Armin Rigo added the comment: Ah, sorry. Ok. Now a different issue: the user-defined function can return an interned string. If it has a refcount of 1, _PyString_FormatLong() will mutate it. Then when we DECREF it, string_dealloc() will not find it any more in the interned dict and crash with a fatal error.
Note that I'm mostly having fun finding holes in delicate logic, like mutating strings in-place. It would be much more simple to either (1) stop calling the user-defined functions and behave similarly to most other built-in types; or (2) stop trying to mutate that poor string in-place and always just create a new one. :-) ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue11145> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
