diff --git a/tests/e2e/README.md b/tests/e2e/README.md
index 075699a61..201a05a3b 100644
--- a/tests/e2e/README.md
+++ b/tests/e2e/README.md
@@ -23,3 +23,10 @@ They run as part of `./run_tests` by default, after the unit tests.
 The suite is skipped automatically when `git http-backend` isn't
 available, when git is older than 2.28 (need default branch support and
 superproject support), or when not run from a git checkout.
+
+## Layout
+
+* `harness.py`: the git server, server-side repos & the repo client.
+* `test_init_sync.py`: core `repo init` & `repo sync` options.
+* `test_workflows.py`: multi-step workflows.
+* `test_manifest_regressions.py`: manifests that broke users in the past.
diff --git a/tests/e2e/harness.py b/tests/e2e/harness.py
index 0cd1d319a..29a162a57 100644
--- a/tests/e2e/harness.py
+++ b/tests/e2e/harness.py
@@ -49,6 +49,7 @@ from typing import (
     Mapping,
     NamedTuple,
     Optional,
+    Set,
     Tuple,
     Union,
 )
@@ -934,6 +935,24 @@ class RepoClient:
         """Return the commit checked out in `path`."""
         return self.git(path, "rev-parse", "HEAD")
 
+    def remote_branches(self, path: str) -> Set[str]:
+        """Return the names of the `origin` remote-tracking branches."""
+        out = self.git(
+            path,
+            "for-each-ref",
+            "--format=%(refname:lstrip=3)",
+            "refs/remotes/origin/",
+        )
+        return set(out.split())
+
+    def checkouts(self) -> Set[str]:
+        """Return the names of the top-level dirs, except `.repo`."""
+        return {
+            x.name
+            for x in self.top.iterdir()
+            if x.is_dir() and x.name != ".repo"
+        }
+
     def has_object(self, path: str, oid: str) -> bool:
         """Whether the checkout at `path` has object `oid` locally."""
         # Unlike `cat-file -e`, this never lazily fetches missing objects in
diff --git a/tests/e2e/test_init_sync.py b/tests/e2e/test_init_sync.py
new file mode 100644
index 000000000..5fb1db100
--- /dev/null
+++ b/tests/e2e/test_init_sync.py
@@ -0,0 +1,227 @@
+# 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.
+
+"""E2E tests for the core `repo init` & `repo sync` options."""
+
+from typing import List, Set
+
+from harness import GIT_DEFAULTS_PARAMS
+from harness import GitHost
+from harness import manifest_xml
+from harness import RepoClient
+import pytest
+
+
+@pytest.mark.parametrize("git_defaults", GIT_DEFAULTS_PARAMS)
+def test_init_sync_basic(host: GitHost, client: RepoClient) -> None:
+    """The basic `repo init && repo sync` flow."""
+    foo = host.create_repo("platform/foo", {"foo.txt": "foo"})
+    host.create_repo("platform/bar", {"bar.txt": "bar"})
+    host.create_manifest(
+        manifest_xml(
+            '<project name="platform/foo" path="foo" />',
+            '<project name="platform/bar" path="sub/bar" />',
+        )
+    )
+
+    client.init(host.manifest_url)
+    client.sync()
+
+    assert (client.top / "foo" / "foo.txt").read_text() == "foo"
+    assert (client.top / "sub" / "bar" / "bar.txt").read_text() == "bar"
+    assert client.head("foo") == foo.rev_parse("main")
+    assert client.list_projects() == {
+        "foo": "platform/foo",
+        "sub/bar": "platform/bar",
+    }
+    # The code under test is what got installed & is running.
+    assert "v99.0-e2e" in client.run("version").stdout
+
+
+@pytest.mark.parametrize(
+    "init_args,sync_args,manifest_refs,project_refs",
+    [
+        # `init -c` is the default for the manifest project.
+        ([], [], {"main"}, {"main", "other"}),
+        (["--no-current-branch"], [], {"main", "other"}, {"main", "other"}),
+        ([], ["-c"], {"main"}, {"main"}),
+    ],
+)
+def test_current_branch(
+    host: GitHost,
+    client: RepoClient,
+    init_args: List[str],
+    sync_args: List[str],
+    manifest_refs: Set[str],
+    project_refs: Set[str],
+) -> None:
+    """`init` limits the manifest fetch; `sync -c` limits projects."""
