From 93677f075df9a23c036f4baeb2b9f67c784eadbc Mon Sep 17 00:00:00 2001 From: Armin Rigo Date: Thu, 29 Jul 2004 12:40:23 +0000 Subject: * 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. --- Include/listobject.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'Include') diff --git a/Include/listobject.h b/Include/listobject.h index ffce029fac..43048d33db 100644 --- a/Include/listobject.h +++ b/Include/listobject.h @@ -30,9 +30,7 @@ typedef struct { * 0 <= ob_size <= allocated * len(list) == ob_size * ob_item == NULL implies ob_size == allocated == 0 - * If ob_item ever becomes non-NULL, it remains non-NULL for the - * life of the list object. The check for mutation in list.sort() - * relies on this odd detail. + * list.sort() temporarily sets allocated to -1 to detect mutations. */ int allocated; } PyListObject; -- cgit v1.2.1