clone: don't include empty revlogs in stream

mercurial/wireproto.py

@@ -545,6 +545,7 def stream(repo, proto):
         try:
             repo.ui.debug('scanning\n')
             for name, ename, size in repo.store.walk():
+                if size:
                 entries.append((name, size))
                 total_bytes += size
         finally: