SF bug 555042: zip() may trigger MemoryError.
NOT a bugfix candidate: this is a fix to an optimization introduced
in 2.3.
diff --git a/Lib/test/test_b2.py b/Lib/test/test_b2.py
index 72810cb..459fd6b 100644
--- a/Lib/test/test_b2.py
+++ b/Lib/test/test_b2.py
@@ -344,7 +344,17 @@
if not exc:
raise TestFailed, 'zip(a, b) - missing expected TypeError'
+# Make sure zip doesn't try to allocate a billion elements for the
+# result list when one of its arguments doesn't say how long it is.
+# A MemoryError is the most likely failure mode.
+class SequenceWithoutALength:
+ def __getitem__(self, i):
+ if i == 5:
+ raise IndexError
+ else:
+ return i
+vereq(zip(SequenceWithoutALength(), xrange(2**30)),
+ list(enumerate(range(5))))
# Epilogue -- unlink the temp file
-
unlink(TESTFN)