[ python-Bugs-1022813 ] test_xrange fails on osf1 v5.1b

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Bugs item #1022813, was opened at 2004-09-05 20:10
Message generated for change (Comment added) made by nnorwitz
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1022813&group_id=5470

Category: Python Interpreter Core
Group: Python 2.4
Status: Open
Resolution: None
Priority: 6
Submitted By: roadkill (dharma_roadkill)
Assigned to: Nobody/Anonymous (nobody)
Summary: test_xrange fails on osf1 v5.1b

Initial Comment:
On a build of Python 2.4a3:
uname -a: OSF1 xxx.tnzi.com V5.1 2650 alpha alpha


> ./python ./Lib/test/test_xrange.py
test_xrange (__main__.XrangeTest) ... ERROR

==========================================
============================
ERROR: test_xrange (__main__.XrangeTest)
------------------------------------------------------
----------------
Traceback (most recent call last):
  File "./Lib/test/test_xrange.py", line 56, in test_xrange
    self.assertEqual(len(xrange(-sys.maxint, sys.maxint, 
2)),
ValueError: xrange object size cannot be reported

------------------------------------------------------
----------------
Ran 1 test in 0.001s

FAILED (errors=1)
Traceback (most recent call last):
  File "./Lib/test/test_xrange.py", line 64, in ?
    test_main()
  File "./Lib/test/test_xrange.py", line 61, in test_main
    test.test_support.run_unittest(XrangeTest)
  File "/u03/home/doug/python/Python-
2.4a3/Lib/test/test_support.py", line 290,
in run_unittest
    run_suite(suite, testclass)
  File "/u03/home/doug/python/Python-
2.4a3/Lib/test/test_support.py", line 275,
in run_suite
    raise TestFailed(err)
test.test_support.TestFailed: Traceback (most recent 
call last):
  File "./Lib/test/test_xrange.py", line 56, in test_xrange
    self.assertEqual(len(xrange(-sys.maxint, sys.maxint, 
2)),
ValueError: xrange object size cannot be reported

Everything else seems to work.



----------------------------------------------------------------------

>Comment By: Neal Norwitz (nnorwitz)
Date: 2004-09-06 22:52

Message:
Logged In: YES 
user_id=33168

I haven't thought too much about this, but ISTM that the
code is correct and the test needs to be updated. 
Unfortunately, I don't think there's anyway to test for
LONG_MAX != INT_MAX.  I think the best we could do is
disable this test if sys.maxint > 0x7fffffff. Hmmm, you
could probably use the struct module and find out the size
of ints and longs.  (struct.calcsize('i') and
struct.calcsize('l')).

But I'm tired, so all this could be non-sense.

----------------------------------------------------------------------

Comment By: Raymond Hettinger (rhettinger)
Date: 2004-09-05 20:36

Message:
Logged In: YES 
user_id=80475

I haven't looked into a solution yet but want to record what
I've found so far.  In checkin 2.44 on 9/11/2002, guido noted,

""" Untested code for 64-bit platforms.  range_length() is
declared as int but returns r->len which is a long.  This
doesn't even cause a warning on 32-bit platforms, but can
return bogus values on 64-bit platforms (and should cause a
compiler warning).  Fix this by inserting a range check when
LONG_MAX != INT_MAX, and adding an explicit cast to (int)
when the test passes.  When r->len is out of range,
PySequence_Size()
and hence len() will report an error (but an iterator will still
work).
"""

The code for the check is:

static int
range_length(rangeobject *r)
{
#if LONG_MAX != INT_MAX
	if (r->len > INT_MAX) {
		PyErr_SetString(PyExc_ValueError,
				"xrange object size cannot be reported");
		return -1;
	}
#endif
	return (int)(r->len);
}

----------------------------------------------------------------------

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