Merge pull request #2399 from fluetm/build-index-url-fix

Correct INDEX_URL logic in build.py _set_auth_headers

Author: shin-

docker/api/build.py

@@ -308,7 +308,8 @@ def _set_auth_headers(self, headers):
             auth_data = self._auth_configs.get_all_credentials()
 
             # See https://github.com/docker/docker-py/issues/1683
-            if auth.INDEX_URL not in auth_data and auth.INDEX_URL in auth_data:
+            if (auth.INDEX_URL not in auth_data and
+                    auth.INDEX_NAME in auth_data):
                 auth_data[auth.INDEX_URL] = auth_data.get(auth.INDEX_NAME, {})
 
             log.debug(