: the command applies a diff, it does not reset the
+    tree.
+*   Not write any ref, including `HEAD` and `ORIG_HEAD`. `repo` owns every ref
+    write.
+*   Not create or replace `.git/`, and not touch anything under `.repo/`.
+*   Not require the Git remote, to preserve `repo sync --local-only`.
+*   Be idempotent. Running it twice on the same target is a no-op.
+
+### Failure
+
+*   A non-zero exit status, a failed precondition or a failed postcondition
+    fails that project's sync, and the command's or Git's output is surfaced
+    to the user.
+*   Other projects continue, and `repo sync` exits non-zero.
+
+## Limitations
+
+Nested projects are out of scope: a project whose path lies inside another
+project's path, a `<project>` nested in another `<project>` in the manifest,
+and a submodule discovered with `sync-s` or `--recurse-submodules`. `repo sync`
+fails if the manifest has one while `repo.reprojectcmd` is set.

git_command.py

@@ -70,6 +70,19 @@ class _GitCall:
 git = _GitCall()
 
 
+def IsValidBranchName(name: str) -> bool:
+    """Return whether |name| is valid where Git expects a branch name."""
+    p = GitCommand(
+        None,
+        ["check-ref-format", "--branch", name],
+        capture_stdout=True,
+        capture_stderr=True,
+        add_event_log=False,
+        log_as_error=False,
+    )
+    return p.Wait() == 0
+
+
 def RepoSourceVersion():
     """Return the version of the repo.git tree."""
     ver = getattr(RepoSourceVersion, "version", None)
@@ -270,6 +283,7 @@ class GitCommand:
         bare=False,
         input=None,
         capture_stdout=False,
+        capture_stdout_bytes: bool = False,
         capture_stderr=False,
         merge_output=False,
         disable_editor=False,
@@ -291,6 +305,12 @@ class GitCommand:
         self.cmdv = cmdv
         self.verify_command = verify_command
         self.stdout, self.stderr = None, None
+        if capture_stdout_bytes:
+            if merge_output:
+                raise ValueError(
+                    "capture_stdout_bytes cannot be combined with merge_output"
+                )
+            capture_stdout = True
 
         # Git on Windows wants its paths only using / for reliability.
         if platform_utils.isWindows():
@@ -334,6 +354,7 @@ class GitCommand:
                 command,
                 env,
                 capture_stdout=capture_stdout,
+                capture_stdout_bytes=capture_stdout_bytes,
                 capture_stderr=capture_stderr,
                 merge_output=merge_output,
                 ssh_proxy=ssh_proxy,
@@ -367,6 +388,7 @@ class GitCommand:
         command,
         env,
         capture_stdout=False,
+        capture_stdout_bytes: bool = False,
         capture_stderr=False,
         merge_output=False,
         ssh_proxy=None,
@@ -399,6 +421,10 @@ class GitCommand:
         # See go/tee-repo-stderr for more context.
         tee_stderr = False
         kwargs = {"encoding": "utf-8", "errors": "backslashreplace"}
+        if capture_stdout_bytes:
+            kwargs = {}
+            if isinstance(input, str):
+                input = input.encode("utf-8", "surrogateescape")
         if not (stdin or stdout or stderr):
             tee_stderr = True
             # stderr will be written back to sys.stderr even though it is
@@ -477,6 +503,10 @@ class GitCommand:
                     self.stderr = self._Tee(p.stderr, sys.stderr)
                 else:
                     self.stdout, self.stderr = p.communicate(input=input)
+                    if capture_stdout_bytes and isinstance(self.stderr, bytes):
+                        self.stderr = self.stderr.decode(
+                            "utf-8", "backslashreplace"
+                        ).replace("\r\n", "\n")
             finally:
                 if ssh_proxy:
                     ssh_proxy.remove_client(p)
@@ -528,17 +558,35 @@ class GitCommand:
             env.pop(key, None)
         return env
 
-    def VerifyCommand(self):
+    def VerifyCommand(self) -> None:
         if self.rc == 0:
             return None
-        stdout = (
+        raw_stdout = self.stdout
-            "\n".join(self.stdout.split("\n")[:GIT_ERROR_STDOUT_LINES])
+        if isinstance(raw_stdout, bytes):
-            if self.stdout
+            first_records = re.split(
-            else None
+                rb"\r\n|[\r\n\0]", raw_stdout, maxsplit=GIT_ERROR_STDOUT_LINES
-        )
+            )[:GIT_ERROR_STDOUT_LINES]
+            stdout = (
+                "\n".join(
+                    r.decode("utf-8", "backslashreplace") for r in first_records
+                )
+                if raw_stdout
+                else None
+            )
+        elif raw_stdout:
+            first_records = re.split(
+                r"\r\n|[\r\n\0]", raw_stdout, maxsplit=GIT_ERROR_STDOUT_LINES
+            )[:GIT_ERROR_STDOUT_LINES]
+            stdout = "\n".join(first_records)
+        else:
+            stdout = None
+
+        raw_stderr = self.stderr
+        if isinstance(raw_stderr, bytes):
+            raw_stderr = raw_stderr.decode("utf-8", "backslashreplace")
         stderr = (
-            "\n".join(self.stderr.split("\n")[:GIT_ERROR_STDERR_LINES])
+            "\n".join(raw_stderr.split("\n")[:GIT_ERROR_STDERR_LINES])
-            if self.stderr
+            if raw_stderr
             else None
         )
         project = self.project.name if self.project else None

git_config.py

@@ -40,7 +40,7 @@ from repo_trace import Trace
 # that is saved in the config.
 SYNC_STATE_PREFIX = "repo.syncstate."
 
-ID_RE = re.compile(r"^[0-9a-f]{40,64}$")
+ID_RE = re.compile(r"^(?:[0-9a-f]{40}|[0-9a-f]{64})$")
 
 REVIEW_CACHE = {}
 

git_refs.py

@@ -14,6 +14,7 @@
 
 import os
 
+from git_command import git_require
 from git_command import GitCommand
 import platform_utils
 from repo_trace import Trace
@@ -41,6 +42,17 @@ class GitRefs:
         self._EnsureLoaded()
         return self._phyref
 
+    @property
+    def head(self) -> str:
+        """Return HEAD's symbolic target or detached object ID."""
+        self._EnsureLoaded()
+        return self._symref.get(HEAD) or self._phyref.get(HEAD, "")
+
+    @property
+    def is_loaded(self) -> bool:
+        """Whether a ref snapshot has already been loaded."""
+        return self._phyref is not None
+
     def get(self, name):
         try:
             return self.all[name]
@@ -87,8 +99,12 @@ class GitRefs:
             self._symref = {}
             self._mtime = {}
 
-            self._ReadRefs()
+            root_refs_loaded = self._ReadRefs()
-            self._ReadSymbolicRef(HEAD)
+            if not root_refs_loaded or (
+                HEAD not in self._phyref and HEAD not in self._symref
+            ):
+                # --include-root-refs does not report an unborn HEAD.
+                self._ReadSymbolicRef(HEAD)
 
             scan = self._symref
             attempts = 0
@@ -113,18 +129,32 @@ class GitRefs:
         """Check if a ref_id is a null object ID."""
         return ref_id and all(ch == "0" for ch in ref_id)
 
-    def _ReadRefs(self) -> None:
+    def _ReadRefs(self) -> bool:
-        """Read all references using git for-each-ref."""
+        """Read all references using git for-each-ref.
+
+        Returns:
+            Whether root refs, including HEAD when it exists, were loaded.
+        """
+        include_root_refs = git_require((2, 45, 0))
+        cmd = [
+            "for-each-ref",
+            "--format=%(objectname)%00%(refname)%00%(symref)",
+        ]
+        if include_root_refs:
+            cmd.insert(1, "--include-root-refs")
+            # Avoid caching volatile root refs such as ORIG_HEAD.  HEAD and
+            # refs/* are the only namespaces GitRefs exposes to callers.
+            cmd.extend([HEAD, "refs"])
         p = GitCommand(
             None,
-            ["for-each-ref", "--format=%(objectname)%00%(refname)%00%(symref)"],
+            cmd,
             capture_stdout=True,
             capture_stderr=True,
             bare=True,
             gitdir=self._gitdir,
         )
         if p.Wait() != 0:
-            return
+            return False
 
         for line in p.stdout.splitlines():
             ref_id, name, symref = line.split("\0")
@@ -132,6 +162,7 @@ class GitRefs:
                 self._symref[name] = symref
             elif ref_id and not self._IsNullRef(ref_id):
                 self._phyref[name] = ref_id
+        return include_root_refs
 
     def _ReadSymbolicRef(self, name: str) -> None:
         """Read a symbolic reference."""

git_status.py

@@ -0,0 +1,259 @@
+# Copyright (C) 2026 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Read a worktree's state from one machine-readable git status snapshot."""
+
+from collections import OrderedDict
+import os
+from typing import Iterator, List, Optional, TYPE_CHECKING
+
+from git_command import git_require
+from git_command import GitCommand
+
+
+if TYPE_CHECKING:
+    from project import Project
+
+
+class StatusEntry:
+    """The state of one path on one side of the index."""
+
+    def __init__(
+        self,
+        path: str,
+        status: str,
+        src_path: Optional[str] = None,
+        level: Optional[str] = None,
+    ) -> None:
+        self.path = path
+        self.status = status
+        self.src_path = src_path
+        self.level = level
+
+
+class StatusSnapshot:
+    """A consistent view of worktree, index, and branch state."""
+
+    def __init__(self) -> None:
+        self.index_changes = OrderedDict()
+        self.worktree_changes = OrderedDict()
+        self.untracked = []
+        self.branch_oid = None
+        self.branch_head = None
+        self.upstream = None
+        self.ahead = 0
+        self.behind = 0
+        self.has_ahead_behind = False
+        self.stash_count = 0
+
+    @property
+    def current_branch(self) -> Optional[str]:
+        if self.branch_head in (None, "(detached)", "(unknown)"):
+            return None
+        return self.branch_head
+
+    def is_dirty(self, consider_untracked: bool = True) -> bool:
+        return bool(
+            self.index_changes
+            or self.worktree_changes
+            or (consider_untracked and self.untracked)
+        )
+
+
+def GetStatus(
+    project: "Project",
+    gitdir: str,
+    untracked_files: str = "all",
+    branch: bool = False,
+    ahead_behind: bool = False,
+    show_stash: bool = False,
+) -> StatusSnapshot:
+    """Return one machine-readable status snapshot for |project|."""
+    if not git_require((2, 11, 0)):
+        raise UnsupportedStatusError("porcelain v2 requires Git 2.11")
+    cmd = [
+        "status",
+        "--porcelain=v2",
+        "-z",
+        "--ignore-submodules=all",
+        f"--untracked-files={untracked_files}",
+    ]
+    if branch:
+        cmd.append("--branch")
+        if git_require((2, 17, 0)):
+            cmd.append(
+                "--ahead-behind" if ahead_behind else "--no-ahead-behind"
+            )
+    if git_require((2, 18, 0)):
+        # Match the existing staged diff's explicit rename detection even if
+        # status.renames is disabled in the user's config.
+        cmd.append("--renames")
+    if show_stash and git_require((2, 35, 0)):
+        cmd.append("--show-stash")
+
+    p = GitCommand(
+        project,
+        cmd,
+        bare=False,
+        gitdir=gitdir,
+        capture_stdout=True,
+        capture_stdout_bytes=True,
+        capture_stderr=True,
+        verify_command=True,
+    )
+    p.Wait()
+    return ParsePorcelainV2(p.stdout)
+
+
+def _Path(value: bytes) -> str:
+    """Decode a Git pathname without losing undecodable bytes."""
+    return os.fsdecode(value)
+
+
+def _Status(value: int) -> str:
+    """Normalize Git's unchanged markers for repo's status display."""
+    char = chr(value)
+    return "" if char == "." else char
+
+
+def _Records(output: bytes) -> Iterator[bytes]:
+    if not output:
+        return iter(())
+    if not output.endswith(b"\0"):
+        raise StatusParseError("porcelain v2 output is not NUL terminated")
+    records = output.split(b"\0")
+    if not records[-1]:
+        records.pop()
+    return iter(records)
+
+
+class StatusParseError(ValueError):
+    """Raised when machine-readable status output is malformed."""
+
+
+class UnsupportedStatusError(RuntimeError):
+    """Raised when the Git client cannot produce porcelain v2."""
+
+
+def _Fields(record: bytes, count: int) -> List[bytes]:
+    fields = record.split(b" ", count - 1)
+    if len(fields) != count:
+        raise StatusParseError(f"malformed porcelain v2 record: {record!r}")
+    return fields
+
+
+def _AddTracked(
+    status: StatusSnapshot,
+    path: str,
+    xy: bytes,
+    src_path: Optional[str] = None,
+    level: Optional[str] = None,
+) -> None:
+    index_status = _Status(xy[0])
+    worktree_status = _Status(xy[1])
+    if index_status:
+        status.index_changes[path] = StatusEntry(
+            path,
+            index_status,
+            src_path=src_path if index_status in ("R", "C") else None,
+            level=level if index_status in ("R", "C") else None,
+        )
+    if worktree_status:
+        status.worktree_changes[path] = StatusEntry(
+            path,
+            worktree_status,
+            src_path=src_path if worktree_status in ("R", "C") else None,
+            level=level if worktree_status in ("R", "C") else None,
+        )
+
+
+def ParsePorcelainV2(output: bytes) -> StatusSnapshot:
+    """Parse ``git status --porcelain=v2 -z --branch`` output."""
+    status = StatusSnapshot()
+    records = _Records(output)
+    for record in records:
+        kind = record[:1]
+        if kind == b"#":
+            try:
+                key, value = record[2:].split(b" ", 1)
+            except ValueError as e:
+                raise StatusParseError(
+                    f"malformed porcelain v2 header: {record!r}"
+                ) from e
+            if key == b"branch.oid":
+                value = value.decode("ascii")
+                status.branch_oid = None if value == "(initial)" else value
+            elif key == b"branch.head":
+                status.branch_head = _Path(value)
+            elif key == b"branch.upstream":
+                status.upstream = _Path(value)
+            elif key == b"branch.ab":
+                try:
+                    value = value.decode("ascii")
+                    ahead, behind = value.split()
+                    if ahead != "+?" and behind != "-?":
+                        status.ahead = int(ahead)
+                        status.behind = -int(behind)
+                        status.has_ahead_behind = True
+                except ValueError as e:
+                    raise StatusParseError(
+                        f"malformed porcelain v2 branch.ab record: {record!r}"
+                    ) from e
+            elif key == b"stash":
+                status.stash_count = int(value.decode("ascii"))
+            continue
+
+        if kind == b"1":
+            fields = _Fields(record, 9)
+            xy = fields[1]
+            if len(xy) != 2:
+                raise StatusParseError(f"invalid status pair: {xy!r}")
+            path = _Path(fields[8])
+            _AddTracked(status, path, xy)
+        elif kind == b"2":
+            fields = _Fields(record, 10)
+            xy = fields[1]
+            if len(xy) != 2:
+                raise StatusParseError(f"invalid status pair: {xy!r}")
+            score = fields[8][1:].lstrip(b"0") or b"0"
+            try:
+                src_path = _Path(next(records))
+            except StopIteration as e:
+                raise StatusParseError(
+                    "rename record has no source path"
+                ) from e
+            path = _Path(fields[9])
+            _AddTracked(
+                status,
+                path,
+                xy,
+                src_path=src_path,
+                level=score.decode("ascii"),
+            )
+        elif kind == b"u":
+            fields = _Fields(record, 11)
+            path = _Path(fields[10])
+            # The old diff-index/diff-files pair reported unmerged paths on
+            # both sides, regardless of porcelain's more specific XY pair.
+            status.index_changes[path] = StatusEntry(path, "U")
+            status.worktree_changes[path] = StatusEntry(path, "U")
+        elif kind == b"?":
+            status.untracked.append(_Path(record[2:]))
+        elif kind == b"!":
+            continue
+        else:
+            raise StatusParseError(
+                f"unknown porcelain v2 record type: {record!r}"
+            )
+    return status

git_superproject.py

@@ -36,7 +36,6 @@ from git_command import git_require
 from git_command import GitCommand
 from git_config import IsId
 from git_config import RepoConfig
-from git_refs import GitRefs
 import platform_utils
 
 
@@ -189,7 +188,7 @@ class Superproject:
             if netloc:
                 parts = netloc.split("-review", 1)
                 host = parts[0]
-                rev = GitRefs(self._work_git).get("HEAD")
+                rev = self._GetRef("HEAD")
                 return f"{host}/{self.name}@{rev}"
         return None
 
@@ -314,7 +313,10 @@ class Superproject:
         # We use --negotiation-tip to speed up the fetch. Superproject branches
         # do not share commits. So this lets git know it only needs to send
         # commits reachable from the specified local refs.
-        rev_commit = GitRefs(self._work_git).get(f"refs/heads/{self.revision}")
+        negotiation_ref = self.revision
+        if negotiation_ref and not negotiation_ref.startswith("refs/"):
+            negotiation_ref = f"refs/heads/{negotiation_ref}"
+        rev_commit = self._GetRef(negotiation_ref) if negotiation_ref else ""
         if rev_commit:
             cmd.extend(["--negotiation-tip", rev_commit])
 
@@ -347,6 +349,21 @@ class Superproject:
             return False
         return True
 
+    def _GetRef(self, ref: str) -> str:
+        """Resolve one local ref without loading the entire ref namespace."""
+        p = GitCommand(
+            None,
+            ["rev-parse", "--verify", "--quiet", ref],
+            gitdir=self._work_git,
+            bare=True,
+            capture_stdout=True,
+            capture_stderr=True,
+            log_as_error=False,
+        )
+        if p.Wait() == 0:
+            return p.stdout.strip()
+        return ""
+
     def _LsTree(self):
         """Gets the commit ids for all projects.
 

hooks.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import optparse
 import os
 import re
 import sys
@@ -69,6 +70,7 @@ class RepoHook:
         ignore_hooks=False,
         abort_if_user_denies=False,
         yes=False,
+        fix=False,
     ):
         """RepoHook constructor.
 
