[pypy-commit] pypy list-strategies: stop must not be smaller than start in rpython

[l.diekmann]

Author: Lukas Diekmann <lukas.diekmann at uni-duesseldorf.de>
Branch: list-strategies
Changeset: r47514:527e4a735f22
Date: 2011-07-08 14:29 +0200
http://bitbucket.org/pypy/pypy/changeset/527e4a735f22/

Log:	stop must not be smaller than start in rpython

diff --git a/pypy/objspace/std/listobject.py b/pypy/objspace/std/listobject.py
--- a/pypy/objspace/std/listobject.py
+++ b/pypy/objspace/std/listobject.py
@@ -518,12 +518,13 @@
     getitems = getitems_copy
 
     def getslice(self, w_list, start, stop, step, length):
-        if step == 1:
+        if step == 1 and 0 <= start <= stop:
             l = self.cast_from_void_star(w_list.lstorage)
             assert start >= 0
             assert stop >= 0
             sublist = l[start:stop]
             storage = self.cast_to_void_star(sublist)
+            #XXX check of empty list?
             return W_ListObject.from_storage_and_strategy(self.space, storage, self)
         else:
             subitems_w = [None] * length
diff --git a/pypy/objspace/std/test/test_listobject.py b/pypy/objspace/std/test/test_listobject.py
--- a/pypy/objspace/std/test/test_listobject.py
+++ b/pypy/objspace/std/test/test_listobject.py
@@ -527,6 +527,7 @@
 
         l = [1,2,3,4,5]
         assert l[1:0:None] == []
+        assert l[1:0] == []
 
     def test_delall(self):
         l = l0 = [1,2,3]