Fix the final boundary in resumable multipart media uploads.

Reviewed in http://codereview.appspot.com/5450107/.

apiclient/http.py

@@ -251,7 +251,9 @@ class HttpRequest(object):
     # Pull the multipart boundary out of the content-type header.
     major, minor, params = mimeparse.parse_mime_type(
         headers.get('content-type', 'application/json'))
-    self.multipart_boundary = params.get('boundary', '').strip('"')
+
+    # Terminating multipart boundary get a trailing '--' appended.
+    self.multipart_boundary = params.get('boundary', '').strip('"') + '--'
 
     # If this was a multipart resumable, the size of the non-media part.
     self.multipart_size = 0

oauth2client/client.py

@@ -754,6 +754,8 @@ if HAS_OPENSSL:
 
 
 def _urlsafe_b64decode(b64string):
+  # Guard against unicode strings, which base64 can't handle.
+  b64string = b64string.encode('ascii')
   padded = b64string + '=' * (4 - len(b64string) % 4)
   return base64.urlsafe_b64decode(padded)
 

oauth2client/crypt.py

@@ -137,6 +137,8 @@ def _urlsafe_b64encode(raw_bytes):
 
 
 def _urlsafe_b64decode(b64string):
+  # Guard against unicode strings, which base64 can't handle.
+  b64string = b64string.encode('ascii')
   padded = b64string + '=' * (4 - len(b64string) % 4)
   return base64.urlsafe_b64decode(padded)
 

tests/test_discovery.py

@@ -389,7 +389,7 @@ class Discovery(unittest.TestCase):
 
     self.assertEquals('image/png', request.resumable.mimetype())
 
-    self.assertEquals(request.multipart_boundary, '')
+    self.assertEquals(request.multipart_boundary, '--')
     self.assertEquals(request.body, None)
     self.assertEquals(request.resumable_uri, None)
 

tests/test_http.py

@@ -109,7 +109,7 @@ class TestUserAgent(unittest.TestCase):
     self.assertEquals(new_req.body, '{}')
     self.assertEquals(new_req.http, http)
     self.assertEquals(new_req.resumable.to_json(), media_upload.to_json())
-    self.assertEquals(new_req.multipart_boundary, '---flubber')
+    self.assertEquals(new_req.multipart_boundary, '---flubber--')
 
 EXPECTED = """POST /someapi/v1/collection/?foo=bar HTTP/1.1
 Content-Type: application/json

tests/test_oauth2client.py

@@ -280,7 +280,8 @@ class OAuth2WebServerFlowTest(unittest.TestCase):
   def test_exchange_id_token_fail(self):
     body = {'foo': 'bar'}
     payload = base64.urlsafe_b64encode(simplejson.dumps(body)).strip('=')
-    jwt = 'stuff.' + payload + '.signature'
+    jwt = (base64.urlsafe_b64encode('stuff')+ '.' + payload + '.' +
+           base64.urlsafe_b64encode('signature'))
 
     http = HttpMockSequence([
       ({'status': '200'}, """{ "access_token":"SlAV32hkKG",