@@ -91,6 +93,7 @@ class RepoHook:
             abort_if_user_denies: If True, we'll abort running the hook if the
                 user doesn't allow us to run the hook.
             yes: If True, then 'Yes' is assumed for any prompts.
+            fix: If True, then 'Fix' is assumed for any fixup prompts.
         """
         self._hook_type = hook_type
         self._hooks_project = hooks_project
@@ -102,6 +105,7 @@ class RepoHook:
         self._ignore_hooks = ignore_hooks
         self._abort_if_user_denies = abort_if_user_denies
         self._yes = yes
+        self._fix = fix
 
         # Store the full path to the script for convenience.
         self._script_fullpath = None
@@ -380,6 +384,7 @@ class RepoHook:
             kwargs = {
                 **kwargs,
                 "hook_should_take_kwargs": True,
+                "fix": self._fix,
                 "yes": self._yes,
             }
 
@@ -504,12 +509,17 @@ class RepoHook:
                 ).url,
                 "bug_url": manifest.contactinfo.bugurl,
                 "yes": getattr(opt, "yes", False),
+                "fix": getattr(opt, "fix", False),
             }
         )
         return cls(*args, **kwargs)
 
     @staticmethod
-    def AddOptionGroup(parser, name):
+    def AddOptionGroup(
+        parser: optparse.OptionParser,
+        name: str,
+        allow_fix: bool = False,
+    ) -> None:
         """Help options relating to the various hooks."""
 
         # Note that verify and no-verify are NOT opposites of each other, which
@@ -533,3 +543,10 @@ class RepoHook:
             action="store_true",
             help="Do not abort if %s hooks fail." % name,
         )
+        if allow_fix:
+            group.add_option(
+                "--fix",
+                action="store_true",
+                default=False,
+                help="Automatically apply %s fixes without prompting." % name,
+            )

main.py

@@ -104,6 +104,11 @@ elif sys.version_info < MIN_PYTHON_VERSION_SOFT:
 KEYBOARD_INTERRUPT_EXIT = 128 + signal.SIGINT
 MAX_PRINT_ERRORS = 5
 
+if hasattr(sys.stdout, "reconfigure"):
+    sys.stdout.reconfigure(errors="surrogateescape")
+if hasattr(sys.stderr, "reconfigure"):
+    sys.stderr.reconfigure(errors="surrogateescape")
+
 global_options = optparse.OptionParser(
     usage="repo [-p|--paginate|--no-pager] COMMAND [ARGS]",
     add_help_option=False,

man/repo-smartsync.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "July 2026" "repo smartsync" "Repo Manual"
+.TH REPO "1" "September 2026" "repo smartsync" "Repo Manual"
 .SH NAME
 repo \- repo smartsync - manual page for repo smartsync
 .SH SYNOPSIS
@@ -21,7 +21,7 @@ number of jobs to run in parallel (default: based on number of CPU cores)
 number of network jobs to run in parallel (defaults to \fB\-\-jobs\fR or 1). Ignored unless \fB\-\-no\-interleaved\fR is set
 .TP
 \fB\-\-jobs\-checkout\fR=\fI\,JOBS\/\fR
-number of local checkout jobs to run in parallel (defaults to \fB\-\-jobs\fR or 8). Ignored unless \fB\-\-no\-interleaved\fR is set
+number of local checkout jobs to run in parallel (defaults to \fB\-\-jobs\fR or based on number of CPU cores). Ignored unless \fB\-\-no\-interleaved\fR is set
 .TP
 \fB\-f\fR, \fB\-\-force\-broken\fR
 obsolete option (to be deleted in the future)

man/repo-sync.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "July 2026" "repo sync" "Repo Manual"
+.TH REPO "1" "September 2026" "repo sync" "Repo Manual"
 .SH NAME
 repo \- repo sync - manual page for repo sync
 .SH SYNOPSIS
@@ -21,7 +21,7 @@ number of jobs to run in parallel (default: based on number of CPU cores)
 number of network jobs to run in parallel (defaults to \fB\-\-jobs\fR or 1). Ignored unless \fB\-\-no\-interleaved\fR is set
 .TP
 \fB\-\-jobs\-checkout\fR=\fI\,JOBS\/\fR
-number of local checkout jobs to run in parallel (defaults to \fB\-\-jobs\fR or 8). Ignored unless \fB\-\-no\-interleaved\fR is set
+number of local checkout jobs to run in parallel (defaults to \fB\-\-jobs\fR or based on number of CPU cores). Ignored unless \fB\-\-no\-interleaved\fR is set
 .TP
 \fB\-f\fR, \fB\-\-force\-broken\fR
 obsolete option (to be deleted in the future)

man/repo-upload.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "June 2026" "repo upload" "Repo Manual"
+.TH REPO "1" "August 2026" "repo upload" "Repo Manual"
 .SH NAME
 repo \- repo upload - manual page for repo upload
 .SH SYNOPSIS
@@ -112,6 +112,9 @@ Run the pre\-upload hook without prompting.
 .TP
 \fB\-\-ignore\-hooks\fR
 Do not abort if pre\-upload hooks fail.
+.TP
+\fB\-\-fix\fR
+Automatically apply pre\-upload fixes without prompting.
 .PP
 Run `repo help upload` to view the detailed manual.
 .SH DETAILS

manifest_xml.py

@@ -692,9 +692,9 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
                 e.setAttribute("remote", remoteName)
             if peg_rev:
                 if self.IsMirror:
-                    value = p.bare_git.rev_parse(p.revisionExpr + "^0")
+                    value = p.bare_git.ResolveCommit(p.revisionExpr)
                 else:
-                    value = p.work_git.rev_parse(HEAD + "^0")
+                    value = p.work_git.ResolveCommit(HEAD)
                 e.setAttribute("revision", value)
                 if peg_rev_upstream:
                     if p.upstream:
@@ -1519,9 +1519,9 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
                         if base_revision:
                             if p.revisionExpr != base_revision:
                                 failed_revision_changes.append(
-                                    "extend-project name %s mismatch base "
+                                    f"extend-project name {name}:\n  "
-                                    "%s vs revision %s"
+                                    f"base {base_revision} vs "
-                                    % (name, base_revision, p.revisionExpr)
+                                    f"revision {p.revisionExpr}"
                                 )
                         p.SetRevision(revision)
 
@@ -1622,9 +1622,9 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
                             if base_revision:
                                 if p.revisionExpr != base_revision:
                                     failed_revision_changes.append(
-                                        "remove-project name %s mismatch base "
+                                        f"remove-project name {name}:\n  "
-                                        "%s vs revision %s"
+                                        f"base {base_revision} vs "
-                                        % (name, base_revision, p.revisionExpr)
+                                        f"revision {p.revisionExpr}"
                                     )
                             del self._paths[p.relpath]
                             if not removed_project:
@@ -1636,13 +1636,9 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
                             if base_revision:
                                 if p.revisionExpr != base_revision:
                                     failed_revision_changes.append(
-                                        "remove-project path %s mismatch base "
+                                        f"remove-project path {p.relpath}:\n  "
-                                        "%s vs revision %s"
+                                        f"base {base_revision} vs "
-                                        % (
+                                        f"revision {p.revisionExpr}"
-                                            p.relpath,
-                                            base_revision,
-                                            p.revisionExpr,
-                                        )
                                     )
                             self._projects[projname].remove(p)
                             del self._paths[p.relpath]
@@ -1664,10 +1660,10 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
                     )
 
         if failed_revision_changes:
+            fail_string = "\n".join(failed_revision_changes)
             raise ManifestParseError(
-                "revision base check failed, rebase patches and update "
+                f"detected base-revision mismatch, updates needed:\n"
-                "base revs for: ",
+                f"{fail_string}",
-                failed_revision_changes,
             )
 
         # Store repo hooks project information.

release/update-manpages

@@ -23,4 +23,5 @@ import sys
 import update_manpages
 
 
-sys.exit(update_manpages.main(sys.argv[1:]))
+if __name__ == "__main__":
+    sys.exit(update_manpages.main(sys.argv[1:]))

subcmds/abandon.py

@@ -20,7 +20,7 @@ from command import Command
 from command import DEFAULT_LOCAL_JOBS
 from error import RepoError
 from error import RepoExitError
-from git_command import git
+from git_command import IsValidBranchName
 from progress import Progress
 from repo_logging import RepoLogger
 
@@ -58,9 +58,7 @@ It is equivalent to "git branch -D <branchname>".
 
         if not opt.all:
             branches = args[0].split()
-            invalid_branches = [
+            invalid_branches = [x for x in branches if not IsValidBranchName(x)]
-                x for x in branches if not git.check_ref_format(f"heads/{x}")
-            ]
 
             if invalid_branches:
                 self.OptionParser.error(

subcmds/cherry_pick.py

@@ -14,6 +14,7 @@
 
 import re
 import sys
+from typing import Tuple
 
 from command import Command
 from error import GitError
@@ -43,36 +44,8 @@ change id will be added.
 
     def Execute(self, opt, args):
         reference = args[0]
-
+        sha1, commit = self._ResolveReference(reference)
-        p = GitCommand(
+        old_msg = self._StripHeader(commit)
-            None,
-            ["rev-parse", "--verify", reference],
-            capture_stdout=True,
-            capture_stderr=True,
-            verify_command=True,
-        )
-        try:
-            p.Wait()
-        except GitError:
-            logger.error(p.stderr)
-            raise
-
-        sha1 = p.stdout.strip()
-
-        p = GitCommand(
-            None,
-            ["cat-file", "commit", sha1],
-            capture_stdout=True,
-            verify_command=True,
-        )
-
-        try:
-            p.Wait()
-        except GitError:
-            logger.error("error: Failed to retrieve old commit message")
-            raise
-
-        old_msg = self._StripHeader(p.stdout)
 
         p = GitCommand(
             None,
@@ -117,6 +90,48 @@ change id will be added.
             logger.error("error: Failed to update commit message")
             raise
 
+    def _ResolveReference(self, reference: str) -> Tuple[str, str]:
+        """Resolve a commit and read it through one cat-file batch request."""
+        expression = f"{reference}^{{commit}}"
+        p = GitCommand(
+            None,
+            ["cat-file", "--batch"],
+            input=expression + "\n",
+            capture_stdout=True,
+            capture_stderr=True,
+            verify_command=True,
+        )
+        try:
+            p.Wait()
+            header, separator, output = p.stdout.partition("\n")
+            if not separator:
+                raise ValueError("missing cat-file header")
+            if header.endswith(" missing") or header.endswith(" ambiguous"):
+                raise GitError(f"commit {reference} not found")
+
+            parts = header.split(" ", 2)
+            if len(parts) != 3 or parts[1] != "commit":
+                raise ValueError(
+                    f"unexpected object type {parts[1]!r}"
+                    if len(parts) >= 2
+                    else "invalid header"
+                )
+            sha1, _object_type, _size = parts
+
+            if not output.endswith("\n"):
+                raise ValueError("truncated cat-file object")
+
+            commit = output[:-1]
+        except (GitError, ValueError) as e:
+            logger.error(
+                "error: Failed to resolve or read commit %s", reference
+            )
+            if isinstance(e, GitError):
+                raise
+            raise GitError(str(e)) from e
+
+        return sha1, commit
+
     def _IsChangeId(self, line):
         return CHANGE_ID_RE.match(line)
 

subcmds/download.py

@@ -195,7 +195,7 @@ If no project is specified try to use current directory as a project.
                 elif opt.revert:
                     project._Revert(dl.commit)
                 elif opt.ffonly:
-                    project._FastForward(dl.commit, ffonly=True)
+                    project._FastForward(dl.commit)
                 else:
                     if opt.branch:
                         project.StartBranch(opt.branch, revision=dl.commit)

subcmds/forall.py

@@ -244,10 +244,14 @@ without iterating through the remaining projects.
         mirror = self.manifest.IsMirror
 
         if opt.regex:
-            projects = self.FindProjects(args, all_manifests=all_trees)
+            projects = self.FindProjects(
+                args,
+                groups=opt.groups,
+                all_manifests=all_trees,
+            )
         elif opt.inverse_regex:
             projects = self.FindProjects(
-                args, inverse=True, all_manifests=all_trees
+                args, inverse=True, groups=opt.groups, all_manifests=all_trees
             )
         else:
             projects = self.GetProjects(

subcmds/info.py

@@ -18,7 +18,7 @@ import io
 import json
 import optparse
 import sys
-from typing import Any, Dict, List, NamedTuple
+from typing import Any, Dict, List, NamedTuple, Optional, Tuple
 
 from color import Coloring
 from command import DEFAULT_LOCAL_JOBS
@@ -189,18 +189,26 @@ class Info(PagedCommand):
             "superproject_revision": srev,
         }
 
+    @staticmethod
+    def _GetCurrentBranch(branches: Dict[str, Any]) -> Optional[str]:
+        """Return the name of the current branch from a GetBranches mapping."""
+        return next(
+            (name for name, branch in branches.items() if branch.current), None
+        )
+
     @classmethod
     def _getProjectData(cls, project) -> Dict[str, Any]:
         """Gather project data as a dict."""
+        branches = project.GetBranches()
+        currentBranch = cls._GetCurrentBranch(branches)
         data = {
             "name": project.name,
             "mount_path": project.worktree,
             "current_revision": project.GetHeadRevisionId()
             or project.GetRevisionId(),
             "manifest_revision": project.revisionExpr,
-            "local_branches": list(project.GetBranches()),
+            "local_branches": list(branches),
         }
-        currentBranch = project.CurrentBranch
         if currentBranch:
             data["current_branch"] = currentBranch
         return data
@@ -285,6 +293,9 @@ class Info(PagedCommand):
         text = out.nofmt_printer("text")
         dimtext = out.printer("dimtext", attr="dim")
 
+        branches = project.GetBranches()
+        currentBranch = cls._GetCurrentBranch(branches)
+
         heading("Project: ")
         headtext(project.name)
         out.nl()
@@ -297,7 +308,6 @@ class Info(PagedCommand):
         headtext(project.GetHeadRevisionId() or project.GetRevisionId())
         out.nl()
 
-        currentBranch = project.CurrentBranch
         if currentBranch:
             heading("Current branch: ")
             headtext(currentBranch)
@@ -307,7 +317,7 @@ class Info(PagedCommand):
         headtext(project.revisionExpr)
         out.nl()
 
-        localBranches = list(project.GetBranches().keys())
+        localBranches = list(branches)
         heading("Local Branches: ")
         redtext(str(len(localBranches)))
         if localBranches:
@@ -327,25 +337,10 @@ class Info(PagedCommand):
                 branch = branch[len(R_HEADS) :]
             logTarget = R_M + branch
 
-            bareTmp = project.bare_git._bare
+            localCommits, originCommits = cls._GetDiffCommits(
-            project.bare_git._bare = False
+                project, logTarget
-            localCommits = project.bare_git.rev_list(
-                "--abbrev=8",
-                "--abbrev-commit",
-                "--pretty=oneline",
-                logTarget + "..",
-                "--",
             )
 
-            originCommits = project.bare_git.rev_list(
-                "--abbrev=8",
-                "--abbrev-commit",
-                "--pretty=oneline",
-                ".." + logTarget,
-                "--",
-            )
-            project.bare_git._bare = bareTmp
-
             heading("Local Commits: ")
             redtext(str(len(localCommits)))
             dimtext(" (on current branch)")
@@ -375,6 +370,35 @@ class Info(PagedCommand):
 
         return buf.getvalue()
 
+    @classmethod
+    def _GetDiffCommits(
+        cls, project: Any, log_target: str
+    ) -> Tuple[List[str], List[str]]:
+        """Return local-only and remote-only commits from one history walk."""
+        git = getattr(project, "work_git", None) or getattr(
+            project, "bare_git", None
+        )
+        if git is None:
+            return [], []
+        commits = git.rev_list(
+            "--left-right",
+            "--abbrev=8",
+            "--abbrev-commit",
+            "--pretty=oneline",
+            f"HEAD...{log_target}",
+            "--",
+        )
+        if isinstance(commits, str):
+            commits = commits.splitlines()
+        local = []
+        remote = []
+        for commit in commits:
+            if commit.startswith("<"):
+                local.append(commit[1:])
+            elif commit.startswith(">"):
+                remote.append(commit[1:])
+        return local, remote
+
     def _printDiffInfo(self, opt, args):
         projs = self.GetProjects(args, all_manifests=not opt.this_manifest_only)
 
