Use git ancestry to find proper parent release

release-controller/BUILD.bazel

@@ -1,5 +1,5 @@
 load("@python_deps//:requirements.bzl", "requirement")
-load("@rules_python//python:defs.bzl", "py_binary")
+load("@rules_python//python:defs.bzl", "py_binary", "py_library")
 load("@//tools/python:py_oci_image.bzl", "py_oci_image")
 
 deps = [

release-controller/git_repo.py

@@ -159,6 +159,20 @@ def fetch(self):
             cwd=self.dir,
         )
 
+    def is_ancestor(self, maybe_ancestor_commit: str, descendant_commit: str) -> bool:
+        return 0 == subprocess.check_call(
+            [
+                "git",
+                "merge-base",
+                "--is-ancestor",
+                maybe_ancestor_commit,
+                descendant_commit,
+            ],
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+            cwd=self.dir,
+        )
+
 
 # TODO: test
 def push_release_tags(repo: GitRepo, release: Release):

release-controller/reconciler.py

@@ -8,6 +8,8 @@
 import time
 import traceback
 
+
+sys.path.append(os.path.join(os.path.dirname(__file__)))
 import __fix_import_paths  # isort:skip  # noqa: F401 # pylint: disable=W0611
 import release_index
 import requests
@@ -89,6 +91,22 @@ def versions_to_unelect(
     return [v for v in elected_versions if v not in active_releases_versions and v not in active_versions]
 
 
+def find_parent_release_commit(ic_repo: GitRepo, config: release_index.Model, commit: str) -> str:
+    rc, rc_idx = next(
+        (rc, i) for i, rc in enumerate(config.root.releases) if any(v.version == commit for v in rc.versions)
+    )
+    v_idx = next(i for i, v in enumerate(config.root.releases[rc_idx].versions) if v.version == commit)
+    return (
+        config.root.releases[rc_idx + 1].versions[0].version  # take first version from the previous rc
+        if v_idx == 0
+        else next(
+            v.version
+            for i, v in reversed(list(enumerate(rc.versions[: v_idx - 1])))
+            if i == 0 or ic_repo.is_ancestor(v.version, commit)
+        )
+    )
+
+
 # https://stackoverflow.com/a/44873382
 def sha256sum(filename):
     h = hashlib.sha256()
@@ -173,11 +191,7 @@ def reconcile(self):
                 push_release_tags(self.ic_repo, rc)
                 self.notes_client.ensure(
                     version_name=version_name(rc_name=rc.rc_name, name=v.name),
-                    since_commit=(
-                        config.root.releases[rc_idx + 1].versions[0].version  # take first version from the previous rc
-                        if v_idx == 0
-                        else rc.versions[v_idx - 1].version  # take previous version from the same rc
-                    ),
+                    since_commit=find_parent_release_commit(self.ic_repo, config, v.version),
                     git_revision=v.version,
                     tag_teams_on_create=v_idx == 0,
                 )

release-controller/test_reconciler.py

@@ -13,7 +13,7 @@
 from mock_google_docs import ReleaseNotesClientMock
 from publish_notes import PublishNotesClient
 from pydantic_yaml import parse_yaml_raw_as
-from reconciler import oldest_active_release
+from reconciler import find_parent_release_commit, oldest_active_release
 from reconciler import Reconciler
 from reconciler import ReconcilerState
 from reconciler import version_package_checksum
@@ -297,3 +297,56 @@ def mock_download_files(url: str, timeout: int = 10):  # pylint: disable=unused-
         assert requests.get.call_count == 3  # pylint: disable=no-member
 
     assert repr(e.value) == repr(RuntimeError("checksums do not match"))
+
+
+def test_find_parent_release_commit():
+    ic_repo = git_repo.GitRepo(f"https://github.com/dfinity/ic.git", main_branch="master")
+    test_cases = [
+        SimpleNamespace(
+            name="parent is not the directly preceding release version",
+            input="48c500d1501e4165fc183e508872a2ef13fd0bef",
+            want="246d0ce0784d9990c06904809722ce5c2c816269",
+            index=parse_yaml_raw_as(
+                release_index.Model,
+                """
+releases:
+  - rc_name: rc--2024-06-12_23-01
+    versions:
+      - name: base
+        version: 246d0ce0784d9990c06904809722ce5c2c816269
+      - name: storage-layer-disabled
+        version: 2dfe3a1864d1b9a6df462e9503adf351036e7965
+      - name: cycle-hotfix
+        version: 48c500d1501e4165fc183e508872a2ef13fd0bef
+""",
+            ),
+        ),
+        SimpleNamespace(
+            name="parent is not the directly preceding release version",
+            input="246d0ce0784d9990c06904809722ce5c2c816269",
+            want="d19fa446ab35780b2c6d8b82ea32d808cca558d5",
+            index=parse_yaml_raw_as(
+                release_index.Model,
+                """
+releases:
+  - rc_name: rc--2024-06-12_23-01
+    versions:
+      - name: base
+        version: 246d0ce0784d9990c06904809722ce5c2c816269
+      - name: storage-layer-disabled
+        version: 2dfe3a1864d1b9a6df462e9503adf351036e7965
+      - name: cycle-hotfix
+        version: 48c500d1501e4165fc183e508872a2ef13fd0bef
+  - rc_name: rc--2024-06-05_23-01
+    versions:
+      - name: base
+        version: d19fa446ab35780b2c6d8b82ea32d808cca558d5
+      - name: storage-layer-disabled
+        version: 08f32722df2f56f1e5c1e603fee0c87c40b77cba
+""",
+            ),
+        ),
+    ]
+
+    for tc in test_cases:
+        assert find_parent_release_commit(ic_repo, tc.index, tc.input) == tc.want