Issue #17278: Fix a crash in heapq.heappush() and heapq.heappop() when the list is being resized concurrently.
diff --git a/Lib/test/test_heapq.py b/Lib/test/test_heapq.py
index 5932a40..73b88f0 100644
--- a/Lib/test/test_heapq.py
+++ b/Lib/test/test_heapq.py
@@ -315,6 +315,16 @@
'Test multiple tiers of iterators'
return chain(imap(lambda x:x, R(Ig(G(seqn)))))
+class SideEffectLT:
+ def __init__(self, value, heap):
+ self.value = value
+ self.heap = heap
+
+ def __lt__(self, other):
+ self.heap[:] = []
+ return self.value < other.value
+
+
class TestErrorHandling(TestCase):
module = None
@@ -361,6 +371,22 @@
self.assertRaises(TypeError, f, 2, N(s))
self.assertRaises(ZeroDivisionError, f, 2, E(s))
+ # Issue #17278: the heap may change size while it's being walked.
+
+ def test_heappush_mutating_heap(self):
+ heap = []
+ heap.extend(SideEffectLT(i, heap) for i in range(200))
+ # Python version raises IndexError, C version RuntimeError
+ with self.assertRaises((IndexError, RuntimeError)):
+ self.module.heappush(heap, SideEffectLT(5, heap))
+
+ def test_heappop_mutating_heap(self):
+ heap = []
+ heap.extend(SideEffectLT(i, heap) for i in range(200))
+ # Python version raises IndexError, C version RuntimeError
+ with self.assertRaises((IndexError, RuntimeError)):
+ self.module.heappop(heap)
+
class TestErrorHandlingPython(TestErrorHandling):
module = py_heapq