message: mininode: Allow to specify explicitly whether to send zero checksums
diff: @@ -274,6 +274,7 @@ class NodeConn(asyncore.dispatcher):
  self.disconnect = False
  self.curIndex = 0
  self.allow0Checksum = False
  + self.produce0Checksum = False
  self.num0Checksums = 0
  if send_initial_version:
  # stuff version msg into sendbuf
  @@ -420,6 +421,9 @@ class NodeConn(asyncore.dispatcher):
  tmsg += b"\x00" * (12 - len(command))
  tmsg += struct.pack("<I", len(data))
  if self.ver_send >= 209:
  + if self.produce0Checksum:
  + tmsg += b"\x00" * 4
  + else:
  th = sha256(data)
  h = sha256(th)
  tmsg += h[:4]
  