WeedFS cannot store 0-length files
Merge commit '21ebc6d43a54b482b8e382f166c445521d03d087'
Merge commit 'a90c4f1b6924ab4d99b8535861c8c5f72eb1c135'
Merge commit 'b19e89ccdcf91b972a4160ae81456acf548282e2'