SF patch #943898

Reads better when the iterable is a generator expression.

We need to write more; hopefully the barrier is a little lower now.

Make sure the start argument is not negative.

(Contributed by Andrew Gaul.)

a long time ago for VC6.

Beardsley.

If the seconds are different, we still need to calculate the differences
between milliseconds.

Also, on a Gentoo Linux (2.6.5) dual Athlon MP box with glibc 2.3,
time can go backwards.  This probably happens when the process switches
the CPU it's running on.  Time can also go backwards when running NTP.
If we detect a negative time delta (ie, time went backwards), return
a delta of 0.  This prevents an illegal array access elsewhere.
I think it's safest to *not* update prev_timeofday in this case, so we
return without updating.

Backport candidate.

Maxheap version of heapq.smallest() is forthcoming.

an alternate algorithm when the number of selected items is small
relative to the full iterable.

* Change a XDECREF to DECREF (adding an assertion just to be sure).

This is basically the support for package data from Phillip Eby's
setuptools package.  I've changed it only to fit it into the core
implementation rather than to live in subclasses, and added
documentation.

[ 971323 ] make test_signal less annoying
after some comments on IRC from a highly opinionated australian who
wishes to remain anonymous.

Ignore it, rather than breaking.

Will backport.

(and r1.1000 for Misc/NEWS!)

have a __module__. Test for this case.

Bugfix candidate, will backport.

tests which nicely highly highlight weaknesses).

* Initial value is now a large prime.
* Pre-multiply by the set length to add one more basis of differentiation.
* Work a bit harder inside the loop to scatter bits from sources that
  may have closely spaced hash values.

All of this is necessary to make up for keep the hash function commutative.
Fortunately, the hash value is cached so the call to frozenset_hash() will
only occur once per set.

* Non-zero initial value so that hash(frozenset()) != hash(0).
* Final permutation to differentiate nested sets.
* Add logic to make sure that -1 is not a possible hash value.

Prevents a collision pattern that occurs with nested tuples.
(Yitz Gale provided code that repeatably demonstrated the weakness.)