@@ -404,10 +428,18 @@ class Info(PagedCommand):
         project = cls.get_parallel_context()["projects"][project_idx]
 
         branches = []
-        br = [project.GetUploadableBranch(x) for x in project.GetBranches()]
+        local_branches = project.GetBranches()
-        br = [x for x in br if x]
+        current_branch = cls._GetCurrentBranch(local_branches)
         if opt.current_branch:
-            br = [x for x in br if x.name == project.CurrentBranch]
+            candidate_branches = (
+                [current_branch]
+                if current_branch and current_branch in local_branches
+                else []
+            )
+        else:
+            candidate_branches = local_branches
+        br = [project.GetUploadableBranch(x) for x in candidate_branches]
+        br = [x for x in br if x]
 
         for b in br:
             branches.append(
@@ -416,7 +448,7 @@ class Info(PagedCommand):
                     name=b.name,
                     commits=b.commits,
                     date=b.date,
-                    is_current=b.name == project.CurrentBranch,
+                    is_current=b.name == current_branch,
                 )
             )
         return branches

subcmds/list.py

@@ -109,7 +109,10 @@ This is similar to running: repo forall -c 'echo "$REPO_PATH : $REPO_PROJECT"'.
             )
         else:
             projects = self.FindProjects(
-                args, all_manifests=not opt.this_manifest_only
+                args,
+                groups=opt.groups,
+                missing_ok=opt.all,
+                all_manifests=not opt.this_manifest_only,
             )
 
         def _getpath(x):

subcmds/overview.py

@@ -59,10 +59,15 @@ are displayed.
         for project in self.GetProjects(
             args, all_manifests=not opt.this_manifest_only
         ):
-            br = [project.GetUploadableBranch(x) for x in project.GetBranches()]
+            local_branches = project.GetBranches()
-            br = [x for x in br if x]
+            br = []
+            for name, branch in local_branches.items():
+                uploadable = project.GetUploadableBranch(name)
+                if uploadable:
+                    uploadable.branch.current = branch.current
+                    br.append(uploadable)
             if opt.current_branch:
-                br = [x for x in br if x.name == project.CurrentBranch]
+                br = [x for x in br if x.current]
             all_branches.extend(br)
 
         if not all_branches:
@@ -97,7 +102,7 @@ are displayed.
             print(
                 "%s %-33s (%2d commit%s, %s)"
                 % (
-                    branch.name == project.CurrentBranch and "*" or " ",
+                    branch.current and "*" or " ",
                     branch.name,
                     len(commits),
                     len(commits) != 1 and "s" or " ",

subcmds/prune.py

@@ -80,7 +80,7 @@ class Prune(PagedCommand):
             print(
                 "%s %-33s "
                 % (
-                    branch.name == project.CurrentBranch and "*" or " ",
+                    branch.current and "*" or " ",
                     branch.name,
                 ),
                 end="",

subcmds/rebase.py

@@ -139,6 +139,8 @@ branch but need to incorporate new upstream changes "underneath" them.
             common_args.append("--autosquash")
         if opt.interactive:
             common_args.append("-i")
+        if opt.auto_stash:
+            common_args.append("--autostash")
 
         config = self.manifest.manifestProject.config
         out = RebaseColoring(config)
@@ -188,29 +190,10 @@ branch but need to incorporate new upstream changes "underneath" them.
             out.nl()
             out.flush()
 
-            needs_stash = False
-            if opt.auto_stash:
-                stash_args = ["update-index", "--refresh", "-q"]
-
-                if GitCommand(project, stash_args).Wait() != 0:
-                    needs_stash = True
-                    # Dirty index, requires stash...
-                    stash_args = ["stash"]
-
-                    if GitCommand(project, stash_args).Wait() != 0:
-                        ret += 1
-                        continue
-
             if GitCommand(project, args).Wait() != 0:
                 ret += 1
                 continue
 
-            if needs_stash:
-                stash_args.append("pop")
-                stash_args.append("--quiet")
-                if GitCommand(project, stash_args).Wait() != 0:
-                    ret += 1
-
         if ret:
             msg_fmt = "%d projects had errors"
             self.git_event_log.ErrorEvent(msg_fmt % (ret), msg_fmt)

subcmds/start.py

@@ -18,7 +18,7 @@ from typing import NamedTuple
 from command import Command
 from command import DEFAULT_LOCAL_JOBS
 from error import RepoExitError
-from git_command import git
+from git_command import IsValidBranchName
 from git_config import IsImmutable
 from progress import Progress
 from repo_logging import RepoLogger
@@ -75,7 +75,7 @@ revision specified in the manifest.
             self.Usage()
 
         nb = args[0]
-        if not git.check_ref_format("heads/%s" % nb):
+        if not IsValidBranchName(nb):
             self.OptionParser.error("'%s' is not a valid name" % nb)
 
     @classmethod

subcmds/sync.py

@@ -28,7 +28,7 @@ import subprocess
 import sys
 import tempfile
 import time
-from typing import List, NamedTuple, Optional, Set, Tuple, Union
+from typing import Dict, List, NamedTuple, Optional, Set, Tuple, Union
 import urllib.error
 import urllib.parse
 import urllib.request
@@ -72,6 +72,7 @@ from git_refs import HEAD
 from git_refs import R_HEADS
 import git_superproject
 from hooks import RepoHook
+from manifest_xml import XmlManifest
 import platform_utils
 from progress import elapsed_str
 from progress import jobs_str
@@ -156,6 +157,88 @@ def _SafeCheckoutOrder(checkouts: List[Project]) -> List[List[Project]]:
     return res
 
 
+def _NestedProjects(projects: List[Project]) -> List[Project]:
+    """Return the projects in |projects| living inside another one's path."""
+    return [p for level in _SafeCheckoutOrder(projects)[1:] for p in level]
+
+
+def _ParentFirstBatches(projects: List[Project]) -> List[List[Project]]:
+    """Group |projects| so that a parent is fetched before its submodules.
+
+    A discovered submodule can only be fetched at the right revision once the
+    project holding its gitlink has been fetched, so it is held back to a later
+    batch than its parent. Projects that are not discovered submodules all end
+    up in the first batch, which keeps manifests without submodules on a single
+    batch.
+    """
+    batches = collections.defaultdict(list)
+    for project in projects:
+        depth = 0
+        ancestor = project
+        while ancestor.Derived and ancestor.parent:
+            depth += 1
+            ancestor = ancestor.parent
+        batches[depth].append(project)
+    return [batches[depth] for depth in sorted(batches)]
+
+
+def _RefreshDerivedRevisions(
+    projects: List[Project],
+    submodule_revisions: Optional[Dict[Project, Dict[str, str]]] = None,
+) -> List[Project]:
+    """Re-resolve the gitlinks of the discovered submodules in |projects|.
+
+    The revision of a discovered submodule is read from its parent when the
+    manifest is loaded, so it is stale as soon as the parent gets fetched. It
+    has to be resolved again once the parent is up-to-date, and before the
+    submodule itself is fetched and checked out.
+
+    Args:
+        projects: The projects whose discovered submodules to resolve.
+        submodule_revisions: Gitlinks already read, keyed by the project
+            holding them. Passing the same dict for project sets that follow
+            the same fetches, e.g. the levels of one checkout order, keeps a
+            project from being read more than once.
+
+    Returns:
+        The submodules that their parent no longer holds a gitlink for.
+    """
+    if submodule_revisions is None:
+        submodule_revisions = {}
+
+    subprojects_by_parent = collections.defaultdict(list)
+    for project in projects:
+        if project.Derived and project.parent:
+            subprojects_by_parent[project.parent].append(project)
+
+    removed = []
+    for parent, subprojects in subprojects_by_parent.items():
+        revisions = submodule_revisions.get(parent)
+        if revisions is None:
+            revisions = parent.GetSubmoduleRevisions()
+            if revisions is None:
+                # Leave the submodules of a parent we cannot read alone.
+                continue
+            submodule_revisions[parent] = revisions
+        for subproject in subprojects:
+            rev = revisions.get(subproject.gitlink_path)
+            if rev:
+                subproject.SetRevision(rev, revisionId=rev)
+            else:
+                removed.append(subproject)
+    return removed
+
+
+def _WithoutProjects(
+    projects: List[Project], unwanted: List[Project]
+) -> List[Project]:
+    """Return |projects| without the projects in |unwanted|."""
+    if not unwanted:
+        return projects
+    dropped = set(unwanted)
+    return [p for p in projects if p not in dropped]
+
+
 def _chunksize(projects: int, jobs: int) -> int:
     """Calculate chunk size for the given number of projects and jobs."""
     return min(max(1, projects // jobs), WORKER_BATCH_SIZE)
@@ -224,7 +307,8 @@ class _SyncResult(NamedTuple):
 
     Attributes:
       project_index (int): The index of the project in the shared list.
-      relpath (str): The project's relative path from the repo client top.
+      relpath (str): The project's path relative to the tree being synced.
+          Unlike Project.relpath, it is unique across submanifests.
       remote_fetched (bool): True if the remote was actually queried.
       fetch_success (bool): True if the fetch operation was successful.
       fetch_errors (List[Exception]): The Exceptions from a failed fetch.
@@ -450,6 +534,8 @@ later is required to fix a server side protocol bug.
             help="number of network jobs to run in parallel (defaults to "
             "--jobs or 1). Ignored unless --no-interleaved is set",
         )
+
+        jobs_checkout_default = self._GetHelpForCpuJobCount(DEFAULT_LOCAL_JOBS)
         p.add_option(
             "--jobs-checkout",
             default=None,
@@ -457,7 +543,7 @@ later is required to fix a server side protocol bug.
             metavar="JOBS",
             help=(
                 "number of local checkout jobs to run in parallel (defaults "
-                f"to --jobs or {DEFAULT_LOCAL_JOBS}). Ignored unless "
+                f"to --jobs or {jobs_checkout_default}). Ignored unless "
                 "--no-interleaved is set"
             ),
         )
@@ -1067,6 +1153,40 @@ later is required to fix a server side protocol bug.
 
         return _FetchResult(ret, fetched)
 
+    def _FetchParentFirst(
+        self,
+        projects: List[Project],
+        opt: optparse.Values,
+        err_event: _threading.Event,
+        ssh_proxy: ssh.ProxyManager,
+        errors: List[Exception],
+    ) -> _FetchResult:
+        """Fetch |projects|, holding submodules back until their parent is done.
+
+        Args:
+            projects: Projects to fetch.
+            opt: Program options returned from optparse. See _Options().
+            err_event: Whether an error was hit while processing.
+            ssh_proxy: SSH manager for clients & masters.
+            errors: A list to accumulate errors.
+
+        Returns:
+            _FetchResult for all the batches combined.
+        """
+        success = True
+        fetched = set()
+        for batch in _ParentFirstBatches(projects):
+            batch = _WithoutProjects(batch, _RefreshDerivedRevisions(batch))
+            if not batch:
+                continue
+            batch.sort(key=self._fetch_times.Get, reverse=True)
+            result = self._Fetch(batch, opt, err_event, ssh_proxy, errors)
+            success = success and result.success
+            fetched.update(result.projects)
+            if not success and opt.fail_fast:
+                break
+        return _FetchResult(success, fetched)
+
     def _FetchMain(
         self, opt, args, all_projects, err_event, ssh_proxy, manifest, errors
     ):
@@ -1083,12 +1203,10 @@ later is required to fix a server side protocol bug.
         Returns:
             List of all projects that should be checked out.
         """
-        to_fetch = []
-        to_fetch.extend(all_projects)
-        to_fetch.sort(key=self._fetch_times.Get, reverse=True)
-
         try:
-            result = self._Fetch(to_fetch, opt, err_event, ssh_proxy, errors)
+            result = self._FetchParentFirst(
+                all_projects, opt, err_event, ssh_proxy, errors
+            )
             success = result.success
             fetched = result.projects
             if not success:
@@ -1131,7 +1249,9 @@ later is required to fix a server side protocol bug.
                 if previously_missing_set == missing_set:
                     break
                 previously_missing_set = missing_set
-                result = self._Fetch(missing, opt, err_event, ssh_proxy, errors)
+                result = self._FetchParentFirst(
+                    missing, opt, err_event, ssh_proxy, errors
+                )
                 success = result.success
                 new_fetched = result.projects
                 if not success:
@@ -1494,10 +1614,23 @@ later is required to fix a server side protocol bug.
         # Only check dirty or locally modified projects. These can't be
         # freshly cloned and will accumulate garbage.
         try:
-            is_dirty = project.IsDirty(consider_untracked=True)
+            status = project._GetStatusSnapshot(
+                untracked_files="normal", branch=True
+            )
+            if status is not None:
+                is_dirty = status.is_dirty(consider_untracked=True)
+                head_rev = status.branch_oid
+            else:
+                is_dirty = project.IsDirty(consider_untracked=True)
+                head_rev = project.work_git.rev_parse(HEAD)
+
+            if head_rev is None:
+                # Porcelain v2 reports an unborn branch as "(initial)".  The
+                # legacy rev-parse path failed here and skipped the bloat
+                # calculation, so preserve that behavior.
+                return None
 
             manifest_rev = project.GetRevisionId(project.bare_ref.all)
-            head_rev = project.work_git.rev_parse(HEAD)
             has_local_commits = manifest_rev != head_rev
 
             if not (is_dirty or has_local_commits):
@@ -2366,6 +2499,7 @@ later is required to fix a server side protocol bug.
             manifest=manifest,
             all_manifests=not opt.this_manifest_only,
         )
+        self._CheckReprojectCmdNesting(opt, args, manifest, all_projects)
 
         # Log the repo projects by existing and new.
         existing = [x for x in all_projects if x.Exists]
@@ -2429,6 +2563,46 @@ later is required to fix a server side protocol bug.
         if not opt.quiet:
             print("repo sync has finished successfully.")
 
+    def _CheckReprojectCmdNesting(
+        self,
+        opt: optparse.Values,
+        args: List[str],
+        manifest: XmlManifest,
+        all_projects: List[Project],
+    ) -> None:
+        """Fail when repo.reprojectcmd is used on a manifest nesting projects.
+
+        The command materializes a project's tree without Git, so nothing
+        keeps it from clobbering a project or submodule checked out inside
+        that tree. See docs/reproject-cmd.md.
+        """
+        if not any(p.UseReprojectCmd for p in all_projects):
+            return
+        projects = all_projects
+        if args:
+            # Nesting is a property of the manifest, not of the projects
+            # picked on the command line.
+            projects = self.GetProjects(
+                [],
+                groups=opt.groups,
+                missing_ok=True,
+                submodules_ok=opt.recurse_submodules,
+                manifest=manifest,
+                all_manifests=not opt.this_manifest_only,
+            )
+        nested = _NestedProjects(projects)
+        if not nested:
+            return
+        e = SyncError(
+            "error: repo.reprojectcmd does not support nested projects or "
+            "submodules; found:\n"
+            + "\n".join(
+                f" - {p.RelPath(local=opt.this_manifest_only)}" for p in nested
+            )
+        )
+        logger.error(e)
+        raise e
+
     def _CreateSyncProgressThread(
         self, pm: Progress, stop_event: _threading.Event
     ) -> _threading.Thread:
@@ -2758,7 +2932,7 @@ later is required to fix a server side protocol bug.
 
         return _SyncResult(
             project_index=project_index,
-            relpath=project.relpath,
+            relpath=project.RelPath(local=opt.this_manifest_only),
             fetch_success=fetch_success,
             remote_fetched=remote_fetched,
             checkout_success=checkout_success,
@@ -2906,6 +3080,10 @@ later is required to fix a server side protocol bug.
         self._interleaved_err_checkout = False
         self._interleaved_err_checkout_results = []
 
+        # Project.relpath is relative to its own (sub)manifest, so it does not
+        # tell apart projects of different manifests being synced together.
+        _RelPath = lambda p: p.RelPath(local=opt.this_manifest_only)
+
         err_event = multiprocessing.Event()
         finished_relpaths = set()
         project_list = list(all_projects)
@@ -2942,13 +3120,13 @@ later is required to fix a server side protocol bug.
                             projects_to_sync = [
                                 p
                                 for p in project_list
-                                if p.relpath not in finished_relpaths
+                                if _RelPath(p) not in finished_relpaths
                             ]
                             if not projects_to_sync:
                                 break
 
                             pending_relpaths = {
-                                p.relpath for p in projects_to_sync
+                                _RelPath(p) for p in projects_to_sync
                             }
                             if previously_pending_relpaths == pending_relpaths:
                                 stalled_projects_str = "\n".join(
@@ -2977,12 +3155,22 @@ later is required to fix a server side protocol bug.
                             # projects in one level can be processed in
                             # parallel, but we must wait for a level to complete
                             # before starting the next.
+                            submodule_revisions = {}
                             for level_projects in _SafeCheckoutOrder(
                                 projects_to_sync
                             ):
                                 if not level_projects:
                                     continue
 
+                                level_projects = _WithoutProjects(
+                                    level_projects,
+                                    _RefreshDerivedRevisions(
+                                        level_projects, submodule_revisions
+                                    ),
+                                )
+                                if not level_projects:
+                                    continue
+
                                 objdir_project_map = collections.defaultdict(
                                     list
                                 )

subcmds/upload.py

@@ -25,7 +25,6 @@ from editor import Editor
 from error import GitError
 from error import SilentRepoExitError
 from error import UploadError
-from git_command import GitCommand
 from git_refs import R_HEADS
 import git_superproject
 from hooks import RepoHook
@@ -379,7 +378,7 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
             default=True,
             help="disable verifying ssl certs (unsafe)",
         )
-        RepoHook.AddOptionGroup(p, "pre-upload")
+        RepoHook.AddOptionGroup(p, "pre-upload", allow_fix=True)
 
     def _SingleBranch(self, opt, branch, people):
         project = branch.project
@@ -436,6 +435,18 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
         self._UploadAndReport(opt, [branch], people)
 
     def _MultipleBranches(self, opt, pending, people):
+        if opt.yes and (opt.current_branch or opt.branch):
+            todo = [
+                branch
+                for _, avail in pending
+                for branch in avail
+                if branch is not None
+            ]
+            if not todo:
+                _die("nothing ready for upload")
+            self._UploadAndReport(opt, todo, people)
+            return
+
         projects = {}
         branches = {}
 
@@ -649,6 +660,7 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
             validate_certs=opt.validate_certs,
             push_options=push_options,
             patchset_description=opt.patchset_description,
+            git_event_log=self.git_event_log,
         )
 
         branch.uploaded = True
@@ -704,36 +716,31 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
             raise UploadExitError(aggregate_errors=aggregate_errors)
 
     def _GetMergeBranch(self, project, local_branch=None):
+        """Get the merge branch name for a local branch.
+
+        Resolves the merge branch in-memory via project configuration to
+        avoid git subprocess overhead during upload.
+        """
         if local_branch is None:
-            p = GitCommand(
+            local_branch = project.CurrentBranch
-                project,
+        if local_branch:
-                ["rev-parse", "--abbrev-ref", "HEAD"],
+            branch = project.GetBranch(local_branch)
-                capture_stdout=True,
+            if branch.merge:
-                capture_stderr=True,
+                return branch.merge
-            )
+        return ""
-            p.Wait()
-            local_branch = p.stdout.strip()
-        p = GitCommand(
-            project,
-            ["config", "--get", "branch.%s.merge" % local_branch],
-            capture_stdout=True,
-            capture_stderr=True,
-        )
-        p.Wait()
-        merge_branch = p.stdout.strip()
-        return merge_branch
 