+    foo = host.create_repo("platform/foo", {"foo.txt": "main"})
+    foo.commit({"foo.txt": "other"}, branch="other")
+    manifest = host.create_manifest(
+        manifest_xml('<project name="platform/foo" />')
+    )
+    manifest.commit({"README": "other"}, branch="other")
+
+    client.init(host.manifest_url, *init_args)
+    assert client.remote_branches(".repo/manifests") == manifest_refs
+
+    client.sync(*sync_args)
+    assert client.remote_branches("platform/foo") == project_refs
+    assert (client.top / "platform/foo/foo.txt").read_text() == "main"
+
+
+@pytest.mark.parametrize(
+    "sync_args,expect_bundle", [([], True), (["--no-clone-bundle"], False)]
+)
+def test_clone_bundle(
+    host: GitHost,
+    client: RepoClient,
+    sync_args: List[str],
+    expect_bundle: bool,
+) -> None:
+    """repo bootstraps new projects from clone.bundle when available."""
+    foo = host.create_repo("platform/foo", {"foo.txt": "foo"})
+    # A commit that only the bundle has, to prove the bundle was applied.
+    bundle_only = foo.commit({"x": "bundle"}, branch="bundle-only")
+    foo.write_bundle()
+    foo.git("update-ref", "-d", "refs/heads/bundle-only")
+    host.create_manifest(manifest_xml('<project name="platform/foo" />'))
+
+    client.init(host.manifest_url)
+    client.sync(*sync_args)
+
+    bundle_gets = [
+        r
+        for r in host.requests()
+        if r.path.endswith("/platform/foo/clone.bundle")
+    ]
+    assert [r.status for r in bundle_gets] == ([200] if expect_bundle else [])
+    assert client.has_object("platform/foo", bundle_only) == expect_bundle
+    assert client.head("platform/foo") == foo.rev_parse("main")
+
+
+@pytest.mark.parametrize(
+    "init_args,project_attrs",
+    [
+        (["--depth=1"], ""),
+        ([], 'clone-depth="1"'),
+    ],
+)
+def test_shallow(
+    host: GitHost,
+    client: RepoClient,
+    init_args: List[str],
+    project_attrs: str,
+) -> None:
+    """Shallow clones via `--depth` and manifest `clone-depth`."""
+    foo = host.create_repo("platform/foo", {"foo.txt": "1"})
+    foo.commit({"foo.txt": "2"})
+    foo.commit({"foo.txt": "3"})
+    host.create_manifest(
+        manifest_xml(f'<project name="platform/foo" {project_attrs} />')
+    )
+
+    client.init(host.manifest_url, *init_args)
+    client.sync()
+
+    path = "platform/foo"
+    assert client.is_shallow(path)
+    assert client.git(path, "rev-list", "--count", "HEAD") == "1"
+    assert (client.top / path / "foo.txt").read_text() == "3"
+
+
+@pytest.mark.parametrize(
+    "init_args,expected",
+    [
+        ([], {"a", "b"}),
+        (["-g", "all"], {"a", "b", "c", "d"}),
+        (["-g", "g2"], {"c"}),
+        (["-g", "default,-g1"], {"a"}),
+        (["-g", "default,g2"], {"a", "b", "c"}),
+        (["-g", "name:platform/d"], {"d"}),
+    ],
+)
+def test_groups(
+    host: GitHost, client: RepoClient, init_args: List[str], expected: Set[str]
+) -> None:
+    """Manifest groups select which projects get synced."""
+    for name in "abcd":
+        host.create_repo(f"platform/{name}", {"f": name})
+    host.create_manifest(
+        manifest_xml(
+            '<project name="platform/a" path="a" />',
+            '<project name="platform/b" path="b" groups="g1" />',
+            '<project name="platform/c" path="c" groups="g2,notdefault" />',
+            '<project name="platform/d" path="d" groups="notdefault" />',
+        )
+    )
+
+    client.init(host.manifest_url, *init_args)
+    client.sync()
+
+    assert set(client.list_projects()) == expected
+    assert client.checkouts() == expected
+
+
+def test_local_manifests(host: GitHost, client: RepoClient) -> None:
+    """.repo/local_manifests/ can add, remove & extend projects."""
