From e59c9cde99172ba5f45964c18540476fd9f43f27 Mon Sep 17 00:00:00 2001 From: Gavin Mak Date: Tue, 25 Aug 2026 08:59:37 -0700 Subject: [PATCH] cherry_pick: resolve and read commits in one process Send a typed revision expression to cat-file --batch over stdin and parse its object header and exact byte length. This safely resolves the commit OID and retrieves its raw message in one Git process instead of separate rev-parse and cat-file calls. Bug: 553599402 Change-Id: I764894323ec28e134f2523bd1d5694738b6b52d0 Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/623903 Reviewed-by: Brian Gan Tested-by: Gavin Mak Commit-Queue: Gavin Mak --- subcmds/cherry_pick.py | 75 ++++++++++++++++----------- tests/test_subcmds_cherry_pick.py | 85 +++++++++++++++++++++++++++++++ 2 files changed, 130 insertions(+), 30 deletions(-) create mode 100644 tests/test_subcmds_cherry_pick.py diff --git a/subcmds/cherry_pick.py b/subcmds/cherry_pick.py index 3d2193339..4e7b978c8 100644 --- a/subcmds/cherry_pick.py +++ b/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] - - p = GitCommand( - 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) + sha1, commit = self._ResolveReference(reference) + old_msg = self._StripHeader(commit) 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) diff --git a/tests/test_subcmds_cherry_pick.py b/tests/test_subcmds_cherry_pick.py new file mode 100644 index 000000000..b52efc86b --- /dev/null +++ b/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")