     @classmethod
     def _GatherOne(cls, opt, project_idx):
         """Figure out the upload status for |project|."""
         project = cls.get_parallel_context()["projects"][project_idx]
+        cbr = None
         if opt.current_branch:
             cbr = project.CurrentBranch
             up_branch = project.GetUploadableBranch(cbr)
             avail = [up_branch] if up_branch else None
         else:
             avail = project.GetUploadableBranches(opt.branch)
-        return (project_idx, avail)
+        return (project_idx, avail, cbr)
 
     def Execute(self, opt, args):
         projects = self.GetProjects(
@@ -743,7 +750,7 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
         def _ProcessResults(_pool, _out, results):
             pending = []
             for result in results:
-                project_idx, avail = result
+                project_idx, avail, current_branch = result
                 project = projects[project_idx]
                 if avail is None:
                     logger.error(
@@ -751,7 +758,7 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
                         "You might be able to fix the branch by running:\n"
                         "  git branch --set-upstream-to m/%s",
                         project.RelPath(local=opt.this_manifest_only),
-                        project.CurrentBranch,
+                        current_branch,
                         project.manifest.branch,
                     )
                 elif avail:

subcmds/version.py

@@ -14,10 +14,12 @@
 
 import platform
 import sys
+from typing import Any, Tuple
 
 from command import Command
 from command import MirrorSafeCommand
 from git_command import git
+from git_command import git_require
 from git_command import RepoSourceVersion
 from git_command import user_agent
 from git_refs import HEAD
@@ -34,6 +36,22 @@ class Version(Command, MirrorSafeCommand):
 %prog
 """
 
+    @staticmethod
+    def _RepoVersion(project: Any) -> Tuple[str, str]:
+        """Return repo's describe string and commit date."""
+        if git_require((2, 32, 0)):
+            output = project.bare_git.log(
+                "-1", "--format=%(describe)%n%cD", HEAD
+            )
+            description, commit_date = output.rstrip("\n").split("\n", 1)
+            if description:
+                return description, commit_date
+
+        return (
+            project.bare_git.describe(HEAD),
+            project.bare_git.log("-1", "--format=%cD", HEAD),
+        )
+
     def Execute(self, opt, args):
         rp = self.manifest.repoProject
         rem = rp.GetRemote()
@@ -41,11 +59,11 @@ class Version(Command, MirrorSafeCommand):
 
         # These might not be the same.  Report them both.
         src_ver = RepoSourceVersion()
-        rp_ver = rp.bare_git.describe(HEAD)
+        rp_ver, commit_date = self._RepoVersion(rp)
         print(f"repo version {rp_ver}")
         print(f"       (from {rem.url})")
         print(f"       (tracking {branch.merge})")
-        print(f"       ({rp.bare_git.log('-1', '--format=%cD', HEAD)})")
+        print(f"       ({commit_date})")
 
         if self.wrapper_path is not None:
             print(f"repo launcher version {self.wrapper_version}")

tests/test_command.py

@@ -14,6 +14,8 @@
 
 """Unittests for the command.py module."""
 
+from typing import Iterable, List, Optional
+
 import pytest
 
 from command import Command
@@ -30,12 +32,15 @@ class FakeProject:
         gitdir=None,
         derived_subprojects=None,
         sync_s=False,
+        exists: bool = True,
     ):
         self.name = name
         self.relpath = relpath
+        self.worktree = f"/work/{relpath}"
+        self.manifest = None
         self.gitdir = gitdir or f"/git/{relpath}"
         self.sync_s = sync_s
-        self.Exists = True
+        self.Exists = exists
         self._derived_subprojects = derived_subprojects or []
 
     def GetDerivedSubprojects(self):
@@ -51,11 +56,59 @@ class FakeProject:
 class FakeManifest:
     """Minimal manifest double for Command.GetProjects tests."""
 
-    def __init__(self, projects):
+    def __init__(
-        self.projects = projects
+        self,
+        projects: Iterable[FakeProject],
+        *,
+        all_projects: Optional[Iterable[FakeProject]] = None,
+        effective_groups: str = "default",
+    ):
+        self.projects = list(projects)
+        self.all_projects = (
+            list(self.projects) if all_projects is None else list(all_projects)
+        )
+        self._effective_groups = effective_groups
+        self.path_prefix = ""
+
+        # all_projects may include projects owned by child manifests,
+        # so only set this manifest on its direct projects.
+        for project in self.projects:
+            self._set_project_manifest(project)
+
+    def _set_project_manifest(self, project: FakeProject) -> None:
+        project.manifest = self
+        for subproject in project.GetDerivedSubprojects():
+            self._set_project_manifest(subproject)
 
     def GetManifestGroupsStr(self):
-        return "default"
+        return self._effective_groups
+
+    def GetProjectsWithName(
+        self, name: str, all_manifests: bool = False
+    ) -> List[FakeProject]:
+        projects = self.all_projects if all_manifests else self.projects
+        return [project for project in projects if project.name == name]
+
+
+class GroupMatchingFakeProject(FakeProject):
+    """Fake project with predictable group matches for GetProjects tests.
+
+    This lets the tests check which groups GetProjects uses without
+    reimplementing Project.MatchesGroups.
+    """
+
+    def __init__(
+        self,
+        name: str,
+        relpath: str,
+        *,
+        matching_groups: Iterable[str],
+    ):
+        super().__init__(name, relpath)
+        self._matching_groups = set(matching_groups)
+
+    def MatchesGroups(self, groups: Iterable[str]) -> bool:
+        return bool(self._matching_groups.intersection(groups))
 
 
 def test_get_projects_keeps_derived_subprojects_for_repeated_repo():
@@ -117,3 +170,180 @@ def test_get_projects_submodule_override(
     projects = cmd.GetProjects([], submodules_ok=submodules_ok)
 
     assert (submodule in projects) is includes_submodule
+
+
+@pytest.mark.parametrize(
+    ("groups", "expected_relpaths"),
+    [
+        (None, ["outer", "sub/child"]),
+        ("", ["outer", "sub/child"]),
+        ("override-group", ["sub/override"]),
+    ],
+    ids=("groups-omitted", "groups-empty", "explicit-override"),
+)
+def test_get_projects_uses_groups_from_each_manifest_unless_overridden(
+    groups: Optional[str],
+    expected_relpaths: List[str],
+) -> None:
+    """Use each manifest's effective groups unless the caller overrides them."""
+    outer_project = GroupMatchingFakeProject(
+        "outer",
+        "outer",
+        matching_groups={"outer-group"},
+    )
+
+    # Both child projects also match "outer". Reusing the outer manifest's
+    # groups would therefore select both child projects.
+    child_project = GroupMatchingFakeProject(
+        "child",
+        "sub/child",
+        matching_groups={"outer-group", "child-group"},
+    )
+    override_project = GroupMatchingFakeProject(
+        "override",
+        "sub/override",
+        matching_groups={"outer-group", "override-group"},
+    )
+
+    child_manifest = FakeManifest(
+        [child_project, override_project],
+        effective_groups="child-group",
+    )
+    outer_manifest = FakeManifest(
+        [outer_project],
+        all_projects=[outer_project, *child_manifest.projects],
+        effective_groups="outer-group",
+    )
+    cmd = Command(manifest=outer_manifest)
+
+    projects = cmd.GetProjects(
+        [],
+        manifest=outer_manifest,
+        groups=groups,
+        all_manifests=True,
+    )
+
+    assert [project.relpath for project in projects] == expected_relpaths
+
+
+def test_get_projects_by_name_uses_groups_from_each_manifest() -> None:
+    """Name matches use the groups from each project's owning manifest."""
+    outer_project = GroupMatchingFakeProject(
+        "shared",
+        "outer/shared",
+        matching_groups={"outer-group"},
+    )
+    child_project = GroupMatchingFakeProject(
+        "shared",
+        "sub/shared",
+        matching_groups={"child-group"},
+    )
+
+    child_manifest = FakeManifest(
+        [child_project],
+        effective_groups="child-group",
+    )
+    outer_manifest = FakeManifest(
+        [outer_project],
+        all_projects=[outer_project, *child_manifest.projects],
+        effective_groups="outer-group",
+    )
+    cmd = Command(manifest=outer_manifest)
+
+    projects = cmd.GetProjects(
+        ["shared"],
+        manifest=outer_manifest,
+        all_manifests=True,
+    )
+
+    assert [project.relpath for project in projects] == [
+        "outer/shared",
+        "sub/shared",
+    ]
+
+
+def test_find_projects_uses_groups_from_each_manifest() -> None:
+    """Use each manifest's effective groups for regex selection."""
+    outer_project = GroupMatchingFakeProject(
+        "match-outer",
+        "outer",
+        matching_groups={"outer-group"},
+    )
+    child_project = GroupMatchingFakeProject(
+        "match-child",
+        "sub/child",
+        matching_groups={"child-group"},
+    )
+    excluded_project = GroupMatchingFakeProject(
+        "match-excluded",
+        "sub/excluded",
+        matching_groups={"other-group"},
+    )
+
+    child_manifest = FakeManifest(
+        [child_project, excluded_project],
+        effective_groups="child-group",
+    )
+    child_manifest.path_prefix = "sub"
+
+    outer_manifest = FakeManifest(
+        [outer_project],
+        all_projects=[
+            outer_project,
+            *child_manifest.projects,
+        ],
+        effective_groups="outer-group",
+    )
+    outer_manifest.outer_client = outer_manifest
+
+    cmd = Command(manifest=outer_manifest)
+
+    projects = cmd.FindProjects(["match"], all_manifests=True)
+
+    assert [project.relpath for project in projects] == [
+        "outer",
+        "sub/child",
+    ]
+
+
+def test_find_projects_uses_explicit_groups() -> None:
+    """Use explicit groups for regex selection."""
+    default_project = GroupMatchingFakeProject(
+        "default",
+        "default",
+        matching_groups={"default-group"},
+    )
+    override_project = GroupMatchingFakeProject(
+        "override",
+        "override",
+        matching_groups={"override-group"},
+    )
+    manifest = FakeManifest(
+        [default_project, override_project],
+        effective_groups="default-group",
+    )
+    cmd = Command(manifest=manifest)
+
+    projects = cmd.FindProjects(
+        ["override"],
+        groups="override-group",
+    )
+
+    assert projects == [override_project]
+
+
+def test_find_projects_allows_missing_projects() -> None:
+    """Allow regex selection to include projects without a checkout."""
+    project = FakeProject(
+        "missing",
+        "missing",
+        exists=False,
+    )
+    cmd = Command(manifest=FakeManifest([project]))
+
+    projects = cmd.FindProjects(
+        ["missing"],
+        missing_ok=True,
+    )
+
+    assert projects == [project]

tests/test_git_command.py

@@ -123,6 +123,7 @@ class GitCommandStreamLogsTest(unittest.TestCase):
     """Tests the GitCommand class stderr log streaming cases."""
 
     def setUp(self):
+        _ = git_command.user_agent.git
         self.mock_process = mock.MagicMock()
         self.mock_process.communicate.return_value = (None, None)
         self.mock_process.wait.return_value = 0
@@ -228,9 +229,162 @@ class GitCommandStreamLogsTest(unittest.TestCase):
         self.assertEqual(cmd.stderr, logs)
 
 
+class GitCommandCaptureBytesTest(unittest.TestCase):
+    """Tests the GitCommand class byte capture cases."""
+
+    def setUp(self) -> None:
+        _ = git_command.user_agent.git
+        self.mock_process = mock.MagicMock()
+        self.mock_process.communicate.return_value = (None, None)
+        self.mock_process.wait.return_value = 0
+
+        self.mock_popen = mock.MagicMock()
+        self.mock_popen.return_value = self.mock_process
+        mock.patch("subprocess.Popen", self.mock_popen).start()
+
+    def tearDown(self) -> None:
+        mock.patch.stopall()
+
+    def test_captures_stdout_as_bytes(self) -> None:
+        self.mock_process.communicate.return_value = (b"\xff\x00", b"error\r\n")
+
+        cmd = git_command.GitCommand(
+            None,
+            ["status"],
+            capture_stdout=True,
+            capture_stdout_bytes=True,
+            capture_stderr=True,
+        )
+
+        self.mock_popen.assert_called_once_with(
+            ["git", "status"],
+            cwd=None,
+            env=mock.ANY,
+            stdin=None,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+        self.assertEqual(cmd.stdout, b"\xff\x00")
+        self.assertEqual(cmd.stderr, "error\n")
+
+    def test_capture_stdout_bytes_auto_enables_capture_stdout(self) -> None:
+        self.mock_process.communicate.return_value = (b"output", b"")
+
+        cmd = git_command.GitCommand(
+            None,
+            ["status"],
+            capture_stdout_bytes=True,
+        )
+
+        self.mock_popen.assert_called_once_with(
+            ["git", "status"],
+            cwd=None,
+            env=mock.ANY,
+            stdin=None,
+            stdout=subprocess.PIPE,
+            stderr=None,
+        )
+        self.assertEqual(cmd.stdout, b"output")
+
+    def test_capture_stdout_bytes_with_merge_output_raises(self) -> None:
+        with self.assertRaises(ValueError):
+            git_command.GitCommand(
+                None,
+                ["status"],
+                capture_stdout_bytes=True,
+                merge_output=True,
+            )
+
+    def test_captures_stdout_as_bytes_encodes_str_input(self) -> None:
+        self.mock_process.communicate.return_value = (b"output", b"")
+
+        git_command.GitCommand(
+            None,
+            ["status"],
+            input="hello world",
+            capture_stdout_bytes=True,
+        )
+
+        self.mock_process.communicate.assert_called_once_with(
+            input=b"hello world"
+        )
+
+    def test_captures_stdout_as_bytes_encodes_surrogate_input(self) -> None:
+        self.mock_process.communicate.return_value = (b"output", b"")
+
+        git_command.GitCommand(
+            None,
+            ["status"],
+            input="file_\udcff.txt",
+            capture_stdout_bytes=True,
+        )
+
+        self.mock_process.communicate.assert_called_once_with(
+            input=b"file_\xff.txt"
+        )
+
+    def test_captures_stdout_as_bytes_passes_bytes_input(self) -> None:
+        self.mock_process.communicate.return_value = (b"output", b"")
+
+        git_command.GitCommand(
+            None,
+            ["status"],
+            input=b"raw_\xff.txt",
+            capture_stdout_bytes=True,
+        )
+
+        self.mock_process.communicate.assert_called_once_with(
+            input=b"raw_\xff.txt"
+        )
+
+    def test_verify_command_truncates_nul_delimited_stdout(self) -> None:
+        cmd = git_command.GitCommand(
+            None,
+            ["status"],
+            capture_stdout_bytes=True,
+        )
+        cmd.rc = 1
+        cmd.stdout = b"first_file\0second_file\0third_file"
+        cmd.stderr = "stderr"
+        with self.assertRaises(git_command.GitCommandError) as cm:
+            cmd.VerifyCommand()
+        self.assertEqual(cm.exception.git_stdout, "first_file")
+
+    def test_verify_command_decodes_bytes_stdout(self) -> None:
+        cmd = git_command.GitCommand(
+            None,
+            ["status"],
+            capture_stdout_bytes=True,
+        )
+        cmd.rc = 1
+        cmd.stdout = b"error\xff\nline2"
+        cmd.stderr = "stderr"
+        with self.assertRaises(git_command.GitCommandError) as cm:
+            cmd.VerifyCommand()
+        self.assertEqual(cm.exception.git_stdout, "error\\xff")
+
+
 class GitCallUnitTest(unittest.TestCase):
     """Tests the _GitCall class (via git_command.git)."""
 