+    foo = host.create_repo("platform/foo", {"f": "main"})
+    stable = foo.commit({"f": "stable"}, branch="stable")
+    host.create_repo("platform/bar", {"f": "bar"})
+    host.create_repo("vendor/extra", {"f": "extra"})
+    host.create_manifest(
+        manifest_xml(
+            '<project name="platform/foo" path="foo" />',
+            '<project name="platform/bar" path="bar" />',
+        )
+    )
+    client.init(host.manifest_url)
+    local = client.repodir / "local_manifests"
+    local.mkdir()
+    (local / "local.xml").write_text(
+        """<?xml version="1.0" encoding="UTF-8"?>
+<manifest>
+  <remove-project name="platform/bar" />
+  <extend-project name="platform/foo" revision="stable" />
+  <project name="vendor/extra" path="extra" />
+</manifest>
+"""
+    )
+
+    client.sync()
+
+    assert client.list_projects() == {
+        "extra": "vendor/extra",
+        "foo": "platform/foo",
+    }
+    assert client.head("foo") == stable
+    assert not (client.top / "bar").exists()
+
+
+def test_manifest_name(host: GitHost, client: RepoClient) -> None:
+    """`-m` selects a manifest file other than default.xml."""
+    host.create_repo("platform/foo", {"f": "foo"})
+    host.create_repo("platform/bar", {"f": "bar"})
+    host.create_manifest(
+        {
+            "default.xml": manifest_xml('<project name="platform/foo" />'),
+            "other.xml": manifest_xml('<project name="platform/bar" />'),
+        }
+    )
+
+    client.init(host.manifest_url, "-m", "other.xml")
+    client.sync()
+
+    assert client.list_projects() == {"platform/bar": "platform/bar"}
diff --git a/tests/e2e/test_manifest_regressions.py b/tests/e2e/test_manifest_regressions.py
new file mode 100644
index 000000000..dfc3ff506
--- /dev/null
+++ b/tests/e2e/test_manifest_regressions.py
@@ -0,0 +1,387 @@
+# 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.
+
+"""E2E regression tests for manifests that broke users in the past.
+
+Each test names the commit and/or bug that fixed the original breakage.
+"""
+
+import os
+from typing import List
+
+from harness import GitHost
+from harness import Gitlink
+from harness import manifest_xml
+from harness import RepoClient
+import pytest
+
+
+def test_empty_manifest(host: GitHost, client: RepoClient) -> None:
+    """A manifest without projects syncs (616e314, b/377546300)."""
+    host.create_manifest(manifest_xml())
+
+    client.init(host.manifest_url)
+    client.sync()
+
+    assert client.list_projects() == {}
+
+
+def test_local_extend_project_with_superproject(
+    host: GitHost, client: RepoClient
+) -> None:
+    """Local `extend-project` works with superproject overrides.
+
+    Regression test for 3c0e67b (b/470374343).
+    """
+    foo = host.create_repo("platform/foo", {"f": "v1"})
+    pinned = foo.rev_parse("main")
+    host.create_repo("superproject", {"foo": Gitlink(pinned)})
+    foo.commit({"f": "v2"})
+    host.create_manifest(
+        manifest_xml(
+            '<superproject name="superproject" />',
+            '<project name="platform/foo" path="foo" />',
+        )
+    )
+    client.init(host.manifest_url, "--use-superproject")
+    local = client.repodir / "local_manifests"
+    local.mkdir()
+    (local / "local.xml").write_text(
+        "<manifest>\n"
+        '  <extend-project name="platform/foo" groups="extra" />\n'
+        "</manifest>\n"
+    )
+
+    client.sync("--use-superproject")
+
+    assert client.head("foo") == pinned
+
+
+# 3af9e2f fixed both the regular & the --optimized-fetch skip-fetch checks.
+@pytest.mark.parametrize("sync_args", [[], ["--optimized-fetch"]])
+def test_same_project_shallow_pinned_paths(
+    host: GitHost, client: RepoClient, sync_args: List[str]
+) -> None:
+    """One project at two paths pinned to SHAs with sync-c, one shallow.
