[Python-checkins] python/dist/src/Lib/test test_sort.py,1.12,1.13

[arigo at users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Lib/test
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv28350/Lib/test

Modified Files:
	test_sort.py 
Log Message:
* drop the unreasonable list invariant that ob_item should never come back
  to NULL during the lifetime of the object.

* listobject.c nevertheless did not conform to the other invariants,
  either; fixed.

* listobject.c now uses list_clear() as the obvious internal way to clear
  a list, instead of abusing list_ass_slice() for that.  It makes it easier
  to enforce the invariant about ob_item == NULL.

* listsort() sets allocated to -1 during sort; any mutation will set it
  to a value >= 0, so it is a safe way to detect mutation.  A negative
  value for allocated does not cause a problem elsewhere currently.
  test_sort.py has a new test for this fix.

* listsort() leak: if items were added to the list during the sort, AND if
  these items had a __del__ that puts still more stuff into the list,
  then this more stuff (and the PyObject** array to hold them) were
  overridden at the end of listsort() and never released.


Index: test_sort.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_sort.py,v
retrieving revision 1.12
retrieving revision 1.13
diff -C2 -d -r1.12 -r1.13
*** test_sort.py	18 Jan 2004 20:29:55 -0000	1.12
--- test_sort.py	29 Jul 2004 12:40:22 -0000	1.13
***************
*** 151,154 ****
--- 151,171 ----
          self.assertEqual(L, range(50))
  
+     def test_undetected_mutation(self):
+         # Python 2.4a1 did not always detect mutation
+         memorywaster = []
+         for i in range(20):
+             def mutating_cmp(x, y):
+                 L.append(3)
+                 L.pop()
+                 return cmp(x, y)
+             L = [1,2]
+             self.assertRaises(ValueError, L.sort, mutating_cmp)
+             def mutating_cmp(x, y):
+                 L.append(3)
+                 del L[:]
+                 return cmp(x, y)
+             self.assertRaises(ValueError, L.sort, mutating_cmp)
+             memorywaster = [memorywaster]
+ 
  #==============================================================================