From b90215dda1c086c7c288ac9d7e3d75e0516f0fd5 Mon Sep 17 00:00:00 2001
From: Eugene Crosser <crosser@average.org>
Date: Sat, 29 Mar 2014 23:19:38 +0400
Subject: [PATCH] handle empty 'value' as domain with no data

---
 NmcJson.hs       | 9 +++++++--
 pdns-pipe-nmc.hs | 9 ++++++---
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/NmcJson.hs b/NmcJson.hs
index 978fb04..651aa46 100644
--- a/NmcJson.hs
+++ b/NmcJson.hs
@@ -2,6 +2,7 @@
 
 module NmcJson  ( NmcRes(..)
                 , NmcDom
+                , emptyNmcDom
                 ) where
 
 import Data.ByteString.Lazy (ByteString)
@@ -28,7 +29,7 @@ instance FromJSON NmcRRService where
                 <*> o .: "host"
         parseJSON _ = empty
 
-data NmcRRI2p = NmcRRI2p -- unused
+data NmcRRI2p = NmcRRI2p
                         { i2pDestination :: String
                         , i2pName        :: String
                         , i2pB32         :: String
@@ -84,8 +85,12 @@ instance FromJSON NmcDom where
                 <*> o .:? "ds"
         parseJSON _ = empty
 
+emptyNmcDom = NmcDom Nothing Nothing Nothing Nothing Nothing Nothing
+                     Nothing Nothing Nothing Nothing Nothing Nothing
+                     Nothing Nothing Nothing Nothing Nothing Nothing
+
 data NmcRes = NmcRes    { resName       :: String
-                        , resValue      :: ByteString -- NmcDom
+                        , resValue      :: ByteString -- string with NmcDom
                         , resTxid       :: String
                         , resAddress    :: String
                         , resExpires_in :: Int
diff --git a/pdns-pipe-nmc.hs b/pdns-pipe-nmc.hs
index ee5bd37..9e4a729 100644
--- a/pdns-pipe-nmc.hs
+++ b/pdns-pipe-nmc.hs
@@ -43,9 +43,12 @@ qRsp rsp =
     case parseJsonRpc (responseBody rsp) :: Either JsonRpcError NmcRes of
       Left  jerr -> Left $ "Unparseable response: " ++ (show (responseBody rsp))
       Right jrsp ->
-        case decode (resValue jrsp) :: Maybe NmcDom of
-          Nothing  -> Left $ "Unparseable value: " ++ (show (resValue jrsp))
-          Just dom -> Right dom
+        case resValue jrsp of
+          "" -> Right emptyNmcDom
+          vstr ->
+            case decode vstr :: Maybe NmcDom of
+              Nothing  -> Left $ "Unparseable value: " ++ (show vstr)
+              Just dom -> Right dom
 
 -- NMC interface
 
-- 
2.39.2