1 files changed, 57 insertions, 0 deletions
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index a813616..09622dd 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -1156,6 +1156,63 @@ class MixinStrUnicodeUserStringTest:
         self.checkraises(ValueError, S, 'rpartition', '')
         self.checkraises(TypeError, S, 'rpartition', None)
 
+    def test_none_arguments(self):
+        # issue 11828
+        s = 'hello'
+        self.checkequal(2, s, 'find', 'l', None)
+        self.checkequal(3, s, 'find', 'l', -2, None)
+        self.checkequal(2, s, 'find', 'l', None, -2)
+        self.checkequal(0, s, 'find', 'h', None, None)
+
+        self.checkequal(3, s, 'rfind', 'l', None)
+        self.checkequal(3, s, 'rfind', 'l', -2, None)
+        self.checkequal(2, s, 'rfind', 'l', None, -2)
+        self.checkequal(0, s, 'rfind', 'h', None, None)
+
+        self.checkequal(2, s, 'index', 'l', None)
+        self.checkequal(3, s, 'index', 'l', -2, None)
+        self.checkequal(2, s, 'index', 'l', None, -2)
+        self.checkequal(0, s, 'index', 'h', None, None)
+
+        self.checkequal(3, s, 'rindex', 'l', None)
+        self.checkequal(3, s, 'rindex', 'l', -2, None)
+        self.checkequal(2, s, 'rindex', 'l', None, -2)
+        self.checkequal(0, s, 'rindex', 'h', None, None)
+
+        self.checkequal(2, s, 'count', 'l', None)
+        self.checkequal(1, s, 'count', 'l', -2, None)
+        self.checkequal(1, s, 'count', 'l', None, -2)
+        self.checkequal(0, s, 'count', 'x', None, None)
+
+        self.checkequal(True, s, 'endswith', 'o', None)
+        self.checkequal(True, s, 'endswith', 'lo', -2, None)
+        self.checkequal(True, s, 'endswith', 'l', None, -2)
+        self.checkequal(False, s, 'endswith', 'x', None, None)
+
+        self.checkequal(True, s, 'startswith', 'h', None)
+        self.checkequal(True, s, 'startswith', 'l', -2, None)
+        self.checkequal(True, s, 'startswith', 'h', None, -2)
+        self.checkequal(False, s, 'startswith', 'x', None, None)
+
+    def test_find_etc_raise_correct_error_messages(self):
+        # issue 11828
+        s = 'hello'
+        x = 'x'
+        self.assertRaisesRegexp(TypeError, r'^find\(', s.find,
+                                x, None, None, None)
+        self.assertRaisesRegexp(TypeError, r'^rfind\(', s.rfind,
+                                x, None, None, None)
+        self.assertRaisesRegexp(TypeError, r'^index\(', s.index,
+                                x, None, None, None)
+        self.assertRaisesRegexp(TypeError, r'^rindex\(', s.rindex,
+                                x, None, None, None)
+        self.assertRaisesRegexp(TypeError, r'^count\(', s.count,
+                                x, None, None, None)
+        self.assertRaisesRegexp(TypeError, r'^startswith\(', s.startswith,
+                                x, None, None, None)
+        self.assertRaisesRegexp(TypeError, r'^endswith\(', s.endswith,
+                                x, None, None, None)
+
 
 class MixinStrUnicodeTest:
     # Additional tests that only work with str and unicode.