Message 122465 - Python tracker

AFAICT, all ctype methods (isalpha, isdigit, etc.) have the same problem.  I posted a patch at issue10542 that introduces a Py_UNICODE_NEXT() macro that can help fixing all these methods.  I am adding #10542 as a dependency and if there are no objections, I will change the title to extend the scope of this issue to cover all ctype methods.