[issue29838] Check that sq_length and mq_length return non-negative result

[Terry J. Reedy]

Terry J. Reedy added the comment:

The changes appear consistent within themselves (ie, no apparent typos), and the one for builtin len appears to fix a bug that would allow negative length.  Can tests be written in Python that fail without the patch?   Or would mis-behaving classes have to be written in C?

----------
nosy: +terry.reedy

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue29838>
_______________________________________