> New changeset 7132bca093ad by Victor Stinner in branch 'default':
> Close #16757: Avoid calling the expensive _PyUnicode_FindMaxChar() function

This changeset is almost the same than unicode_findmaxchar_2.patch. I prefered to keep the API unchanged and not call _PyUnicode_FindMaxChar() instead of adding a test in the function to exit it.

There is just a minor difference in Python/formatter_unicode.c: the test for _PyUnicode_FindMaxChar() is done after the test on format->fill_char (which should avoid a call to for _PyUnicode_FindMaxChar() if fill_char is wider than the actual buffer).

Thanks Serhiy for your great idea!