[Python-Dev] various unix platform build/test issues

[Tim Peters]

[Neal Norwitz]
>   * AIX sorts numbers and strings in a different order than Linux:
>
>         >>> 'ick' >= 0  # Linux
>         True
>
>         >>> 'ick' >= 0  # AIX
>         False
>
>      This causes failures for test_descrtut and test_random.

It shouldn't.  Regardless of platform, this should end up at the tail end of
default_3way_compare(), resolved by the

	c = strcmp(vname, wname);

line with vname "str" and wname "" (an empty string).

But-- ick! --it doesn't, and not on any platform anymore.  vname and wname
are both empty strings now, so it goes on to compare the objects by memory
address and the outcome is pure accident ... this is because rev 2.197 of
stringobject.c gave string objects a non-NULL tp_as_number slot for the
first time.  The intent of the emtpy-string gimmick was to make all numeric
objects "less than" all non-numeric objects (excepting None, which is less
than every non-None value), in particular so that sorting a list would bring
all the number-like thingies next to each other.  Strings weren't intended
to take part in this number gimmick too.  Then again, comparison is so snaky
it's hard to predict what it will do.  In any case, this is incompatible
with previous Python releases.  Neil(S), was giving strings a tp_as_number
slot necessary?  Or just the least painful way to fix whatever bug it was
fixing?  I suppose the tail end of default_3way_compare could grow more
special cases to exempt strings from being treated like numbers for the
purpose of comparison.