match Python 2.5 speed despite the __instancecheck__ / __subclasscheck__
mechanism. In the process, fix a bug where isinstance() and issubclass(),
when given a tuple of classes as second argument, were looking up
__instancecheck__ / __subclasscheck__ on the tuple rather than on each
type object.
Reviewed by Benjamin Peterson and Raymond Hettinger.
test.test_support.catch_warning is more full-featured and provides the same
functionality.
Since guard_warnings_filter was added in 2.6 there is no
backwards-compatibility issues.
The problem of checking too eagerly for recursive calls is the
following: if a RuntimeError is caused by recursion, and if code needs
to normalize it immediately (as in the 2nd test), then
PyErr_NormalizeException() needs a call to the RuntimeError class to
instantiate it, and this hits the recursion limit again... causing
PyErr_NormalizeException() to never finish.
Moved this particular recursion check to slot_tp_call(), which is not
involved in instantiating built-in exceptions.
Backport candidate.
from ?iga Seilnacht (sorry about the name, but Firefox
on my box can't display the first character of the name --
the SF "Unix name" is zseil).
This appears to cure the oddball intermittent leaks across
runs when running test_exceptions under -R. I'm not sure
why, but I'm too sleepy to care ;-)
The thrust of the SF patch was to remove randomness in the
pickle protocol used. I changed the patch to use
range(pickle.HIGHEST_PROTOCOL + 1), to try both pickle and
cPickle, and randomly mucked with other test lines to put
statements on their own lines.
Not a bugfix candidate (this is fiddling new-in-2.5 code).
