branch_worker: Fix _series_already_applied() helper

After a partial `git am` failure (some patches in a series apply
successfully before one hits a merge conflict), _series_already_applied()
walks commit history starting from the current HEAD. This HEAD includes
commits that were just created by the partially-successful `git am`,
so the function matches the series' own patch subjects against its own
just-applied commits and incorrectly concludes the series was "already
merged" into upstream.

The consequence is that a NewPRWithNoChangeException is raised instead of
creating a merge-conflict PR. The series remains in-queue on Patchwork
with no corresponding GitHub PR, producing a persistent KPD/Patchwork
discrepancy.

Fix this by adding an explicit `rev` parameter to
_series_already_applied() and passing it through to repo.iter_commits().
The caller now supplies the upstream remote-tracking ref
(e.g. "upstream/bpf-next"), so the history walk is anchored to the
genuine upstream branch tip rather than the working HEAD that may contain
partially-applied series commits.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Ihor Solodrai <isolodrai@meta.com>

Author: theihor

kernel_patches_daemon/branch_worker.py

@@ -580,10 +580,10 @@ def _reset_repo(repo, branch: str) -> None:
     repo.git.checkout(branch)
 
 
-async def _series_already_applied(repo: git.Repo, series: Series) -> bool:
+async def _series_already_applied(repo: git.Repo, series: Series, rev: str) -> bool:
     """
     Returns whether or not the given series has already been applied
-    to the active branch on `repo`.
+    to the given revision in `repo`.
 
     We consider even a single applied patch in a series as the series being
     applied. This is b/c the applied patch is marked as "accepted" and thus the
@@ -597,7 +597,7 @@ async def _series_already_applied(repo: git.Repo, series: Series) -> bool:
     try:
         summaries = {
             commit.summary.lower()
-            for commit in repo.iter_commits(max_count=ALREADY_MERGED_LOOKBACK)
+            for commit in repo.iter_commits(rev, max_count=ALREADY_MERGED_LOOKBACK)
         }
     except git.exc.GitCommandError:
         logger.exception("Failed to check series application status")
@@ -687,7 +687,7 @@ def __init__(
         self.repo_dir = _uniq_tmp_folder(repo_url, repo_branch, base_directory)
         self.repo_branch = repo_branch
         self.repo_pr_base_branch = repo_branch + "_base"
-        self.repo_local = None
+        self.repo_local: Optional[git.Repo] = None
 
         self.upstream_url = upstream_url
         self.upstream_branch = upstream_branch
@@ -844,7 +844,6 @@ def fetch_repo_branch(self) -> None:
         """
         Fetch the repository branch of interest only once
         """
-        # pyrefly: ignore  # bad-assignment
         self.repo_local = self.fetch_repo(
             self.repo_dir, self.repo_url, self.repo_branch
         )
@@ -1109,8 +1108,12 @@ async def apply_push_comment(
             # In other words, patchwork could be reporting a relevant
             # status (ie. !accepted) while the series has already been
             # merged and pushed.
-            # pyrefly: ignore  # bad-argument-type
-            if await _series_already_applied(self.repo_local, series):
+            assert self.repo_local is not None
+            if await _series_already_applied(
+                self.repo_local,
+                series,
+                f"{UPSTREAM_REMOTE_NAME}/{self.upstream_branch}",
+            ):
                 logger.info(f"Series {series.url} already applied to tree")
                 raise NewPRWithNoChangeException(self.repo_pr_base_branch, branch_name)
 

tests/test_branch_worker.py

@@ -1015,7 +1015,7 @@ async def test_applied_all(self, m: aioresponses):
         in_1 = ALREADY_MERGED_LOOKBACK + 33
         in_2 = ALREADY_MERGED_LOOKBACK + 34
         series = await self._get_series(m, [f"Commit {in_1}", f"[tag] Commit {in_2}"])
-        self.assertTrue(await _series_already_applied(self.repo, series))
+        self.assertTrue(await _series_already_applied(self.repo, series, "HEAD"))
 
     @aioresponses()
     async def test_applied_none_newer(self, m: aioresponses):
@@ -1024,26 +1024,26 @@ async def test_applied_none_newer(self, m: aioresponses):
         series = await self._get_series(
             m, [f"[some tags]Commit {out_1}", f"[tag] Commit {out_2}"]
         )
-        self.assertFalse(await _series_already_applied(self.repo, series))
+        self.assertFalse(await _series_already_applied(self.repo, series, "HEAD"))
 
     @aioresponses()
     async def test_applied_none_older(self, m: aioresponses):
         series = await self._get_series(m, ["[some tags]Commit 33", "[tag] Commit 34"])
-        self.assertFalse(await _series_already_applied(self.repo, series))
+        self.assertFalse(await _series_already_applied(self.repo, series, "HEAD"))
 
     @aioresponses()
     async def test_applied_some(self, m: aioresponses):
         inside = ALREADY_MERGED_LOOKBACK + 55
         out = ALREADY_MERGED_LOOKBACK * 3
         series = await self._get_series(m, [f"Commit {inside}", f"Commit {out}"])
-        self.assertTrue(await _series_already_applied(self.repo, series))
+        self.assertTrue(await _series_already_applied(self.repo, series, "HEAD"))
 
     @aioresponses()
     async def test_applied_all_case_insensitive(self, m: aioresponses):
         in_1 = ALREADY_MERGED_LOOKBACK + 33
         in_2 = ALREADY_MERGED_LOOKBACK + 34
         series = await self._get_series(m, [f"commit {in_1}", f"[tag] COMMIT {in_2}"])
-        self.assertTrue(await _series_already_applied(self.repo, series))
+        self.assertTrue(await _series_already_applied(self.repo, series, "HEAD"))
 
 
 class TestBranchChanged(unittest.TestCase):