+
+    The non-shallow path shares the shallow path's (depth-limited) object
+    store, so its fetch must not be skipped as already up to date, or its
+    history is left truncated.
+
+    Regression test for 3af9e2f (b/505072873).
+    """
+    foo = host.create_repo("platform/foo", {"f": "1"})
+    host.create_manifest(manifest_xml())
+
+    def pin(rev: str) -> None:
+        host.update_manifest(
+            manifest_xml(
+                f'<project name="platform/foo" path="a" revision="{rev}" '
+                'clone-depth="1" />',
+                f'<project name="platform/foo" path="b" revision="{rev}" />',
+                default='remote="origin" revision="main" sync-c="true"',
+            )
+        )
+
+    pin(foo.commit({"f": "2"}))
+    client.init(host.manifest_url)
+    client.sync(*sync_args)
+
+    # Skip a commit so the shallow fetch alone would leave a gap in the shared
+    # history.
+    foo.commit({"f": "3"})
+    latest = foo.commit({"f": "4"})
+    pin(latest)
+    client.sync(*sync_args)
+
+    assert client.is_shallow("a")
+    for path in ("a", "b"):
+        assert client.head(path) == latest
+        # Fails to traverse the shared, truncated history if `path`'s fetch
+        # was skipped.
+        client.git(path, "rev-list", "HEAD")
+
+
+def test_shallow_pinned_with_upstream(
+    host: GitHost, client: RepoClient
+) -> None:
+    """clone-depth + upstream + SHA revisions stay shallow.
+
+    The bug only triggered when the upstream branch was ahead of the pinned
+    SHA, so each pin leaves `main` one commit ahead.
+
+    Regression test for d9cc0a1 (b/427093249).
+    """
+    foo = host.create_repo("platform/foo", {"f": "1"})
+    host.create_manifest(manifest_xml())
+
+    def pin(rev: str) -> None:
+        host.update_manifest(
+            manifest_xml(
+                f'<project name="platform/foo" revision="{rev}" '
+                'upstream="main" clone-depth="1" />'
+            )
+        )
+
+    path = "platform/foo"
+    pinned = foo.commit({"f": "2"})
+    foo.commit({"f": "2 ahead"})
+    pin(pinned)
+    client.init(host.manifest_url)
+    client.sync()
+    assert client.head(path) == pinned
+    assert client.git(path, "rev-list", "--count", "HEAD") == "1"
+
+    pinned = foo.commit({"f": "3"})
+    foo.commit({"f": "3 ahead"})
+    pin(pinned)
+    client.sync()
+
+    assert client.head(path) == pinned
+    assert client.git(path, "rev-list", "--count", "HEAD") == "1"
+
+
+def test_pinned_revision_refreshes_upstream(
+    host: GitHost, client: RepoClient
+) -> None:
+    """Pinned SHAs already present locally still refresh the upstream ref.
+
+    Regression test for d27d682: when the pinned commit was already in the
+    local object store (e.g. prefetched), `sync -c` skipped the fetch as an
+    immutable revision, so the stale tracking ref of the upstream branch was
+    never updated.
+    """
+    foo = host.create_repo("platform/foo", {"f": "1"})
+    host.create_manifest(manifest_xml())
+
+    def pin(rev: str) -> None:
+        host.update_manifest(
+            manifest_xml(
+                f'<project name="platform/foo" revision="{rev}" '
+                'upstream="main" />',
+                # The skip only happens when fetching the current branch only.
+                default='remote="origin" revision="main" sync-c="true"',
+            )
+        )
+
+    initial = foo.rev_parse("main")
+    pin(initial)
+    client.init(host.manifest_url)
+    client.sync()
+
+    path = "platform/foo"
+    second = foo.commit({"f": "2"})
+    latest = foo.commit({"f": "3"})
+    # Emulate a background prefetch that doesn't touch the tracking refs.
+    client.git(
+        path, "fetch", "-q", "--refmap=", "origin", "+main:refs/prefetch/main"
+    )
+    assert client.has_object(path, second)
+    assert client.git(path, "rev-parse", "refs/remotes/origin/main") == initial
+    pin(second)
+    client.sync()
+
+    assert client.head(path) == second
+    assert client.git(path, "rev-parse", "refs/remotes/origin/main") == latest
+
+
+def test_nested_projects(host: GitHost, client: RepoClient) -> None:
+    """Nested project paths are checked out and removed in the right order.