+    def test_valid_branch_name_uses_branch_mode(self) -> None:
+        """Branch validation applies Git's branch-specific restrictions."""
+        command = mock.MagicMock()
+        command.Wait.return_value = 1
+        with mock.patch.object(
+            git_command, "GitCommand", return_value=command
+        ) as check:
+            self.assertFalse(git_command.IsValidBranchName("-topic"))
+
+        check.assert_called_once_with(
+            None,
+            ["check-ref-format", "--branch", "-topic"],
+            capture_stdout=True,
+            capture_stderr=True,
+            add_event_log=False,
+            log_as_error=False,
+        )
+
     def test_version_tuple(self):
         """Check git.version_tuple() handling."""
         ver = git_command.git.version_tuple()

tests/test_git_config.py

@@ -256,8 +256,8 @@ def test_remote_save_with_push_url_without_projectname(
         ("0" * 64, True),
         ("f" * 64, True),
         ("a" * 39, False),
-        ("a" * 41, True),
+        ("a" * 41, False),
-        ("a" * 63, True),
+        ("a" * 63, False),
         ("a" * 65, False),
         ("g" * 40, False),
         ("g" * 64, False),

tests/test_git_refs.py

@@ -17,6 +17,8 @@
 import os
 from pathlib import Path
 import subprocess
+from typing import Any, List
+from unittest import mock
 
 import pytest
 import utils_for_test
@@ -24,7 +26,7 @@ import utils_for_test
 import git_refs
 
 
-def _run(repo, *args):
+def _run(repo: str, *args: str) -> str:
     return subprocess.run(
         ["git", "-C", repo, *args],
         stdout=subprocess.PIPE,
@@ -34,7 +36,7 @@ def _run(repo, *args):
     ).stdout.strip()
 
 
-def _init_repo(tmp_path, reftable=False):
+def _init_repo(tmp_path: Path, reftable: bool = False) -> str:
     repo = os.path.join(tmp_path, "repo")
     ref_format = "reftable" if reftable else "files"
     utils_for_test.init_git_tree(repo, ref_format=ref_format)
@@ -57,10 +59,154 @@ def test_reads_refs(tmp_path, reftable):
     branch = _run(repo, "symbolic-ref", "--short", "HEAD")
     head = _run(repo, "rev-parse", "HEAD")
     assert refs.symref("HEAD") == f"refs/heads/{branch}"
+    assert refs.head == f"refs/heads/{branch}"
     assert refs.get("HEAD") == head
     assert refs.get(f"refs/heads/{branch}") == head
 
 
+@pytest.mark.parametrize("reftable", [False, True])
+def test_reads_detached_head(tmp_path: Path, reftable: bool) -> None:
+    if reftable and not utils_for_test.supports_reftable():
+        pytest.skip("reftable not supported")
+
+    repo = _init_repo(tmp_path, reftable=reftable)
+    head = _run(repo, "rev-parse", "HEAD")
+    _run(repo, "checkout", "--detach", head)
+    refs = git_refs.GitRefs(os.path.join(repo, ".git"))
+
+    assert refs.symref("HEAD") == ""
+    assert refs.head == head
+    assert refs.get("HEAD") == head
+
+
+def test_reads_head_with_root_refs_in_one_command(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Git 2.45 and newer include HEAD in the ref snapshot."""
+    head = "1" * 40
+    commands = []
+
+    class FakeGitCommand:
+        def __init__(
+            self, _project: Any, cmdv: List[str], **_kwargs: Any
+        ) -> None:
+            commands.append(cmdv)
+            self.stdout = (
+                f"{head}\0HEAD\0refs/heads/main\n"
+                f"{head}\0refs/heads/main\0\n"
+            )
+
+        def Wait(self) -> int:
+            return 0
+
+    monkeypatch.setattr(git_refs, "GitCommand", FakeGitCommand)
+    monkeypatch.setattr(git_refs, "git_require", lambda _version: True)
+    refs = git_refs.GitRefs("/nonexistent")
+    with mock.patch.object(refs, "_ReadSymbolicRef") as read_head:
+        assert refs.get("HEAD") == head
+
+    assert commands == [
+        [
+            "for-each-ref",
+            "--include-root-refs",
+            "--format=%(objectname)%00%(refname)%00%(symref)",
+            "HEAD",
+            "refs",
+        ]
+    ]
+    read_head.assert_not_called()
+
+
+def test_root_ref_snapshot_falls_back_for_unborn_head(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """An unborn HEAD still uses symbolic-ref after the ref snapshot."""
+
+    class FakeGitCommand:
+        def __init__(
+            self, _project: Any, _cmdv: List[str], **_kwargs: Any
+        ) -> None:
+            self.stdout = ""
+
+        def Wait(self) -> int:
+            return 0
+
+    monkeypatch.setattr(git_refs, "GitCommand", FakeGitCommand)
+    monkeypatch.setattr(git_refs, "git_require", lambda _version: True)
+    refs = git_refs.GitRefs("/nonexistent")
+
+    def read_head(name: str) -> None:
+        assert name == "HEAD"
+        refs._symref[name] = "refs/heads/main"
+
+    monkeypatch.setattr(refs, "_ReadSymbolicRef", read_head)
+
+    assert refs.symref("HEAD") == "refs/heads/main"
+
+
+def test_old_git_keeps_separate_head_fallback(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Git before 2.45 uses the original for-each-ref and HEAD calls."""
+    head = "1" * 40
+    commands = []
+
+    class FakeGitCommand:
+        def __init__(
+            self, _project: Any, cmdv: List[str], **_kwargs: Any
+        ) -> None:
+            commands.append(cmdv)
+            self.stdout = f"{head}\0refs/heads/main\0\n"
+
+        def Wait(self) -> int:
+            return 0
+
+    monkeypatch.setattr(git_refs, "GitCommand", FakeGitCommand)
+    monkeypatch.setattr(git_refs, "git_require", lambda _version: False)
+    refs = git_refs.GitRefs("/nonexistent")
+
+    def read_head(name: str) -> None:
+        assert name == "HEAD"
+        refs._symref[name] = "refs/heads/main"
+
+    monkeypatch.setattr(refs, "_ReadSymbolicRef", read_head)
+
+    assert refs.get("HEAD") == head
+    assert commands == [
+        [
+            "for-each-ref",
+            "--format=%(objectname)%00%(refname)%00%(symref)",
+        ]
+    ]
+
+
+def test_for_each_ref_failure_falls_back_to_symbolic_ref(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """When for-each-ref fails, HEAD is still resolved via symbolic-ref."""
+
+    class FakeGitCommand:
+        def __init__(
+            self, _project: Any, _cmdv: List[str], **_kwargs: Any
+        ) -> None:
+            self.stdout = ""
+
+        def Wait(self) -> int:
+            return 1
+
+    monkeypatch.setattr(git_refs, "GitCommand", FakeGitCommand)
+    monkeypatch.setattr(git_refs, "git_require", lambda _version: True)
+    refs = git_refs.GitRefs("/nonexistent")
+
+    def read_head(name: str) -> None:
+        assert name == "HEAD"
+        refs._symref[name] = "refs/heads/main"
+
+    monkeypatch.setattr(refs, "_ReadSymbolicRef", read_head)
+
+    assert refs.symref("HEAD") == "refs/heads/main"
+
+
 @pytest.mark.parametrize("reftable", [False, True])
 def test_updates_when_refs_change(tmp_path, reftable):
     if reftable and not utils_for_test.supports_reftable():

tests/test_git_status.py

@@ -0,0 +1,210 @@
+# Copyright (C) 2026 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for the git_status.py module."""
+
+import os
+from typing import Any, List
+from unittest import mock
+
+import pytest
+
+import git_status
+
+
+def test_parse_porcelain_v2_branch_and_paths() -> None:
+    output = (
+        b"# branch.oid " + b"1" * 40 + b"\0"
+        b"# branch.head topic\0"
+        b"# branch.upstream origin/main\0"
+        b"# branch.ab +2 -3\0"
+        b"# stash 1\0"
+        b"1 M. N... 100644 100644 100644 "
+        + b"1" * 40
+        + b" "
+        + b"2" * 40
+        + b" staged name\0"
+        b"1 .M N... 100644 100644 100644 "
+        + b"1" * 40
+        + b" "
+        + b"2" * 40
+        + b" worktree name\0"
+        b"2 R. N... 100644 100644 100644 "
+        + b"1" * 40
+        + b" "
+        + b"2" * 40
+        + b" R075 renamed\0old name\0"
+        b"? untracked\0"
+    )
+
+    status = git_status.ParsePorcelainV2(output)
+
+    assert status.current_branch == "topic"
+    assert status.upstream == "origin/main"
+    assert (status.ahead, status.behind, status.stash_count) == (2, 3, 1)
+    assert status.index_changes["staged name"].status == "M"
+    assert status.worktree_changes["worktree name"].status == "M"
+    renamed = status.index_changes["renamed"]
+    assert (renamed.src_path, renamed.level) == ("old name", "75")
+    assert status.untracked == ["untracked"]
+
+
+def test_parse_porcelain_v2_unmerged_and_non_utf8_path() -> None:
+    path = b"bad-\xff-name"
+    output = (
+        b"u UU N... 100644 100644 100644 100644 "
+        + b"1" * 40
+        + b" "
+        + b"2" * 40
+        + b" "
+        + b"3" * 40
+        + b" "
+        + path
+        + b"\0"
+    )
+
+    status = git_status.ParsePorcelainV2(output)
+    decoded = os.fsdecode(path)
+
+    assert status.index_changes[decoded].status == "U"
+    assert status.worktree_changes[decoded].status == "U"
+    assert os.fsencode(status.index_changes[decoded].path) == path
+
+
+def test_untracked_only_respects_consider_untracked() -> None:
+    status = git_status.ParsePorcelainV2(b"? new file\0")
+
+    assert status.is_dirty()
+    assert not status.is_dirty(consider_untracked=False)
+
+
+def test_branch_headers_preserve_non_ascii_names() -> None:
+    branch = "tópico"
+    status = git_status.ParsePorcelainV2(
+        b"# branch.oid " + b"1" * 40 + b"\0"
+        b"# branch.head " + os.fsencode(branch) + b"\0"
+    )
+
+    assert status.current_branch == branch
+
+
+def test_quick_ahead_behind_is_recorded_as_unknown() -> None:
+    status = git_status.ParsePorcelainV2(b"# branch.ab +? -?\0")
+
+    assert (status.ahead, status.behind) == (0, 0)
+    assert not status.has_ahead_behind
+
+
+def test_unknown_head_is_not_a_current_branch() -> None:
+    status = git_status.ParsePorcelainV2(b"# branch.head (unknown)\0")
+
+    assert status.current_branch is None
+
+
+def test_malformed_output_is_rejected() -> None:
+    with pytest.raises(git_status.StatusParseError):
+        git_status.ParsePorcelainV2(b"2 R. truncated\0")
+
+
+def test_malformed_branch_ab_is_rejected() -> None:
+    with pytest.raises(git_status.StatusParseError):
+        git_status.ParsePorcelainV2(b"# branch.ab not-a-valid-ab\0")
+
+
+def test_ignored_records_are_skipped() -> None:
+    status = git_status.ParsePorcelainV2(b"! ignored_file\0")
+    assert not status.is_dirty()
+    assert status.untracked == []
+
+
+def test_get_status_uses_versioned_machine_options(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    commands = []
+
+    class FakeGitCommand:
+        def __init__(
+            self, _project: Any, cmdv: List[str], **kwargs: Any
+        ) -> None:
+            commands.append((cmdv, kwargs))
+            self.stdout = b""
+
+        def Wait(self) -> int:
+            return 0
+
+    monkeypatch.setattr(git_status, "GitCommand", FakeGitCommand)
+    monkeypatch.setattr(git_status, "git_require", lambda _version: True)
+
+    git_status.GetStatus(
+        mock.sentinel.project,
+        mock.sentinel.gitdir,
+        untracked_files="no",
+        branch=True,
+        ahead_behind=True,
+        show_stash=True,
+    )
+
+    cmd, kwargs = commands[0]
+    assert cmd == [
+        "status",
+        "--porcelain=v2",
+        "-z",
+        "--ignore-submodules=all",
+        "--untracked-files=no",
+        "--branch",
+        "--ahead-behind",
+        "--renames",
+        "--show-stash",
+    ]
+    assert kwargs["capture_stdout_bytes"]
+
+
+def test_get_status_rejects_git_before_2_11(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setattr(git_status, "git_require", lambda _version: False)
+
+    with pytest.raises(git_status.UnsupportedStatusError):
+        git_status.GetStatus(mock.sentinel.project, mock.sentinel.gitdir)
+
+
+def test_get_status_omits_stash_header_before_2_35(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    commands = []
+
+    class FakeGitCommand:
+        def __init__(
+            self, _project: Any, cmdv: List[str], **_kwargs: Any
+        ) -> None:
+            commands.append(cmdv)
+            self.stdout = b""
+
+        def Wait(self) -> int:
+            return 0
+
+    monkeypatch.setattr(git_status, "GitCommand", FakeGitCommand)
+    monkeypatch.setattr(
+        git_status,
+        "git_require",
+        lambda version: version <= (2, 34, 0),
+    )
+
+    git_status.GetStatus(
+        mock.sentinel.project,
+        mock.sentinel.gitdir,
+        show_stash=True,
+    )
+
+    assert "--show-stash" not in commands[0]

tests/test_git_superproject.py

@@ -542,14 +542,15 @@ class SuperprojectTestCase(unittest.TestCase):
             with mock.patch(
                 "git_superproject.GitCommand", autospec=True
             ) as mock_git_command:
-                with mock.patch(
+                with mock.patch.object(
-                    "git_superproject.GitRefs.get", autospec=True
+                    self._superproject, "_GetRef"
-                ) as mock_git_refs:
+                ) as get_ref:
                     instance = mock_git_command.return_value
                     instance.Wait.return_value = 0
-                    mock_git_refs.side_effect = ["", "1234"]
+                    get_ref.side_effect = ["", "1234"]
 
                     self.assertTrue(self._superproject._Fetch())
+                    get_ref.assert_called_with("refs/heads/main")
                     self.assertEqual(
                         # TODO: Once we require Python 3.8+,
                         #  use 'mock_git_command.call_args.args'.
@@ -572,6 +573,7 @@ class SuperprojectTestCase(unittest.TestCase):
 
                     # If branch for revision exists, set as --negotiation-tip.
                     self.assertTrue(self._superproject._Fetch())
+                    get_ref.assert_called_with("refs/heads/main")
                     self.assertEqual(
                         # TODO: Once we require Python 3.8+,
                         #  use 'mock_git_command.call_args.args'.
@@ -593,3 +595,21 @@ class SuperprojectTestCase(unittest.TestCase):
                             ],
                         ),
                     )
+
+    def test_GetRef_resolves_only_the_requested_ref(self) -> None:
+        command = mock.MagicMock(stdout="1234\n")
+        command.Wait.return_value = 0
+        with mock.patch(
+            "git_superproject.GitCommand", return_value=command
+        ) as git_command:
+            self.assertEqual("1234", self._superproject._GetRef("HEAD"))
+
+        git_command.assert_called_once_with(
+            None,
+            ["rev-parse", "--verify", "--quiet", "HEAD"],
+            gitdir=self._superproject._work_git,
+            bare=True,
+            capture_stdout=True,
+            capture_stderr=True,
+            log_as_error=False,
+        )

tests/test_git_trace2_event_log.py

@@ -33,7 +33,7 @@ import platform_utils
 
 def server_logging_thread(
     socket_path: str,
-    server_ready: threading.Condition,
+    server_ready: threading.Event,
     received_traces: List[str],
 ) -> None:
     """Helper function to receive logs over a Unix domain socket.
@@ -43,8 +43,7 @@ def server_logging_thread(
 
     Args:
         socket_path: path to a Unix domain socket on which to listen for traces
-        server_ready: a threading.Condition used to signal to the caller that
+        server_ready: event set when the server is ready to accept connections
-            this thread is ready to accept connections
         received_traces: a list to which received traces will be appended (after
             decoding to a utf-8 string).
     """
@@ -53,8 +52,7 @@ def server_logging_thread(
     with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as sock:
         sock.bind(socket_path)
         sock.listen(0)
-        with server_ready:
+        server_ready.set()
-            server_ready.notify()
         with sock.accept()[0] as conn:
             while True:
                 recved = conn.recv(4096)
@@ -404,7 +402,7 @@ def test_write_socket(event_log: git_trace2_event_log.EventLog) -> None:
     received_traces: List[str] = []
     with tempfile.TemporaryDirectory(prefix="test_server_sockets") as tempdir:
         socket_path = os.path.join(tempdir, "server.sock")
-        server_ready = threading.Condition()
+        server_ready = threading.Event()
         # Start "server" listening on Unix domain socket at socket_path.
         server_thread = threading.Thread(
             target=server_logging_thread,
@@ -412,9 +410,7 @@ def test_write_socket(event_log: git_trace2_event_log.EventLog) -> None:
         )
         try:
             server_thread.start()
-
+            server_ready.wait(timeout=120)
-            with server_ready:
-                server_ready.wait(timeout=120)
 
             event_log.StartEvent([])
             path = event_log.Write(path=f"af_unix:{socket_path}")

tests/test_hooks.py

@@ -15,6 +15,7 @@
 """Unittests for the hooks.py module."""
 
 from io import StringIO
+from pathlib import Path
 import sys
 
 import pytest
@@ -108,11 +109,11 @@ def test_post_sync_argument_validation() -> None:
 
 
 @pytest.mark.parametrize("yes_val", (True, False))
-def test_repo_upload_yes_arg(tmp_path, yes_val: bool) -> None:
+def test_repo_upload_yes_arg(tmp_path: Path, yes_val: bool) -> None:
     """Test that yes is passed in kwargs during hook execution."""
 
