Handle empty request body with chunked encoding

* Identify and handle requests with empty body
  and 'transfer-encoding' request header
  set to value 'chunked'

Change-Id: I54462dad76bdbf7c069ae3031237d98702a77e40
Closes-Bug: #1249501

glance/common/wsgi.py

@@ -571,13 +571,18 @@ class Request(webob.Request):
 
 
 class JSONRequestDeserializer(object):
+    valid_transfer_encoding = frozenset(['chunked', 'compress', 'deflate',
+                                         'gzip', 'identity'])
+
     def has_body(self, request):
         """
         Returns whether a Webob.Request object will possess an entity body.
 
         :param request:  Webob.Request object
         """
-        if 'transfer-encoding' in request.headers:
+        request_encoding = request.headers.get('transfer-encoding', '').lower()
+        is_valid_encoding = request_encoding in self.valid_transfer_encoding
+        if is_valid_encoding and request.is_body_readable:
             return True
         elif request.content_length > 0:
             return True

glance/tests/unit/common/test_rpc.py

@@ -344,7 +344,7 @@ class TestRPCJSONDeserializer(test_utils.BaseTestCase):
         request = wsgi.Request.blank('/')
         request.method = 'POST'
         request.body = 'fake_body'
-        request.headers['transfer-encoding'] = 0
+        request.headers['transfer-encoding'] = ''
         self.assertIn('transfer-encoding', request.headers)
         self.assertTrue(rpc.RPCJSONDeserializer().has_body(request))
 

glance/tests/unit/common/test_wsgi.py

@@ -447,12 +447,35 @@ class JSONRequestDeserializerTest(test_utils.BaseTestCase):
         self.assertEqual(expected, actual)
 
     def test_has_body_has_transfer_encoding(self):
+        self.assertTrue(self._check_transfer_encoding(
+                        transfer_encoding='chunked'))
+
+    def test_has_body_multiple_transfer_encoding(self):
+        self.assertTrue(self._check_transfer_encoding(
+                        transfer_encoding='chunked, gzip'))
+
+    def test_has_body_invalid_transfer_encoding(self):
+        self.assertFalse(self._check_transfer_encoding(
+                         transfer_encoding='invalid', content_length=0))
+
+    def test_has_body_invalid_transfer_encoding_with_content_length(self):
+        self.assertTrue(self._check_transfer_encoding(
+                        transfer_encoding='invalid', content_length=5))
+
+    def test_has_body_valid_transfer_encoding_with_content_length(self):
+        self.assertTrue(self._check_transfer_encoding(
+                        transfer_encoding='chunked', content_length=0))
+
+    def _check_transfer_encoding(self, transfer_encoding=None,
+                                 content_length=None):
         request = wsgi.Request.blank('/')
         request.method = 'POST'
         request.body = 'fake_body'
-        request.headers['transfer-encoding'] = 0
-        self.assertIn('transfer-encoding', request.headers)
-        self.assertTrue(wsgi.JSONRequestDeserializer().has_body(request))
+        request.headers['transfer-encoding'] = transfer_encoding
+        if content_length is not None:
+            request.headers['content-length'] = content_length
+
+        return wsgi.JSONRequestDeserializer().has_body(request)
 
     def test_get_bind_addr_default_value(self):
         expected = ('0.0.0.0', '123456')