+
+    Regression test for 4679022 (b/325119758).
+    """
+    foo = host.create_repo("platform/foo", {"f": "foo", "bar/f": "old"})
+    host.create_repo("platform/bar", {"f": "foo/bar"})
+    host.create_repo("platform/foo-bar", {"f": "foo-bar"})
+    # aaa shares foo/bar's project, so foo/bar is grouped with it & checked out
+    # early unless the checkout order puts it after its parent foo.
+    host.create_manifest(
+        manifest_xml(
+            '<project name="platform/bar" path="aaa" />',
+            '<project name="platform/foo" path="foo" />',
+            '<project name="platform/foo-bar" path="foo-bar" />',
+        )
+    )
+    client.init(host.manifest_url)
+    client.sync()
+
+    # Move foo's bar/f into the new nested project foo/bar.
+    foo.commit({"bar/f": None})
+    host.update_manifest(
+        manifest_xml(
+            '<project name="platform/bar" path="aaa" />',
+            '<project name="platform/foo" path="foo" />',
+            '<project name="platform/bar" path="foo/bar" />',
+            '<project name="platform/foo-bar" path="foo-bar" />',
+        )
+    )
+    client.sync("-j1")
+
+    for path in ("foo", "foo/bar", "foo-bar"):
+        assert (client.top / path / "f").read_text() == path
+    assert client.git("foo/bar", "status", "--porcelain") == ""
+
+    host.update_manifest(
+        manifest_xml(
+            '<project name="platform/foo" path="foo" />',
+            '<project name="platform/foo-bar" path="foo-bar" />',
+        )
+    )
+    client.sync()
+
+    assert set(client.list_projects()) == {"foo", "foo-bar"}
+    assert not (client.top / "foo/bar").exists()
+    assert (client.top / "foo/f").read_text() == "foo"
+
+
+def test_copyfile_linkfile(host: GitHost, client: RepoClient) -> None:
+    """copyfile and linkfile are created, updated and cleaned up.
+
+    linkfile symlinks are relative (0184dcc) so trees can be moved.
+    """
+    foo = host.create_repo(
+        "platform/foo", {"copy.txt": "v1", "dir/link.txt": "link"}
+    )
+    host.create_manifest(
+        manifest_xml(
+            '<project name="platform/foo" path="foo">'
+            '<copyfile src="copy.txt" dest="copied.txt" />'
+            '<linkfile src="dir/link.txt" dest="links/link.txt" />'
+            "</project>"
+        )
+    )
+    client.init(host.manifest_url)
+    client.sync()
+
+    link = client.top / "links/link.txt"
+    # Python <3.8 on Windows rejects Path objects here.
+    target = os.readlink(str(link))
+    assert target == os.path.join("..", "foo", "dir", "link.txt")
+    assert link.read_text() == "link"
+    assert (client.top / "copied.txt").read_text() == "v1"
+
+    foo.commit({"copy.txt": "v2"})
+    host.update_manifest(
+        manifest_xml(
+            '<project name="platform/foo" path="foo">'
+            '<copyfile src="copy.txt" dest="copied.txt" />'
+            "</project>"
+        )
+    )
+    client.sync()
+
+    assert (client.top / "copied.txt").read_text() == "v2"
+    assert not os.path.lexists(link)
+
+
+@pytest.mark.parametrize("sync_args", [[], ["--no-interleaved"]])
+def test_submodules(
+    host: GitHost, client: RepoClient, sync_args: List[str]
+) -> None:
+    """sync-s checks out & updates submodules, incl. for repeated projects.
+
+    Regression tests for 4623264 (b/444366154, `git submodule init` in
+    interleaved sync), 1b4e7a0 (the same repo checked out at multiple paths),
+    and 3a6e25a/3f087a8 (b/550074864, submodules follow their parent's new
+    revision in the same interleaved & phased sync).
+    """
+    sub = host.create_repo("platform/sub", {"s": "1"})
+    gitmodules = '[submodule "sub"]\n\tpath = sub\n\turl = ../sub\n'
+    foo = host.create_repo(
+        "platform/foo",
+        {".gitmodules": gitmodules, "sub": Gitlink(sub.rev_parse("main"))},
+    )
+    paths = ("a", "b")
+    # Track a branch, as gitlinks are only stale (b/550074864) when the
+    # parent's revision resolves before it's fetched (unlike new pinned SHAs).
