Don't use default value in LimitingReader

We can't simply pass the None default on to the read operation as this
default is handled differently between different wsgi implementations.

Change-Id: I337e797b8dee3dfcf9299fe361cf197a176c8fe2
Fixes: bug 1213106

keystone/common/utils.py

@@ -290,7 +290,12 @@ class LimitingReader(object):
                 yield chunk
 
     def read(self, i=None):
-        result = self.data.read(i)
+        # NOTE(jamielennox): We can't simply provide the default to the read()
+        # call as the expected default differs between mod_wsgi and eventlet
+        if i is None:
+            result = self.data.read()
+        else:
+            result = self.data.read(i)
         self.bytes_read += len(result)
         if self.bytes_read > self.limit:
             raise exception.RequestTooLarge()

keystone/tests/test_utils.py

@@ -105,3 +105,26 @@ class UtilsTestCase(tests.TestCase):
         for d in ['+0', '-11', '-8', '-5', '+5', '+8', '+14']:
             TZ = 'UTC' + d
             _test_unixtime()
+
+
+class LimitingReaderTests(tests.TestCase):
+
+    def test_read_default_value(self):
+
+        class FakeData(object):
+            def read(self, *args, **kwargs):
+                self.read_args = args
+                self.read_kwargs = kwargs
+                return 'helloworld'
+
+        data = FakeData()
+        utils.LimitingReader(data, 100)
+
+        self.assertEqual(data.read(), 'helloworld')
+        self.assertEqual(len(data.read_args), 0)
+        self.assertEqual(len(data.read_kwargs), 0)
+
+        self.assertEqual(data.read(10), 'helloworld')
+        self.assertEqual(len(data.read_args), 1)
+        self.assertEqual(len(data.read_kwargs), 0)
+        self.assertEqual(data.read_args[0], 10)