(RHEL-18768) time-util: fix buffer-over-run

[brozs]

Fixes #23928.

(cherry picked from commit 9102c625a673a3246d7e73d8737f3494446bad4e)

Note there is an existing backport commit (a521f94) in the rhel-8.8.0 branch but that has placed the following section in test_format_timespan() in src/test/test-time-util.c, thus calling the test asserts on each test_format_timespan() call, while I believe it is more appropriate in the main():

        /* See issue #23928. */
        _cleanup_free_ char *buf;
        assert_se(buf = new(char, 5));
        assert_se(buf == format_timespan(buf, 5, 100005, 1000));

Please advise.

Resolves: RHEL-18768

[github-actions]

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Tracker - RHEL-18768

The following commits meet all requirements

commit	upstream
b2c54cc - time-util: fix buffer-over-run	systemd/systemd@9102c62

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🟢 Tracker RHEL-18768 has set desired product: rhel-8.6.0.z
🟢 Tracker RHEL-18768 has set desired component: systemd
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[dtardon]

Note there is an existing backport commit (a521f94) in the rhel-8.8.0 branch but that has placed the following section in test_format_timespan() in src/test/test-time-util.c, thus calling the test asserts on each test_format_timespan() call, while I believe it is more appropriate in the main():

I don't think it matters. Who cares if that particular check is done multiple times? If it took 5 minutes to finish, then it might have been a concern. But it doesn't...

[dtardon]

LGTM