+    # With sync-c, phased syncs skip fetching the stale (present) revision.
+    host.create_manifest(
+        manifest_xml(
+            *(
+                f'<project name="platform/foo" path="{p}" sync-s="true" '
+                'sync-c="true" />'
+                for p in paths
+            )
+        )
+    )
+
+    client.init(host.manifest_url)
+    client.sync(*sync_args)
+    for path in paths:
+        assert (client.top / path / "sub/s").read_text() == "1"
+        assert client.git(path, "config", "--get", "submodule.sub.url")
+
+    latest = foo.commit({"sub": Gitlink(sub.commit({"s": "2"}))})
+    client.sync(*sync_args)
+
+    for path in paths:
+        assert client.head(path) == latest
+        assert (client.top / path / "sub/s").read_text() == "2"
+
+
+# The default layout reads HEAD from the ref cache instead of GetHead().
+@pytest.mark.parametrize("init_args", [[], ["--worktree"]])
+def test_prune_detached_head(
+    host: GitHost, client: RepoClient, init_args: List[str]
+) -> None:
+    """`repo prune` handles projects with a detached HEAD.
+
+    Regression test for 7f7d70e (b/434077990).
+    """
+    host.create_repo("platform/foo", {"f": "foo"})
+    host.create_manifest(manifest_xml('<project name="platform/foo" />'))
+    client.init(host.manifest_url, *init_args)
+    client.sync()
+    path = "platform/foo"
+    client.run("start", "topic", "--all")
+    client.git(path, "checkout", "-q", "--detach")
+
+    client.run("prune")
+
+    assert not client.git(path, "branch", "--list", "topic")
+
+
+def test_submanifest_groups(host: GitHost, client: RepoClient) -> None:
+    """Submanifests apply their own default groups.
+
+    Regression test for cc88be3 (b/382086294).
+    """
+    for name in ("parent", "child", "child-extra"):
+        host.create_repo(f"platform/{name}", {"f": name})
+    host.create_repo(
+        "platform/child-manifest",
+        {
+            "default.xml": manifest_xml(
+                '<project name="platform/child" path="child" groups="g1" />',
+                '<project name="platform/child-extra" path="extra" />',
+            )
+        },
+    )
+    host.create_manifest(
+        manifest_xml(
+            '<project name="platform/parent" path="parent" />',
+            '<submanifest name="sub" project="platform/child-manifest" '
+            'revision="main" path="sub" default-groups="g1" />',
+        )
+    )
+
+    client.init(host.manifest_url)
+    client.sync()
+
+    assert client.list_projects() == {
+        "parent": "platform/parent",
+        "sub/child": "platform/child",
+    }
+    assert (client.top / "sub/child/f").read_text() == "child"
+    assert not (client.top / "sub/extra").exists()
diff --git a/tests/e2e/test_workflows.py b/tests/e2e/test_workflows.py
new file mode 100644
index 000000000..d91d5b310
--- /dev/null
+++ b/tests/e2e/test_workflows.py
@@ -0,0 +1,261 @@
+# 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.
+
+"""E2E tests for multi-step workflows, many from past point releases."""
+
+import os
+import re
+import time
+from typing import List
+
+from harness import GIT_DEFAULTS_PARAMS
+from harness import GitHost
+from harness import manifest_xml
+from harness import RepoClient
+from harness import run_git
+from harness import ServerRepo
+import pytest
+
+
+@pytest.mark.parametrize("git_defaults", GIT_DEFAULTS_PARAMS)
+@pytest.mark.parametrize(
+    "project_attrs",
+    ["", 'clone-depth="1"', 'sync-strategy="stateless"'],
+)
+def test_two_phase_sync(
+    host: GitHost, client: RepoClient, project_attrs: str
+) -> None:
+    """`repo sync -n` then `repo sync -l` before worktrees exist.
+
+    Regression tests for b/565047698 (v2.68.1, incl. e1e215a for stateless
+    syncs).
