cpython/Misc/NEWS.d/next/C API/2024-06-11-21-38-32.gh-issue-70278.WDE4zM.rst

:c:func:`PyUnicode_FromFormat` no longer produces the ending ``\ufffd``
character for truncated C string when use precision with ``%s`` and ``%V``.
It now truncates the string before the start of truncated multibyte
sequences.