Issue #9669: Protect re against infinite loops on zero-width matching in
non-greedy repeat. Patch by Matthew Barnett.
diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py
index a9d6f2c..6ddddda 100644
--- a/Lib/test/test_re.py
+++ b/Lib/test/test_re.py
@@ -628,6 +628,15 @@
self.assertEqual(re.match('(x)*y', 50000*'x'+'y').group(1), 'x')
self.assertEqual(re.match('(x)*?y', 50000*'x'+'y').group(1), 'x')
+ def test_unlimited_zero_width_repeat(self):
+ # Issue #9669
+ self.assertIsNone(re.match(r'(?:a?)*y', 'z'))
+ self.assertIsNone(re.match(r'(?:a?)+y', 'z'))
+ self.assertIsNone(re.match(r'(?:a?){2,}y', 'z'))
+ self.assertIsNone(re.match(r'(?:a?)*?y', 'z'))
+ self.assertIsNone(re.match(r'(?:a?)+?y', 'z'))
+ self.assertIsNone(re.match(r'(?:a?){2,}?y', 'z'))
+
def test_scanner(self):
def s_ident(scanner, token): return token
def s_operator(scanner, token): return "op%s" % token