+    """
+    foo = host.create_repo("platform/foo", {"f": "1"})
+    host.create_manifest(
+        manifest_xml(
+            f'<project name="platform/foo" path="foo" {project_attrs} />'
+        )
+    )
+    client.init(host.manifest_url)
+
+    # The b/565047698 regression only logs a warning & still exits 0, so also
+    # require a clean stderr.
+    assert client.sync("-n").stderr == ""
+    assert not (client.top / "foo").exists()
+    # A second network-only sync (after upstream moved) with no worktree yet.
+    latest = foo.commit({"f": "2"})
+    assert client.sync("-n").stderr == ""
+    assert not (client.top / "foo").exists()
+
+    client.sync("-l")
+    assert client.head("foo") == latest
+    assert (client.top / "foo/f").read_text() == "2"
+
+    # And the checkout keeps working with regular syncs afterwards.
+    latest = foo.commit({"f": "3"})
+    client.sync()
+    assert client.head("foo") == latest
+
+
+@pytest.mark.parametrize(
+    "extra_init_args", [[], ["--manifest-upstream-branch", "main"]]
+)
+def test_init_manifest_commit(
+    host: GitHost, client: RepoClient, extra_init_args: List[str]
+) -> None:
+    """`repo init -b <sha>` pins the manifest to a raw commit.
+
+    Regression test for b/544041102 (v2.66.1).
+    """
+    host.create_repo("platform/foo", {"f": "foo"})
+    host.create_repo("platform/bar", {"f": "bar"})
+    manifest = host.create_manifest(
+        manifest_xml('<project name="platform/foo" />')
+    )
+    pinned = manifest.rev_parse("main")
+    host.update_manifest(
+        manifest_xml(
+            '<project name="platform/foo" />',
+            '<project name="platform/bar" />',
+        )
+    )
+
+    client.init(host.manifest_url, "-b", pinned, *extra_init_args)
+    client.sync()
+
+    assert client.list_projects() == {"platform/foo": "platform/foo"}
+    assert client.git(".repo/manifests", "rev-parse", "HEAD") == pinned
+
+
+@pytest.mark.parametrize("git_defaults", GIT_DEFAULTS_PARAMS)
+def test_mirror(host: GitHost, client: RepoClient) -> None:
+    """`repo init --mirror && repo sync` creates bare mirrors (v2.57.1)."""
+    foo = host.create_repo("platform/foo", {"f": "1"})
+    foo.commit({"f": "other"}, branch="other")
+    host.create_manifest(manifest_xml('<project name="platform/foo" />'))
+
+    client.init(host.manifest_url, "--mirror")
+    client.sync()
+
+    mirror = client.top / "platform/foo.git"
+
+    def mirror_rev(ref: str) -> str:
+        return run_git(f"--git-dir={mirror}", "rev-parse", ref, env=client.env)
+
+    assert not (client.top / "platform/foo").exists()
+    assert mirror_rev("refs/heads/main") == foo.rev_parse("main")
+    assert mirror_rev("refs/heads/other") == foo.rev_parse("other")
+
+    latest = foo.commit({"f": "2"})
+    client.sync()
+    assert mirror_rev("refs/heads/main") == latest
+
+
+def test_incremental_sync(host: GitHost, client: RepoClient) -> None:
+    """Syncs pick up new commits, new projects & removed projects."""
+    foo = host.create_repo("platform/foo", {"f": "1"})
+    host.create_repo("platform/bar", {"f": "bar"})
+    host.create_repo("platform/baz", {"f": "baz"})
+    host.create_manifest(
+        manifest_xml(
+            '<project name="platform/foo" path="foo" />',
+            '<project name="platform/bar" path="bar" />',
+        )
+    )
+    client.init(host.manifest_url)
+    client.sync()
+
+    latest = foo.commit({"f": "2", "new": "new"})
+    host.update_manifest(
+        manifest_xml(
+            '<project name="platform/foo" path="foo" />',
+            '<project name="platform/baz" path="baz" />',
+        )
+    )
+    client.sync()
+
+    assert client.head("foo") == latest
+    assert (client.top / "foo/new").read_text() == "new"
+    assert (client.top / "baz/f").read_text() == "baz"
+    assert not (client.top / "bar").exists()
+    assert client.list_projects() == {
+        "baz": "platform/baz",
+        "foo": "platform/foo",
+    }
+
+
+def test_rebase_local_work(host: GitHost, client: RepoClient) -> None:
+    """Local commits on a `repo start` branch are rebased by sync."""