     class FakeProject:
-        def __init__(self, worktree):
+        def __init__(self, worktree: str) -> None:
             self.worktree = worktree
             self.enabled_repo_hooks = ["pre-upload"]
             self.config = None
@@ -139,3 +140,64 @@ def main(project_list, **kwargs):
 
     assert res is True
     assert project_list == [yes_val]
+
+
+@pytest.mark.parametrize("fix_val", (True, False))
+def test_repo_upload_fix_arg(tmp_path: Path, fix_val: bool) -> None:
+    """Test that fix is passed in kwargs during hook execution."""
+
+    class FakeProject:
+        def __init__(self, worktree: str) -> None:
+            self.worktree = worktree
+            self.enabled_repo_hooks = ["pre-upload"]
+            self.config = None
+
+    hook_file = tmp_path / "pre-upload.py"
+
+    hook_content = """
+def main(project_list, **kwargs):
+    project_list.append(kwargs.get("fix"))
+"""
+    hook_file.write_text(hook_content)
+
+    hook = hooks.RepoHook(
+        hook_type="pre-upload",
+        hooks_project=FakeProject(str(tmp_path)),
+        repo_topdir=str(tmp_path),
+        manifest_url="https://gerrit",
+        allow_all_hooks=True,
+        fix=fix_val,
+    )
+
+    project_list = []
+    res = hook.Run(project_list=project_list, worktree_list=[])
+
+    assert res is True
+    assert project_list == [fix_val]
+
+
+def test_from_subcmd_without_fix_option() -> None:
+    """Test that FromSubcmd works when opt does not have fix attribute."""
+
+    class Remote:
+        url = "https://gerrit"
+
+    class FakeManifest:
+        repo_hooks_project = None
+        topdir = "/fake/topdir"
+
+        class manifestProject:
+            @staticmethod
+            def GetRemote(name: str) -> "Remote":
+                return Remote()
+
+        class contactinfo:
+            bugurl = "https://bugs"
+
+    class FakeOpt:
+        bypass_hooks = False
+        allow_all_hooks = False
+        ignore_hooks = False
+
+    hook = hooks.RepoHook.FromSubcmd(FakeManifest(), FakeOpt(), "post-sync")
+    assert hook._fix is False

tests/test_release_update_manpages.py

@@ -0,0 +1,43 @@
+# Copyright (C) 2026 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests for the release/update-manpages wrapper."""
+
+import runpy
+import sys
+from types import ModuleType
+
+import pytest
+import utils_for_test
+
+
+UPDATE_MANPAGES_SCRIPT = (
+    utils_for_test.THIS_DIR.parent / "release" / "update-manpages"
+)
+
+
+def test_wrapper_does_not_run_main_for_multiprocessing_child(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Do not rerun main when multiprocessing re-executes the wrapper."""
+    fake_update_manpages = ModuleType("update_manpages")
+
+    # Mock this because the real module requires newer Python versions than
+    # our unittest framework does.
+    monkeypatch.setitem(sys.modules, "update_manpages", fake_update_manpages)
+
+    runpy.run_path(
+        str(UPDATE_MANPAGES_SCRIPT),
+        run_name="__mp_main__",
+    )

tests/test_subcmds_cherry_pick.py

@@ -0,0 +1,85 @@
+# Copyright (C) 2026 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for subcmds/cherry_pick.py."""
+
+from unittest import mock
+
+import pytest
+
+from error import GitError
+from git_command import GitCommand
+from subcmds import cherry_pick
+
+
+def test_resolve_reference_uses_one_typed_batch_request(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    oid = "1" * 40
+    commit = "tree " + "2" * 40 + "\n\nSubject 🚀\n\nBody\n"
+    output = oid + " commit " + str(len(commit.encode("utf-8"))) + "\n"
+    output += commit + "\n"
+    command = mock.create_autospec(GitCommand, instance=True)
+    command.stdout = output
+    command.stderr = ""
+    command.Wait.return_value = 0
+    run_git = mock.create_autospec(GitCommand, return_value=command)
+    monkeypatch.setattr(cherry_pick, "GitCommand", run_git)
+
+    resolved, contents = cherry_pick.CherryPick()._ResolveReference("topic")
+
+    assert resolved == oid
+    assert contents == commit
+    run_git.assert_called_once_with(
+        None,
+        ["cat-file", "--batch"],
+        input="topic^{commit}\n",
+        capture_stdout=True,
+        capture_stderr=True,
+        verify_command=True,
+    )
+
+
+def test_resolve_reference_rejects_missing_object(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    command = mock.create_autospec(GitCommand, instance=True)
+    command.stdout = "topic^{commit} missing\n"
+    command.stderr = ""
+    command.Wait.return_value = 0
+    monkeypatch.setattr(
+        cherry_pick,
+        "GitCommand",
+        mock.create_autospec(GitCommand, return_value=command),
+    )
+
+    with pytest.raises(GitError, match="commit topic not found"):
+        cherry_pick.CherryPick()._ResolveReference("topic")
+
+
+def test_resolve_reference_rejects_ambiguous_object(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    command = mock.create_autospec(GitCommand, instance=True)
+    command.stdout = "topic^{commit} ambiguous\n"
+    command.stderr = ""
+    command.Wait.return_value = 0
+    monkeypatch.setattr(
+        cherry_pick,
+        "GitCommand",
+        mock.create_autospec(GitCommand, return_value=command),
+    )
+
+    with pytest.raises(GitError, match="commit topic not found"):
+        cherry_pick.CherryPick()._ResolveReference("topic")

tests/test_subcmds_forall.py

@@ -17,7 +17,9 @@
 import contextlib
 import io
 from pathlib import Path
+from unittest import mock
 
+import pytest
 import utils_for_test
 
 import manifest_xml
@@ -105,3 +107,57 @@ def test_forall_all_projects_called_once(tmp_path: Path) -> None:
     line_count = sum(1 for x in output.splitlines() if x)
     # Verify that we didn't get more lines than expected.
     assert line_count == 8
+
+
+@pytest.mark.parametrize(
+    ("regex_option", "inverse"),
+    [
+        ("-r", False),
+        ("-i", True),
+    ],
+    ids=("regex", "inverse-regex"),
+)
+def test_forall_regex_modes_pass_groups_to_find_projects(
+    tmp_path: Path,
+    regex_option: str,
+    inverse: bool,
+) -> None:
+    """Pass --groups through in regex modes."""
+    manifest = _create_manifest_with_8_projects(tmp_path)
+
+    cmd = subcmds.forall.Forall()
+    cmd.manifest = manifest
+
+    opts, args = cmd.OptionParser.parse_args(
+        [
+            regex_option,
+            "--groups",
+            "special",
+            "project",
+            "-c",
+            "true",
+        ]
+    )
+
+    with mock.patch.object(
+        cmd,
+        "FindProjects",
+        return_value=[],
+    ) as find_projects, mock.patch.object(
+        cmd,
+        "ExecuteInParallel",
+        return_value=0,
+    ):
+        cmd.Execute(opts, args)
+
+    expected_kwargs = {
+        "groups": "special",
+        "all_manifests": True,
+    }
+    if inverse:
+        expected_kwargs["inverse"] = True
+
+    find_projects.assert_called_once_with(
+        ["project"],
+        **expected_kwargs,
+    )

tests/test_subcmds_info.py

@@ -208,7 +208,7 @@ def test_get_project_data_uses_head_revision() -> None:
     project.name = "foo"
     project.worktree = "/path/to/foo"
     project.revisionExpr = "refs/heads/main"
-    project.GetBranches.return_value = []
+    project.GetBranches.return_value = {}
 
     # GetHeadRevisionId() returns a SHA, it should be used.
     project.GetHeadRevisionId.return_value = "head_sha_12345"
@@ -235,7 +235,9 @@ def test_json_with_projects(capsys) -> None:
     project.name = "foo"
     project.worktree = "/path/to/foo"
     project.revisionExpr = "refs/heads/main"
-    project.GetBranches.return_value = {"branch1": mock.MagicMock()}
+    branch = mock.MagicMock()
+    branch.current = True
+    project.GetBranches.return_value = {"branch1": branch}
     project.GetHeadRevisionId.return_value = "head_sha_12345"
     project.CurrentBranch = "branch1"
 
@@ -253,3 +255,115 @@ def test_json_with_projects(capsys) -> None:
     assert project_data["manifest_revision"] == "refs/heads/main"
     assert project_data["local_branches"] == ["branch1"]
     assert project_data["current_branch"] == "branch1"
+
+
+def test_diff_commits_uses_one_left_right_walk() -> None:
+    """Local and remote commits are partitioned from one rev-list."""
+    project = mock.MagicMock()
+    project.work_git.rev_list.return_value = [
+        "<11111111 local commit",
+        ">22222222 remote commit",
+    ]
+
+    local, remote = info.Info._GetDiffCommits(project, "refs/remotes/m/main")
+
+    assert local == ["11111111 local commit"]
+    assert remote == ["22222222 remote commit"]
+    project.work_git.rev_list.assert_called_once_with(
+        "--left-right",
+        "--abbrev=8",
+        "--abbrev-commit",
+        "--pretty=oneline",
+        "HEAD...refs/remotes/m/main",
+        "--",
+    )
+
+
+def test_diff_commits_falls_back_to_bare_git_when_no_worktree() -> None:
+    """Bare or worktree-less projects fall back to bare_git for history walk."""
+    project = mock.MagicMock()
+    project.work_git = None
+    project.bare_git.rev_list.return_value = [
+        "<11111111 local commit",
+        ">22222222 remote commit",
+    ]
+
+    local, remote = info.Info._GetDiffCommits(project, "refs/remotes/m/main")
+
+    assert local == ["11111111 local commit"]
+    assert remote == ["22222222 remote commit"]
+    project.bare_git.rev_list.assert_called_once_with(
+        "--left-right",
+        "--abbrev=8",
+        "--abbrev-commit",
+        "--pretty=oneline",
+        "HEAD...refs/remotes/m/main",
+        "--",
+    )
+
+
+def test_diff_commits_empty_output() -> None:
+    """Empty rev-list output produces empty local and remote commit lists."""
+    project = mock.MagicMock()
+    project.work_git.rev_list.return_value = []
+
+    local, remote = info.Info._GetDiffCommits(project, "refs/remotes/m/main")
+
+    assert local == []
+    assert remote == []
+
+
+def test_get_current_branch() -> None:
+    """_GetCurrentBranch identifies the branch with current=True."""
+    b1 = mock.MagicMock(current=False)
+    b2 = mock.MagicMock(current=True)
+    assert info.Info._GetCurrentBranch({"b1": b1, "b2": b2}) == "b2"
+    assert info.Info._GetCurrentBranch({"b1": b1}) is None
+    assert info.Info._GetCurrentBranch({}) is None
+
+
+def test_overview_helper_current_branch_filters_before_uploadable(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """_OverviewHelper only checks uploadable state for the current branch."""
+    project = mock.MagicMock()
+    project.RelPath.return_value = "proj"
+    b1 = mock.MagicMock(current=False)
+    b2 = mock.MagicMock(current=True)
+    project.GetBranches.return_value = {"b1": b1, "b2": b2}
+    uploadable = mock.MagicMock(commits=["c1"], date="2026-09-21")
+    uploadable.name = "b2"
+    project.GetUploadableBranch.return_value = uploadable
+    monkeypatch.setattr(
+        info.Info,
+        "get_parallel_context",
+        lambda: {"projects": [project]},
+    )
+    opt = mock.MagicMock(current_branch=True, this_manifest_only=False)
+
+    result = info.Info._OverviewHelper(0, opt)
+
+    project.GetUploadableBranch.assert_called_once_with("b2")
+    assert len(result) == 1
+    assert result[0].name == "b2"
+    assert result[0].is_current is True
+
+
+def test_overview_helper_current_branch_detached_head_skips_uploadable(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """_OverviewHelper skips GetUploadableBranch when detached with -b."""
+    project = mock.MagicMock()
+    b1 = mock.MagicMock(current=False)
+    project.GetBranches.return_value = {"b1": b1}
+    monkeypatch.setattr(
+        info.Info,
+        "get_parallel_context",
+        lambda: {"projects": [project]},
+    )
+    opt = mock.MagicMock(current_branch=True, this_manifest_only=False)
+
+    result = info.Info._OverviewHelper(0, opt)
+
+    project.GetUploadableBranch.assert_not_called()
+    assert result == []

tests/test_subcmds_list.py

@@ -0,0 +1,57 @@
+# Copyright (C) 2026 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for the list subcmd."""
+
+from typing import List, Optional
+from unittest import mock
+
+import pytest
+
+import subcmds
+
+
+@pytest.mark.parametrize(
+    ("extra_args", "expected_groups", "expected_missing_ok"),
+    [
+        (["--groups", "special"], "special", None),
+        (["--all"], None, True),
+    ],
+    ids=("groups", "all"),
+)
+def test_list_regex_passes_groups_and_all(
+    extra_args: List[str],
+    expected_groups: Optional[str],
+    expected_missing_ok: Optional[bool],
+) -> None:
+    """Pass --groups and --all through in regex mode."""
+    cmd = subcmds.list.List()
+
+    opts, args = cmd.OptionParser.parse_args(
+        ["--regex", *extra_args, "project"]
+    )
+
+    with mock.patch.object(
+        cmd,
+        "FindProjects",
+        return_value=[],
+    ) as find_projects:
+        cmd.Execute(opts, args)
+
+    find_projects.assert_called_once_with(
+        ["project"],
+        groups=expected_groups,
+        missing_ok=expected_missing_ok,
+        all_manifests=True,
+    )

tests/test_subcmds_rebase.py

@@ -14,6 +14,9 @@
 
 """Unittests for the subcmds/rebase.py module."""
 
+import contextlib
+import io
+from types import SimpleNamespace
 from unittest import mock
 
 from error import GitError
@@ -48,3 +51,41 @@ def test_resolve_onto_manifest_fallback() -> None:
     assert res == "main"
     project.GetRemote.assert_called_once()
     remote.ToLocal.assert_called_once_with("main")
+
+
+def test_execute_delegates_autostash_to_rebase() -> None:
+    """--auto-stash is one rebase process, including staged-only changes."""
+    cmd = rebase.Rebase()
+    cmd.manifest = mock.MagicMock()
+    cmd.git_event_log = mock.MagicMock()
+    project = mock.MagicMock()
+    project.CurrentBranch = "topic"
+    project.RelPath.return_value = "project"
+    branch = mock.MagicMock()
+    branch.LocalMerge = "refs/remotes/origin/main"
+    project.GetBranch.return_value = branch
+    cmd.GetProjects = mock.MagicMock(return_value=[project])
+    opt = SimpleNamespace(
+        interactive=False,
+        fail_fast=False,
+        whitespace=None,
+        quiet=False,
+        force_rebase=False,
+        ff=True,
+        autosquash=False,
+        auto_stash=True,
+        onto_manifest=False,
+        this_manifest_only=False,
+    )
+    git_command = mock.MagicMock()
+    git_command.Wait.return_value = 0
+
+    with mock.patch.object(
+        rebase, "GitCommand", return_value=git_command
+    ) as run_git, contextlib.redirect_stdout(io.StringIO()):
+        assert cmd.Execute(opt, []) == 0
+
+    run_git.assert_called_once_with(
+        project,
+        ["rebase", "--autostash", "refs/remotes/origin/main"],
+    )

tests/test_subcmds_status.py

@@ -185,6 +185,96 @@ def test_status_without_orphans(
     assert lines[1] == " -m\tREADME"
 
 
+def test_status_staged_and_unstaged_same_path(
+    repo_client_checkout: Tuple[Path, manifest_xml.XmlManifest],
+) -> None:
+    """A path changed on both sides of the index renders both states."""
+    topdir, manifest = repo_client_checkout
+    project_path = next(iter(manifest.paths.keys()))
+    project_worktree = topdir / project_path
+    readme = project_worktree / "README"
+    readme.write_text("staged")
+    subprocess.check_call(["git", "add", "README"], cwd=project_worktree)
+    readme.write_text("unstaged")
+
+    with contextlib.redirect_stdout(io.StringIO()) as stdout:
+        _run_status(manifest, [])
+
+    lines = _status_lines(stdout.getvalue())
+    assert lines[1] == " Mm\tREADME"
+
+
+def test_status_forces_staged_rename_detection(
+    repo_client_checkout: Tuple[Path, manifest_xml.XmlManifest],
+) -> None:
+    """The snapshot preserves rename scores despite user status config."""
+    topdir, manifest = repo_client_checkout
+    project_path = next(iter(manifest.paths.keys()))
+    project_worktree = topdir / project_path
+    subprocess.check_call(
+        ["git", "config", "status.renames", "false"], cwd=project_worktree
+    )
+    subprocess.check_call(
+        ["git", "mv", "README", "RENAMED"], cwd=project_worktree
+    )
+
+    with contextlib.redirect_stdout(io.StringIO()) as stdout:
+        _run_status(manifest, [])
+
+    lines = _status_lines(stdout.getvalue())
+    assert lines[1] == " R-\tREADME => RENAMED (100%)"
+
+
+def test_detached_clean_status_is_suppressed(
+    repo_client_checkout: Tuple[Path, manifest_xml.XmlManifest],
+) -> None:
+    """A clean detached checkout keeps returning CLEAN without output."""
+    topdir, manifest = repo_client_checkout
+    project_path = next(iter(manifest.paths.keys()))
+    subprocess.check_call(
+        ["git", "checkout", "-q", "--detach", "HEAD"],
+        cwd=topdir / project_path,
+    )
+
+    with contextlib.redirect_stdout(io.StringIO()) as stdout:
+        _run_status(manifest, [])
+
+    assert _status_lines(stdout.getvalue()) == [
+        "nothing to commit (working directory clean)"
+    ]
+
+
+def test_status_unmerged_path_matches_legacy_display(
+    repo_client_checkout: Tuple[Path, manifest_xml.XmlManifest],
+) -> None:
+    """Porcelain-v2 unmerged records render as index U and worktree u."""
+    topdir, manifest = repo_client_checkout
+    project_path = next(iter(manifest.paths.keys()))
+    worktree = topdir / project_path
+    subprocess.check_call(
+        ["git", "checkout", "-q", "-b", "other"], cwd=worktree
+    )
+    (worktree / "README").write_text("other")
+    subprocess.check_call(["git", "commit", "-qam", "other"], cwd=worktree)
+    subprocess.check_call(["git", "checkout", "-q", "main"], cwd=worktree)
+    (worktree / "README").write_text("main")
+    subprocess.check_call(["git", "commit", "-qam", "main"], cwd=worktree)
+    merge = subprocess.run(
+        ["git", "merge", "other"],
+        cwd=worktree,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        check=False,
+    )
+    assert merge.returncode != 0
+
+    with contextlib.redirect_stdout(io.StringIO()) as stdout:
+        _run_status(manifest, [])
+
+    lines = _status_lines(stdout.getvalue())
+    assert lines[1] == " Uu\tREADME"
+
+
 def test_status_with_orphans_and_modified_file(
     repo_client_checkout: Tuple[Path, manifest_xml.XmlManifest],
 ) -> None:
@@ -304,6 +394,10 @@ def test_status_branch_ahead_of_upstream(
     project_worktree = topdir / project_path
 
     _setup_remote_tracking_branch(manifest, "feature")
+    subprocess.check_call(
+        ["git", "config", "status.aheadBehind", "false"],
+        cwd=project_worktree,
+    )
     subprocess.check_call(
         ["git", "commit", "-q", "--allow-empty", "-m", "c1"],
         cwd=project_worktree,
@@ -451,3 +545,20 @@ def test_status_branch_synced_no_ahead_behind(
     lines = _status_lines(stdout.getvalue())
     assert len(lines) == 1
     _assert_project_header(lines[0], project_path, "synced")
+
+
+def test_status_non_utf8_path(
+    repo_client_checkout: Tuple[Path, manifest_xml.XmlManifest],
+) -> None:
+    """Non-UTF-8 pathnames render without crashing."""
+    topdir, manifest = repo_client_checkout
+    project_path = next(iter(manifest.paths.keys()))
+    project_worktree = topdir / project_path
+    bad_path = project_worktree / os.fsdecode(b"bad-\xff-name")
+    bad_path.write_bytes(b"content")
+
+    with contextlib.redirect_stdout(io.StringIO()) as stdout:
+        _run_status(manifest, [])
+
+    lines = _status_lines(stdout.getvalue())
+    assert any("bad-" in line for line in lines)

tests/test_subcmds_sync.py

@@ -13,12 +13,15 @@
 # limitations under the License.
 """Unittests for the subcmds/sync.py module."""
 
