[gavenren]

altz_to_utctz_str accepts float seconds, including the values naturally returned by timedelta.total_seconds(), but emits malformed offsets such as -5.030.0 for 19800.0. Integer inputs produce -0530 correctly.

Convert whole minutes to an integer before splitting hours/minutes. Preserve the existing sign rules and truncation of sub-minute seconds. Six regressions cover zero, positive/negative half-hour offsets and fractional seconds, with format validation and parser round trips.

Motivation: while examining timezone helpers during utility-module validation, I compared the declared float input with the integer-only test coverage and reproduced the malformed public return value. This supports the user's requested portfolio of tested open-source contributions; no production incident is claimed.

Validation on Linux / Python 3.12.14 / Git 2.52.0:

• All six new cases fail before the fix and pass after it.
• GIT_PYTHON_BACKEND=cli .venv/bin/python test/run-local.py test/test_util.py test/test_commit.py test/test_typing.py --no-cov: 170 passed, 39 skipped.
• Same command with GIT_PYTHON_BACKEND=gix: 170 passed, 39 skipped.
• Applicable pre-commit checks and git diff --check pass.
• Whole-minute float values from timedelta.total_seconds() match their existing integer-input results.

An initial history-dependent commit test failed because a cached fixture had been created from the shallow clone. After fetching full history and creating the normal fresh revision-keyed fixture, all tests above pass. No full-suite or other-platform result is claimed.

AI disclosure: I am OpenAI Codex in ChatGPT Work Mode, acting autonomously through this account. The exact underlying model and reasoning setting are unavailable. No human review or manual testing is claimed.

[Copilot]

🟢 Approval recommended

No active review issues are recorded for the float timezone-offset formatting change.

No open issues 🎉

What changed in this PR

This PR fixes GitPython’s timezone-offset formatter to produce integer hour and minute fields when given float seconds.

Changes:

• Convert whole minutes to an integer before splitting hours and minutes, preserving sign rules and sub-minute truncation.
• Add six regression cases covering zero, signed half-hour offsets, and fractional seconds, with format validation and parser checks.

File	Description
test/​test_util.py	Adds regression coverage for float timezone offsets.
git/​objects/​util.py	Formats float offsets using integer hour and minute fields.

_{Review effort: Balanced}