+    foo = host.create_repo("platform/foo", {"f": "1"})
+    host.create_manifest(manifest_xml('<project name="platform/foo" />'))
+    client.init(host.manifest_url)
+    client.sync()
+
+    path = "platform/foo"
+    client.run("start", "topic", "--all")
+    (client.top / path / "local").write_text("local")
+    client.git(path, "add", "local")
+    client.git(path, "commit", "-q", "-m", "local change")
+    latest = foo.commit({"f": "2"})
+
+    client.sync()
+
+    assert client.git(path, "symbolic-ref", "--short", "HEAD") == "topic"
+    assert client.git(path, "rev-parse", "HEAD~1") == latest
+    assert (client.top / path / "local").read_text() == "local"
+
+
+def test_switch_manifest_branch(host: GitHost, client: RepoClient) -> None:
+    """Re-running `repo init -b` on an existing checkout switches branches."""
+    foo = host.create_repo("platform/foo", {"f": "main"})
+    release = foo.commit({"f": "release"}, branch="release")
+    host.create_manifest(
+        manifest_xml('<project name="platform/foo" path="foo" />')
+    )
+    host.update_manifest(
+        manifest_xml(
+            '<project name="platform/foo" path="foo" />',
+            default='remote="origin" revision="release"',
+        ),
+        branch="release",
+    )
+    client.init(host.manifest_url)
+    client.sync()
+    assert client.head("foo") == foo.rev_parse("main")
+
+    client.init(host.manifest_url, "-b", "release")
+    client.sync()
+
+    assert client.head("foo") == release
+
+
+@pytest.mark.parametrize(
+    "command",
+    [
+        ["selfupdate", "--no-repo-verify"],
+        ["sync", "--no-repo-verify"],
+    ],
+)
+def test_selfupdate(
+    host: GitHost,
+    client: RepoClient,
+    repo_source: ServerRepo,
+    command: List[str],
+) -> None:
+    """repo upgrades itself when its source moves forward."""
+    source = host.fork(repo_source, "git-repo")
+    client.repo_url = source.url
+    host.create_repo("platform/foo", {"f": "foo"})
+    host.create_manifest(manifest_xml('<project name="platform/foo" />'))
+    # Start from an existing synced checkout before publishing the repo update.
+    client.init(host.manifest_url)
+    client.sync()
+
+    latest = source.commit({"E2E_SELFUPDATE_MARKER": "new"})
+    # sync only checks for updates once a day.
+    fetch_head = client.repodir / "repo/.git/FETCH_HEAD"
+    old = time.time() - 2 * 24 * 60 * 60
+    os.utime(fetch_head, (old, old))
+
+    result = client.run(*command)
+
+    assert "A new version of repo is available" in result.stderr
+    assert client.git(".repo/repo", "rev-parse", "HEAD") == latest
+    assert (client.repodir / "repo/E2E_SELFUPDATE_MARKER").exists()
+    # The restarted (upgraded) repo keeps working.
+    assert "v99.0-e2e-1-g" in client.run("version").stdout
+
+
+def test_commands_after_sync(host: GitHost, client: RepoClient) -> None:
+    """Common read-only commands work on a freshly synced checkout."""
+    host.create_repo("platform/foo", {"f": "foo"})
+    host.create_manifest(manifest_xml('<project name="platform/foo" />'))
+    client.init(host.manifest_url)
+    client.sync()
+
+    for command, expected in (
+        (["status"], r"nothing to commit"),
+        (["info"], r"Manifest branch: main"),
+        (["branches"], r"\(no branches\)"),
+        # No local changes, so no output.
+        (["diff"], r"\A\Z"),
+        (["forall", "-c", "git", "log", "-1"], r"platform/foo: initial"),
+        # Projects are pinned to commit ids.
+        (["manifest", "-r"], r'revision="[0-9a-f]{40}"'),
+    ):
+        output = client.run(*command).output
+        assert re.search(expected, output), (
+            f"`repo {' '.join(command)}` output {output!r} "
+            f"did not match {expected!r}"
+        )