bpo-39421: Fix posible crash in heapq with custom comparison operators (GH-18118)
* bpo-39421: Fix posible crash in heapq with custom comparison operators
* fixup! bpo-39421: Fix posible crash in heapq with custom comparison operators
* fixup! fixup! bpo-39421: Fix posible crash in heapq with custom comparison operators
diff --git a/Lib/test/test_heapq.py b/Lib/test/test_heapq.py
index 861ba75..6902573 100644
--- a/Lib/test/test_heapq.py
+++ b/Lib/test/test_heapq.py
@@ -432,6 +432,37 @@
with self.assertRaises((IndexError, RuntimeError)):
self.module.heappop(heap)
+ def test_comparison_operator_modifiying_heap(self):
+ # See bpo-39421: Strong references need to be taken
+ # when comparing objects as they can alter the heap
+ class EvilClass(int):
+ def __lt__(self, o):
+ heap.clear()
+ return NotImplemented
+
+ heap = []
+ self.module.heappush(heap, EvilClass(0))
+ self.assertRaises(IndexError, self.module.heappushpop, heap, 1)
+
+ def test_comparison_operator_modifiying_heap_two_heaps(self):
+
+ class h(int):
+ def __lt__(self, o):
+ list2.clear()
+ return NotImplemented
+
+ class g(int):
+ def __lt__(self, o):
+ list1.clear()
+ return NotImplemented
+
+ list1, list2 = [], []
+
+ self.module.heappush(list1, h(0))
+ self.module.heappush(list2, g(0))
+
+ self.assertRaises((IndexError, RuntimeError), self.module.heappush, list1, g(1))
+ self.assertRaises((IndexError, RuntimeError), self.module.heappush, list2, h(1))
class TestErrorHandlingPython(TestErrorHandling, TestCase):
module = py_heapq