file size can be zero

src/python/dm/common/processing/plugins/gridftpFileTransferPlugin.py

@@ -69,7 +69,7 @@ class GridftpFileTransferPlugin(FileTransferPlugin):
             # Check size
             fSize = filePathDict.get('fileSize') 
             sfSize = storageFilePathDict.get('fileSize') 
-            if not fSize or not sfSize or fSize != sfSize:
+            if fSize is None or sfSize is None or fSize != sfSize:
                 # Sizes differ, need to transfer file
                 continue