diff -r 7255af1a1c50 Lib/test/string_tests.py
--- a/Lib/test/string_tests.py	Mon May 25 12:32:20 2015 +0300
+++ b/Lib/test/string_tests.py	Mon May 25 14:28:43 2015 +0300
@@ -976,6 +976,9 @@ class MixinStrUnicodeUserStringTest:
         self.checkequal(True, 'helloworld', 'startswith', 'lowo', 3)
         self.checkequal(True, 'helloworld', 'startswith', 'lowo', 3, 7)
         self.checkequal(False, 'helloworld', 'startswith', 'lowo', 3, 6)
+        self.checkequal(True, '', 'startswith', '', 0, 1)
+        self.checkequal(True, '', 'startswith', '', 0, 0)
+        self.checkequal(False, '', 'startswith', '', 1, 0)
 
         # test negative indices
         self.checkequal(True, 'hello', 'startswith', 'he', 0, -1)
@@ -1022,6 +1025,9 @@ class MixinStrUnicodeUserStringTest:
         self.checkequal(False, 'helloworld', 'endswith', 'lowo', 3, 8)
         self.checkequal(False, 'ab', 'endswith', 'ab', 0, 1)
         self.checkequal(False, 'ab', 'endswith', 'ab', 0, 0)
+        self.checkequal(True, '', 'endswith', '', 0, 1)
+        self.checkequal(True, '', 'endswith', '', 0, 0)
+        self.checkequal(False, '', 'endswith', '', 1, 0)
 
         # test negative indices
         self.checkequal(True, 'hello', 'endswith', 'lo', -2)
diff -r 7255af1a1c50 Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Mon May 25 12:32:20 2015 +0300
+++ b/Objects/unicodeobject.c	Mon May 25 14:28:43 2015 +0300
@@ -9280,14 +9280,14 @@ tailmatch(PyObject *self,
         PyUnicode_READY(substring) == -1)
         return -1;
 
-    if (PyUnicode_GET_LENGTH(substring) == 0)
-        return 1;
-
     ADJUST_INDICES(start, end, PyUnicode_GET_LENGTH(self));
     end -= PyUnicode_GET_LENGTH(substring);
     if (end < start)
         return 0;
 
+    if (PyUnicode_GET_LENGTH(substring) == 0)
+        return 1;
+
     kind_self = PyUnicode_KIND(self);
     data_self = PyUnicode_DATA(self);
     kind_sub = PyUnicode_KIND(substring);