diff -r 9f41b66cffc0 -r 9626022feaa4 mercurial/bundle2.py
--- a/mercurial/bundle2.py	Sat Oct 15 15:01:14 2016 -0700
+++ b/mercurial/bundle2.py	Sat Oct 15 17:10:53 2016 -0700
@@ -573,7 +573,9 @@
             yield param
         # starting compression
         for chunk in self._getcorechunk():
-            yield self._compressor.compress(chunk)
+            data = self._compressor.compress(chunk)
+            if data:
+                yield data
         yield self._compressor.flush()
 
     def _paramchunk(self):
@@ -1324,7 +1326,9 @@
         def chunkiter():
             yield header
             for chunk in subchunkiter:
-                yield z.compress(chunk)
+                data = z.compress(chunk)
+                if data:
+                    yield data
             yield z.flush()
         chunkiter = chunkiter()