+import contextlib
 import json
+import optparse
 import os
 from pathlib import Path
 import shutil
 import tempfile
 import time
+from typing import Dict, List, Optional, Tuple
 import unittest
 from unittest import mock
 
@@ -27,6 +30,7 @@ import pytest
 import command
 from error import GitError
 from error import RepoExitError
+import git_status
 import manifest_xml
 from project import SyncNetworkHalfResult
 from subcmds import sync
@@ -212,6 +216,31 @@ def test_sync_update_projects_revision_id_respects_groups(tmp_path: Path):
             assert kwargs.get("groups") == "group1"
 
 
+@pytest.mark.parametrize(
+    "generate_manpages, expected_default",
+    [
+        (False, "7; based on number of CPU cores"),
+        (True, "based on number of CPU cores"),
+    ],
+    ids=("interactive", "manpages"),
+)
+def test_jobs_checkout_help_default(
+    generate_manpages: bool,
+    expected_default: str,
+) -> None:
+    """Test checkout-jobs default help in interactive and manpage modes."""
+    with mock.patch.object(sync, "DEFAULT_LOCAL_JOBS", 7), mock.patch.object(
+        command,
+        "GENERATE_MANPAGES",
+        generate_manpages,
+    ):
+        help_text = " ".join(sync.Sync().OptionParser.format_help().split())
+
+    assert f"defaults to --jobs or {expected_default}" in help_text
+    if generate_manpages:
+        assert "defaults to --jobs or 7" not in help_text
+
+
 # Used to patch os.cpu_count() for reliable results.
 OS_CPU_COUNT = 24
 
@@ -491,22 +520,49 @@ class LocalSyncState(unittest.TestCase):
 
 
 class FakeProject:
-    def __init__(self, relpath, name=None, objdir=None):
+    def __init__(
+        self,
+        relpath: str,
+        name: Optional[str] = None,
+        objdir: Optional[str] = None,
+        parent: Optional["FakeProject"] = None,
+        is_derived: bool = False,
+        revisionId: Optional[str] = None,
+        gitlink_path: Optional[str] = None,
+        path_prefix: str = "",
+    ) -> None:
         self.relpath = relpath
+        self.path_prefix = path_prefix
         self.name = name or relpath
         self.objdir = objdir or relpath
         self.worktree = relpath
-        self.parent = None
+        self.parent = parent
+        self.is_derived = is_derived
+        self.revisionId = revisionId
+        self.gitlink_path = gitlink_path
 
         self.use_git_worktrees = False
         self.UseAlternates = False
+        self.UseReprojectCmd = False
         self.manifest = mock.MagicMock()
         self.manifest.GetProjectsWithName.return_value = [self]
         self.config = mock.MagicMock()
         self.EnableRepositoryExtension = mock.MagicMock()
 
-    def RelPath(self, local=None):
+    @property
-        return self.relpath
+    def Derived(self) -> bool:
+        return self.is_derived
+
+    def SetRevision(
+        self, revisionExpr: str, revisionId: Optional[str] = None
+    ) -> None:
+        self.revisionExpr = revisionExpr
+        self.revisionId = revisionId or revisionExpr
+
+    def RelPath(self, local: bool = True) -> str:
+        if local:
+            return self.relpath
+        return os.path.join(self.path_prefix, self.relpath)
 
     def __str__(self):
         return f"project: {self.relpath}"
@@ -614,6 +670,180 @@ class SafeCheckoutOrder(unittest.TestCase):
         )
 
 
+class NestedProjects(unittest.TestCase):
+    def test_flat_manifest(self) -> None:
+        p_foo = FakeProject("foo")
+        p_foo_bar = FakeProject("foo-bar")
+        self.assertEqual(sync._NestedProjects([p_foo, p_foo_bar]), [])
+
+    def test_nested_paths(self) -> None:
+        p_foo = FakeProject("foo")
+        p_foo_bar = FakeProject("foo/bar")
+        p_foo_bar_baz = FakeProject("foo/bar/baz")
+        self.assertEqual(
+            sync._NestedProjects([p_foo_bar_baz, p_foo, p_foo_bar]),
+            [p_foo_bar, p_foo_bar_baz],
+        )
+
+    def test_submodule_of_a_parent(self) -> None:
+        parent = FakeProject("foo")
+        sub = FakeProject("foo/sub", parent=parent, is_derived=True)
+        self.assertEqual(sync._NestedProjects([parent, sub]), [sub])
+
+
+class ParentFirstBatches(unittest.TestCase):
+    def test_no_submodules(self) -> None:
+        p_a = FakeProject("a")
+        p_a_b = FakeProject("a/b")
+        out = sync._ParentFirstBatches([p_a, p_a_b])
+        self.assertEqual(out, [[p_a, p_a_b]])
+
+    def test_submodules_follow_their_parent(self) -> None:
+        p_a = FakeProject("a")
+        p_a_b = FakeProject("a/b", parent=p_a, is_derived=True)
+        p_a_b_c = FakeProject("a/b/c", parent=p_a_b, is_derived=True)
+        out = sync._ParentFirstBatches([p_a_b_c, p_a, p_a_b])
+        self.assertEqual(out, [[p_a], [p_a_b], [p_a_b_c]])
+
+
+class RefreshDerivedRevisions(unittest.TestCase):
+    def _parent_with_submodules(self, **gitlinks: str) -> FakeProject:
+        p_a = FakeProject("a")
+        p_a.GetSubmoduleRevisions = mock.Mock(return_value=gitlinks)
+        return p_a
+
+    def _submodule(self, parent: FakeProject, path: str) -> FakeProject:
+        return FakeProject(
+            f"a/{path}", parent=parent, is_derived=True, gitlink_path=path
+        )
+
+    def test_reads_each_parent_once(self) -> None:
+        p_a = self._parent_with_submodules(b="beef1234", c="cafe1234")
+        p_a_b = self._submodule(p_a, "b")
+        p_a_c = self._submodule(p_a, "c")
+
+        sync._RefreshDerivedRevisions([p_a, p_a_b, p_a_c])
+
+        p_a.GetSubmoduleRevisions.assert_called_once_with()
+        self.assertEqual(p_a_b.revisionId, "beef1234")
+        self.assertEqual(p_a_c.revisionId, "cafe1234")
+
+    def test_reuses_gitlinks_read_for_an_earlier_level(self) -> None:
+        p_a = self._parent_with_submodules(b="beef1234", c="cafe1234")
+        p_a_b = self._submodule(p_a, "b")
+        p_a_c = self._submodule(p_a, "c")
+        submodule_revisions = {}
+
+        sync._RefreshDerivedRevisions([p_a_b], submodule_revisions)
+        sync._RefreshDerivedRevisions([p_a_c], submodule_revisions)
+
+        p_a.GetSubmoduleRevisions.assert_called_once_with()
+        self.assertEqual(p_a_c.revisionId, "cafe1234")
+
+    def test_tells_apart_projects_with_the_same_path(self) -> None:
+        # Paths are relative to their own (sub)manifest, so two projects can
+        # share one.
+        first = self._parent_with_submodules(b="beef1234")
+        second = self._parent_with_submodules(b="cafe1234")
+        first_sub = self._submodule(first, "b")
+        second_sub = self._submodule(second, "b")
+        submodule_revisions = {}
+
+        sync._RefreshDerivedRevisions([first_sub], submodule_revisions)
+        sync._RefreshDerivedRevisions([second_sub], submodule_revisions)
+
+        self.assertEqual(first_sub.revisionId, "beef1234")
+        self.assertEqual(second_sub.revisionId, "cafe1234")
+
+    def test_ignores_projects_from_the_manifest(self) -> None:
+        p_a = self._parent_with_submodules()
+
+        sync._RefreshDerivedRevisions([p_a])
+
+        p_a.GetSubmoduleRevisions.assert_not_called()
+
+    def test_reports_submodules_removed_from_their_parent(self) -> None:
+        p_a = self._parent_with_submodules(b="beef1234")
+        p_a_c = self._submodule(p_a, "c")
+
+        removed = sync._RefreshDerivedRevisions([p_a, p_a_c])
+
+        self.assertEqual(removed, [p_a_c])
+
+    def test_keeps_submodules_of_an_unreadable_parent(self) -> None:
+        p_a = FakeProject("a")
+        p_a.GetSubmoduleRevisions = mock.Mock(return_value=None)
+        p_a_b = FakeProject(
+            "a/b",
+            parent=p_a,
+            is_derived=True,
+            revisionId="stale",
+            gitlink_path="b",
+        )
+
+        removed = sync._RefreshDerivedRevisions([p_a, p_a_b])
+
+        self.assertEqual(removed, [])
+        self.assertEqual(p_a_b.revisionId, "stale")
+
+
+class FetchParentFirst(unittest.TestCase):
+    def test_submodules_are_fetched_after_their_parent(self) -> None:
+        cmd = sync.Sync()
+        cmd._fetch_times = mock.Mock()
+        cmd._fetch_times.Get = mock.Mock(return_value=0)
+
+        calls = []
+        p_a = FakeProject("a")
+
+        def fake_read() -> Dict[str, str]:
+            calls.append(("read gitlinks of", p_a.relpath))
+            return {"b": "beef1234"}
+
+        p_a.GetSubmoduleRevisions = mock.Mock(side_effect=fake_read)
+        p_a_b = FakeProject(
+            "a/b", parent=p_a, is_derived=True, gitlink_path="b"
+        )
+
+        def fake_fetch(
+            projects: List[FakeProject], *_args: object
+        ) -> sync._FetchResult:
+            calls.append(("fetch", [p.relpath for p in projects]))
+            return sync._FetchResult(True, {p.objdir for p in projects})
+
+        opt = mock.Mock(fail_fast=False)
+        with mock.patch.object(cmd, "_Fetch", side_effect=fake_fetch):
+            result = cmd._FetchParentFirst([p_a_b, p_a], opt, None, None, [])
+
+        self.assertTrue(result.success)
+        self.assertEqual(result.projects, {"a", "a/b"})
+        self.assertEqual(
+            calls,
+            [
+                ("fetch", ["a"]),
+                ("read gitlinks of", "a"),
+                ("fetch", ["a/b"]),
+            ],
+        )
+
+
+class WithoutProjects(unittest.TestCase):
+    def test_drops_the_unwanted_projects(self) -> None:
+        p_a = FakeProject("a")
+        p_a_b = FakeProject("a/b")
+        self.assertEqual(sync._WithoutProjects([p_a, p_a_b], [p_a_b]), [p_a])
+        self.assertEqual(sync._WithoutProjects([p_a, p_a_b], []), [p_a, p_a_b])
+
+    def test_keeps_projects_with_the_same_path(self) -> None:
+        # Paths are relative to their own (sub)manifest, so two projects can
+        # share one.
+        first = FakeProject("a/b")
+        second = FakeProject("a/b")
+        self.assertEqual(
+            sync._WithoutProjects([first, second], [second]), [first]
+        )
+
+
 class Chunksize(unittest.TestCase):
     """Tests for _chunksize."""
 
@@ -760,6 +990,42 @@ class CheckForBloatedProjects(unittest.TestCase):
         self.cmd.git_event_log = mock.MagicMock()
         self.cmd._bloated_projects = []
 
+    def test_one_project_reuses_status_head_oid(self) -> None:
+        """The bloat scan gets dirty state and HEAD from one snapshot."""
+        status = git_status.StatusSnapshot()
+        status.branch_oid = "local"
+        self.project._GetStatusSnapshot.return_value = status
+        self.project.GetRevisionId.return_value = "manifest"
+        self.project.bare_git.count_objects.return_value = (
+            "packs: 0\nsize-pack: 0\nsize-garbage: 0\n"
+        )
+        with mock.patch.object(
+            sync.Sync,
+            "get_parallel_context",
+            return_value={"projects": [self.project]},
+        ):
+            self.assertIsNone(self.cmd._CheckOneBloatedProject(0))
+
+        self.project.IsDirty.assert_not_called()
+        self.project.work_git.rev_parse.assert_not_called()
+        self.project.bare_git.count_objects.assert_called_once_with("-v")
+
+    def test_one_unborn_project_skips_bloat_check(self) -> None:
+        """A porcelain initial branch behaves like failed rev-parse HEAD."""
+        status = git_status.StatusSnapshot()
+        status.index_changes["staged"] = git_status.StatusEntry("staged", "M")
+        self.project._GetStatusSnapshot.return_value = status
+
+        with mock.patch.object(
+            sync.Sync,
+            "get_parallel_context",
+            return_value={"projects": [self.project]},
+        ):
+            self.assertIsNone(self.cmd._CheckOneBloatedProject(0))
+
+        self.project.GetRevisionId.assert_not_called()
+        self.project.bare_git.count_objects.assert_not_called()
+
     @mock.patch("subcmds.sync.git_require")
     def test_git_version_unsupported(self, mock_git_require):
         """Test that it returns early if git version is unsupported."""
@@ -902,7 +1168,10 @@ class SyncCommand(unittest.TestCase):
         self.project = p = mock.MagicMock(
             use_git_worktrees=False,
             UseAlternates=False,
+            UseReprojectCmd=False,
             name="project",
+            relpath="rel_path",
+            parent=None,
             Sync_NetworkHalf=Sync_NetworkHalf,
             Sync_LocalHalf=Sync_LocalHalf,
             RelPath=mock.Mock(return_value="rel_path"),
@@ -961,6 +1230,78 @@ class SyncCommand(unittest.TestCase):
         _, kwargs = self.cmd.GetProjects.call_args
         self.assertEqual(kwargs.get("groups"), "my_group")
 
+    def _ExecuteUntilSync(
+        self, args: List[str]
+    ) -> Tuple[mock.MagicMock, mock.MagicMock]:
+        """Run Execute up to the sync itself, returning the sync mocks."""
+        self.opt.mp_update = False
+        with contextlib.ExitStack() as stack:
+            for name in (
+                "_UpdateRepoProject",
+                "_UpdateProjectsRevisionId",
+                "_ValidateOptionsWithManifest",
+                "_RunPostSyncHook",
+            ):
+                stack.enter_context(mock.patch.object(self.cmd, name))
+            phased = stack.enter_context(
+                mock.patch.object(self.cmd, "_SyncPhased")
+            )
+            interleaved = stack.enter_context(
+                mock.patch.object(self.cmd, "_SyncInterleaved")
+            )
+            self.cmd.Execute(self.opt, args)
+        return phased, interleaved
+
+    def test_reproject_cmd_allows_a_flat_manifest(self) -> None:
+        """Ensure repo.reprojectcmd syncs a manifest without nesting."""
+        self.project.UseReprojectCmd = True
+        phased, interleaved = self._ExecuteUntilSync([])
+        self.assertTrue(phased.called or interleaved.called)
+
+    def test_reproject_cmd_rejects_nested_projects(self) -> None:
+        """Ensure repo.reprojectcmd fails a manifest with nested projects."""
+        p_foo = FakeProject("foo")
+        p_foo_bar = FakeProject("foo/bar")
+        p_foo.UseReprojectCmd = p_foo_bar.UseReprojectCmd = True
+        self.cmd.GetProjects.return_value = [p_foo, p_foo_bar]
+        with self.assertRaises(sync.SyncError) as e:
+            self._ExecuteUntilSync([])
+        self.assertIn("foo/bar", str(e.exception))
+        self.assertNotIn(" - foo\n", str(e.exception))
+
+    def test_reproject_cmd_rejects_a_submodule(self) -> None:
+        """Ensure repo.reprojectcmd fails a manifest with a submodule."""
+        p_foo = FakeProject("foo")
+        p_sub = FakeProject("foo/sub", parent=p_foo, is_derived=True)
+        p_foo.UseReprojectCmd = p_sub.UseReprojectCmd = True
+        self.cmd.GetProjects.return_value = [p_foo, p_sub]
+        with self.assertRaises(sync.SyncError) as e:
+            self._ExecuteUntilSync([])
+        self.assertIn("foo/sub", str(e.exception))
+
+    def test_reproject_cmd_checks_the_whole_manifest(self) -> None:
+        """Ensure nesting is checked beyond the projects given as args."""
+        p_foo = FakeProject("foo")
+        p_foo_bar = FakeProject("foo/bar")
+        p_foo.UseReprojectCmd = p_foo_bar.UseReprojectCmd = True
+        self.cmd.GetProjects.side_effect = lambda args, **kwargs: (
+            [p_foo_bar] if args else [p_foo, p_foo_bar]
+        )
+        with self.assertRaises(sync.SyncError):
+            self._ExecuteUntilSync(["foo/bar"])
+        self.assertEqual(self.cmd.GetProjects.call_count, 2)
+        _, kwargs = self.cmd.GetProjects.call_args
+        self.assertEqual(kwargs.get("missing_ok"), True)
+
+    def test_reproject_cmd_off_ignores_nested_projects(self) -> None:
+        """Ensure nesting is only checked with repo.reprojectcmd in use."""
+        projects = [FakeProject("foo"), FakeProject("foo/bar")]
+        for p in projects:
+            p.Exists = False
+        self.cmd.GetProjects.return_value = projects
+        phased, interleaved = self._ExecuteUntilSync([])
+        self.assertTrue(phased.called or interleaved.called)
+
 
 class SyncUpdateRepoProject(unittest.TestCase):
     """Tests for Sync._UpdateRepoProject."""
@@ -1158,6 +1499,203 @@ class InterleavedSyncTest(unittest.TestCase):
 
         execute_mock.assert_called_once()
 
