# HG changeset patch
# User Gregory Szorc <gregory.szorc@gmail.com>
# Date 2018-10-05 23:49:18
# Node ID 3a6d6c54bd81eb46aa7be295c3ae4c977a4e9b37
# Parent  966b5f7fd30bf2d6a99c0c3e6253e442868d6e31

wireprotov2: don't emit empty frames

Staring at logs revealed the presence of empty frames that should have
contained payload. Let's stop that from happening.

Differential Revision: https://phab.mercurial-scm.org/D4925

diff --git a/mercurial/wireprotoframing.py b/mercurial/wireprotoframing.py
--- a/mercurial/wireprotoframing.py
+++ b/mercurial/wireprotoframing.py
@@ -531,6 +531,9 @@ class bufferingcommandresponseemitter(ob
         # * If a chunk causes us to go over our buffering limit, we flush
         #   and then buffer the new chunk.
 
+        if not data:
+            return
+
         if len(data) > self._maxsize:
             for frame in self._flush():
                 yield frame
@@ -573,6 +576,9 @@ class bufferingcommandresponseemitter(ob
         self._chunks[:] = []
         self._chunkssize = 0
 
+        if not payload:
+            return
+
         yield self._stream.makeframe(
             self._requestid,
             typeid=FRAME_TYPE_COMMAND_RESPONSE,
diff --git a/tests/test-wireproto-serverreactor.py b/tests/test-wireproto-serverreactor.py
--- a/tests/test-wireproto-serverreactor.py
+++ b/tests/test-wireproto-serverreactor.py
@@ -394,7 +394,6 @@ class ServerReactorTests(unittest.TestCa
             b'1 2 0 command-response continuation Y\x80d',
             b'1 2 0 command-response continuation %s' % first,
             b'1 2 0 command-response continuation %s' % second,
-            b'1 2 0 command-response continuation ',
             b'1 2 0 command-response eos '
         ])