Allow unknown packages without payload

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 0.20.2
+### Fixed
+- Allow unknown messages of zero length.
+
 ## 0.20.1
 ### Fixed
 - Correct case where binary search returned the wrong element.

haskoin-core.cabal

@@ -4,10 +4,10 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 453f8e3571726d6b8f4955298154df7bc915f395fe414b2b3c859021583dfbfe
+-- hash: 460dd0e8508262fb1b685467ea87f00e9793d37026ca63ec280adc2699d21810
 
 name:           haskoin-core
-version:        0.20.1
+version:        0.20.2
 synopsis:       Bitcoin & Bitcoin Cash library for Haskell
 description:    Please see the README on GitHub at <https://github.com/haskoin/haskoin-core#readme>
 category:       Bitcoin, Finance, Network

package.yaml

@@ -1,5 +1,5 @@
 name: haskoin-core
-version: 0.20.1
+version: 0.20.2
 synopsis: Bitcoin & Bitcoin Cash library for Haskell
 description: Please see the README on GitHub at <https://github.com/haskoin/haskoin-core#readme>
 category: Bitcoin, Finance, Network

src/Haskoin/Network/Message.hs

@@ -175,6 +175,7 @@ getMessage net = do
                  MCFilterClear -> return MFilterClear
                  MCMempool     -> return MMempool
                  MCSendHeaders -> return MSendHeaders
+                 MCOther c     -> return (MOther c BS.empty)
                  _             -> fail $ "get: command " ++ show cmd ++
                                          " is expected to carry a payload"