+    def test_interleaved_refreshes_submodule_revision(self) -> None:
+        """Test submodules are synced at the revision of the fetched parent."""
+        opt, args = self.cmd.OptionParser.parse_args(["--interleaved", "-j4"])
+        opt.quiet = True
+
+        submodule = FakeProject(
+            "projA/sub",
+            name="projA_sub",
+            objdir="objA_sub",
+            parent=self.projA,
+            is_derived=True,
+            revisionId="stale",
+            gitlink_path="sub",
+        )
+        all_projects = [self.projA, submodule]
+        mock.patch.object(
+            self.cmd, "GetProjects", return_value=all_projects
+        ).start()
+
+        self.projA.GetSubmoduleRevisions = mock.Mock(
+            return_value={"sub": "fetched"}
+        )
+
+        synced = []
+
+        def execute_side_effect(
+            jobs: int,
+            target: object,
+            work_items: List[List[int]],
+            **kwargs: object,
+        ) -> bool:
+            synced_relpaths_set = kwargs["callback"].args[0]
+            projects_in_pass = self.cmd.get_parallel_context()["projects"]
+            for item in work_items:
+                for project_idx in item:
+                    project = projects_in_pass[project_idx]
+                    synced.append((project.relpath, project.revisionId))
+                    synced_relpaths_set.add(project.relpath)
+            return True
+
+        mock.patch.object(
+            self.cmd, "ExecuteInParallel", side_effect=execute_side_effect
+        ).start()
+
+        self.cmd._SyncInterleaved(
+            opt,
+            args,
+            [],
+            self.manifest,
+            self.manifest.manifestProject,
+            all_projects,
+            {},
+        )
+
+        self.assertIn(("projA/sub", "fetched"), synced)
+
+    def test_interleaved_skips_removed_submodule(self) -> None:
+        """Test submodules dropped by their parent are not checked out."""
+        opt, args = self.cmd.OptionParser.parse_args(["--interleaved", "-j4"])
+        opt.quiet = True
+
+        submodule = FakeProject(
+            "projA/sub",
+            name="projA_sub",
+            objdir="objA_sub",
+            parent=self.projA,
+            is_derived=True,
+            revisionId="stale",
+            gitlink_path="sub",
+        )
+        # The parent no longer holds a gitlink for the submodule.
+        self.projA.GetSubmoduleRevisions = mock.Mock(return_value={})
+        # The reloaded manifest no longer derives the removed submodule.
+        mock.patch.object(
+            self.cmd, "GetProjects", return_value=[self.projA]
+        ).start()
+
+        synced = []
+
+        def execute_side_effect(
+            jobs: int,
+            target: object,
+            work_items: List[List[int]],
+            **kwargs: object,
+        ) -> bool:
+            synced_relpaths_set = kwargs["callback"].args[0]
+            projects_in_pass = self.cmd.get_parallel_context()["projects"]
+            for item in work_items:
+                for project_idx in item:
+                    project = projects_in_pass[project_idx]
+                    synced.append(project.relpath)
+                    synced_relpaths_set.add(project.relpath)
+            return True
+
+        mock.patch.object(
+            self.cmd, "ExecuteInParallel", side_effect=execute_side_effect
+        ).start()
+
+        self.cmd._SyncInterleaved(
+            opt,
+            args,
+            [],
+            self.manifest,
+            self.manifest.manifestProject,
+            [self.projA, submodule],
+            {},
+        )
+
+        self.assertEqual(synced, ["projA"])
+
+    def _make_syncable(self, project: FakeProject) -> FakeProject:
+        project.Sync_NetworkHalf = mock.Mock(
+            return_value=SyncNetworkHalfResult(error=None, remote_fetched=True)
+        )
+        project.Sync_LocalHalf = mock.Mock()
+        return project
+
+    def _run_interleaved(
+        self,
+        opt: optparse.Values,
+        initial_projects: List[FakeProject],
+        reloaded_projects: List[FakeProject],
+    ) -> None:
+        """Run _SyncInterleaved with the real workers and callback.
+
+        |initial_projects| make up the first pass, |reloaded_projects| every
+        later one, the way reloading the manifest between passes does.
+        """
+        mock.patch.object(
+            self.cmd, "GetProjects", return_value=reloaded_projects
+        ).start()
+        mock.patch.object(self.cmd, "event_log").start()
+
+        def execute_side_effect(
+            jobs: int,
+            target: object,
+            work_items: List[List[int]],
+            **kwargs: object,
+        ) -> bool:
+            results = [target(item) for item in work_items]
+            return kwargs["callback"](None, kwargs["output"], results)
+
+        mock.patch.object(
+            self.cmd, "ExecuteInParallel", side_effect=execute_side_effect
+        ).start()
+
+        with mock.patch("subcmds.sync.SyncBuffer") as mock_sync_buffer:
+            mock_sync_buffer.return_value.Finish.return_value = True
+            mock_sync_buffer.return_value.errors = []
+            self.cmd._SyncInterleaved(
+                opt,
+                [],
+                [],
+                self.manifest,
+                self.manifest.manifestProject,
+                initial_projects,
+                {},
+            )
+
+    def test_interleaved_syncs_same_path_projects_of_every_manifest(
+        self,
+    ) -> None:
+        """Test a project is not skipped because another shares its path."""
+        opt = self._get_opts(["--interleaved", "-j4"])
+        outer = self._make_syncable(
+            FakeProject("foo", name="outer", objdir="a")
+        )
+        sub = self._make_syncable(
+            FakeProject("foo", name="sub", objdir="b", path_prefix="sub")
+        )
+
+        # |sub| is only discovered once the manifest is reloaded after the
+        # first pass has synced |outer|.
+        self._run_interleaved(opt, [outer], [outer, sub])
+
+        outer.Sync_LocalHalf.assert_called_once()
+        sub.Sync_LocalHalf.assert_called_once()
+
+    def test_interleaved_reports_failures_by_a_unique_path(self) -> None:
+        """Test failing projects are listed by a path that is theirs alone."""
+        opt = self._get_opts(["--interleaved", "-j4"])
+        outer = self._make_syncable(
+            FakeProject("foo", name="outer", objdir="a")
+        )
+        sub = self._make_syncable(
+            FakeProject("foo", name="sub", objdir="b", path_prefix="sub")
+        )
+        sub.Sync_LocalHalf.side_effect = GitError("checkout failed")
+        self.cmd.git_event_log = mock.MagicMock()
+
+        with self.assertRaises(sync.SyncError):
+            self._run_interleaved(opt, [outer, sub], [outer, sub])
+
+        self.assertEqual(
+            self.cmd._interleaved_err_checkout_results, ["sub/foo"]
+        )
+
     def test_interleaved_shared_objdir_serial(self):
         """Test that projects with shared objdir are processed serially."""
         opt, args = self.cmd.OptionParser.parse_args(["--interleaved", "-j4"])
@@ -1252,6 +1790,23 @@ class InterleavedSyncTest(unittest.TestCase):
             project.Sync_NetworkHalf.assert_called_once()
             project.Sync_LocalHalf.assert_called_once()
 
+    def test_worker_reports_a_path_unique_across_manifests(self) -> None:
+        """Test _SyncResult.relpath tells apart same-path projects."""
+        project = FakeProject("foo", objdir="objA", path_prefix="sub")
+        self._make_syncable(project)
+        self.mock_context["projects"] = [project]
+
+        for this_manifest_only, expected in ((False, "sub/foo"), (True, "foo")):
+            with self.subTest(this_manifest_only=this_manifest_only):
+                opt = self._get_opts()
+                opt.this_manifest_only = this_manifest_only
+                with mock.patch("subcmds.sync.SyncBuffer") as mock_sync_buffer:
+                    mock_sync_buffer.return_value.Finish.return_value = True
+                    mock_sync_buffer.return_value.errors = []
+                    result_obj = self.cmd._SyncProjectList(opt, [0])
+
+                self.assertEqual(result_obj.results[0].relpath, expected)
+
     def test_worker_fetch_fails(self):
         """Test _SyncProjectList with a failed fetch."""
         opt = self._get_opts()

tests/test_subcmds_upload.py

@@ -14,6 +14,7 @@
 
 """Unittests for the subcmds/upload.py module."""
 
+from typing import List, Optional
 from unittest import mock
 
 import pytest
@@ -63,3 +64,172 @@ def test_UploadAndReport_UnhandledError(cmd: upload.Upload) -> None:
     with mock.patch.object(cmd, "_UploadBranch", side_effect=UnexpectedError):
         with pytest.raises(UnexpectedError):
             cmd._UploadAndReport(opt, [mock.MagicMock()], _STUB_PEOPLE)
+
+
+def test_GetMergeBranch_explicit_branch(cmd: upload.Upload) -> None:
+    """Verify _GetMergeBranch reads branch.merge for explicit local_branch."""
+    mock_project = mock.MagicMock()
+    mock_branch = mock.MagicMock()
+    mock_branch.merge = "refs/heads/main"
+    mock_project.GetBranch.return_value = mock_branch
+
+    res = cmd._GetMergeBranch(mock_project, local_branch="feature")
+    assert res == "refs/heads/main"
+    mock_project.GetBranch.assert_called_once_with("feature")
+
+
+def test_GetMergeBranch_current_branch(cmd: upload.Upload) -> None:
+    """Verify _GetMergeBranch falls back to project.CurrentBranch."""
+    mock_project = mock.MagicMock()
+    mock_project.CurrentBranch = "auto-cbr"
+    mock_branch = mock.MagicMock()
+    mock_branch.merge = "refs/heads/upstream-main"
+    mock_project.GetBranch.return_value = mock_branch
+
+    res = cmd._GetMergeBranch(mock_project, local_branch=None)
+    assert res == "refs/heads/upstream-main"
+    mock_project.GetBranch.assert_called_once_with("auto-cbr")
+
+
+def test_GetMergeBranch_none_when_no_branch(cmd: upload.Upload) -> None:
+    """Verify _GetMergeBranch returns empty string when detached HEAD."""
+    mock_project = mock.MagicMock()
+    mock_project.CurrentBranch = None
+
+    res = cmd._GetMergeBranch(mock_project, local_branch=None)
+    assert res == ""
+
+
+def test_GatherOne_returns_resolved_current_branch(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Upload error reporting reuses the branch gathered by the worker."""
+    project = mock.MagicMock()
+    project.CurrentBranch = "topic"
+    branch = mock.sentinel.branch
+    project.GetUploadableBranch.return_value = branch
+    monkeypatch.setattr(
+        upload.Upload,
+        "get_parallel_context",
+        lambda: {"projects": [project]},
+    )
+    opt = mock.MagicMock(current_branch=True)
+
+    assert upload.Upload._GatherOne(opt, 0) == (0, [branch], "topic")
+
+    project.GetUploadableBranch.assert_called_once_with("topic")
+
+
+def _create_mock_branch(
+    name: str = "main",
+    commits: Optional[List[str]] = None,
+    project_relpath: str = "project-a",
+) -> mock.MagicMock:
+    """Helper to construct a mock ReviewableBranch."""
+    branch = mock.MagicMock()
+    branch.name = name
+    branch.commits = commits if commits is not None else ["commit1"]
+
+    project = mock.MagicMock()
+    project.RelPath.return_value = project_relpath
+    branch.project = project
+    return branch
+
+
+def test_MultipleBranches_yes_with_current_branch_flag_bypasses_editor(
+    cmd: upload.Upload,
+) -> None:
+    """_MultipleBranches with --yes and -c flag bypasses editor."""
+    opt, _ = cmd.OptionParser.parse_args(["-c", "-y"])
+    branch1 = _create_mock_branch("b1", project_relpath="p1")
+    branch2 = _create_mock_branch("b2", project_relpath="p2")
+    pending = [(branch1.project, [branch1]), (branch2.project, [branch2])]
+
+    with mock.patch.object(cmd, "_UploadAndReport") as mock_upload, mock.patch(
+        "editor.Editor.EditString"
+    ) as mock_edit:
+        cmd._MultipleBranches(opt, pending, _STUB_PEOPLE)
+        mock_edit.assert_not_called()
+        mock_upload.assert_called_once_with(
+            opt, [branch1, branch2], _STUB_PEOPLE
+        )
+
+
+def test_MultipleBranches_yes_with_cbr_flag_bypasses_editor(
+    cmd: upload.Upload,
+) -> None:
+    """_MultipleBranches with --yes and --cbr flag bypasses editor."""
+    opt, _ = cmd.OptionParser.parse_args(["--cbr", "--yes"])
+    branch1 = _create_mock_branch("b1", project_relpath="p1")
+    branch2 = _create_mock_branch("b2", project_relpath="p2")
+    pending = [(branch1.project, [branch1]), (branch2.project, [branch2])]
+
+    with mock.patch.object(cmd, "_UploadAndReport") as mock_upload, mock.patch(
+        "editor.Editor.EditString"
+    ) as mock_edit:
+        cmd._MultipleBranches(opt, pending, _STUB_PEOPLE)
+        mock_edit.assert_not_called()
+        mock_upload.assert_called_once_with(
+            opt, [branch1, branch2], _STUB_PEOPLE
+        )
+
+
+def test_MultipleBranches_yes_with_branch_flag_bypasses_editor(
+    cmd: upload.Upload,
+) -> None:
+    """_MultipleBranches with --yes and --br flag bypasses editor."""
+    opt, _ = cmd.OptionParser.parse_args(["--br", "feature", "-y"])
+    branch1 = _create_mock_branch("feature", project_relpath="p1")
+    branch2 = _create_mock_branch("feature", project_relpath="p2")
+    pending = [(branch1.project, [branch1]), (branch2.project, [branch2])]
+
+    with mock.patch.object(cmd, "_UploadAndReport") as mock_upload, mock.patch(
+        "editor.Editor.EditString"
+    ) as mock_edit:
+        cmd._MultipleBranches(opt, pending, _STUB_PEOPLE)
+        mock_edit.assert_not_called()
+        mock_upload.assert_called_once_with(
+            opt, [branch1, branch2], _STUB_PEOPLE
+        )
+
+
+def test_MultipleBranches_yes_with_branch_flag_empty_pending_dies(
+    cmd: upload.Upload,
+) -> None:
+    """_MultipleBranches with --yes and empty pending branches dies."""
+    opt, _ = cmd.OptionParser.parse_args(["--br", "feature", "-y"])
+    mock_project = mock.MagicMock()
+    pending = [(mock_project, [])]
+
+    with pytest.raises(
+        upload.UploadExitError, match="nothing ready for upload"
+    ):
+        cmd._MultipleBranches(opt, pending, _STUB_PEOPLE)
+
+
+def test_MultipleBranches_yes_without_branch_or_cbr_uses_editor(
+    cmd: upload.Upload,
+) -> None:
+    """_MultipleBranches with -y but no -c/--br falls back to editor."""
+    opt, _ = cmd.OptionParser.parse_args(["-y"])
+    branch1 = _create_mock_branch("b1", project_relpath="p1")
+    branch1.date = "2026-08-26"
+    mock_remote = mock.MagicMock()
+    branch1.project.dest_branch = None
+    branch1.project.revisionExpr = "refs/heads/main"
+    branch_config = mock.MagicMock()
+    branch_config.remote = mock_remote
+    branch1.project.GetBranch.return_value = branch_config
+    pending = [(branch1.project, [branch1])]
+
+    edited_script = (
+        "project p1/:\n"
+        "  branch b1 ( 1 commit, 2026-08-26) to remote branch "
+        "refs/heads/main:\n"
+    )
+    with mock.patch.object(cmd, "_UploadAndReport") as mock_upload, mock.patch(
+        "editor.Editor.EditString", return_value=edited_script
+    ) as mock_edit:
+        cmd._MultipleBranches(opt, pending, _STUB_PEOPLE)
+        mock_edit.assert_called_once()
+        mock_upload.assert_called_once_with(opt, [branch1], _STUB_PEOPLE)

tests/test_subcmds_version.py

@@ -0,0 +1,52 @@
+# Copyright (C) 2026 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for subcmds/version.py."""
+
+from unittest import mock
+
+import pytest
+
+from subcmds import version
+
+
+def test_repo_version_uses_one_pretty_format_call(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    project = mock.MagicMock()
+    project.bare_git.log.return_value = "v2.0-1-g12345678\nTue, 25 Aug\n"
+    monkeypatch.setattr(version, "git_require", lambda _version: True)
+
+    result = version.Version._RepoVersion(project)
+
+    assert result == ("v2.0-1-g12345678", "Tue, 25 Aug")
+    project.bare_git.log.assert_called_once_with(
+        "-1", "--format=%(describe)%n%cD", "HEAD"
+    )
+    project.bare_git.describe.assert_not_called()
+
+
+def test_repo_version_keeps_old_git_fallback(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    project = mock.MagicMock()
+    project.bare_git.describe.return_value = "v2.0"
+    project.bare_git.log.return_value = "Tue, 25 Aug"
+    monkeypatch.setattr(version, "git_require", lambda _version: False)
+
+    result = version.Version._RepoVersion(project)
+
+    assert result == ("v2.0", "Tue, 25 Aug")
+    project.bare_git.describe.assert_called_once_with("HEAD")
+    project.bare_git.log.assert_called_once_with("-1", "--format=%cD", "HEAD")