From da502076bd4600c712fd5f8a0ba7533619b4a72c Mon Sep 17 00:00:00 2001
From: ThomasV <thomasv@gitorious>
Date: Mon, 30 Mar 2015 20:39:06 +0200
Subject: [PATCH] fix get_history

---
 lib/wallet.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/wallet.py b/lib/wallet.py
index b5cc0836..7646a15b 100644
--- a/lib/wallet.py
+++ b/lib/wallet.py
@@ -738,7 +738,7 @@ class Abstract_Wallet(object):
                 merged[tx_hash] = (height, delta)
             else:
                 h, d = merged.get(tx_hash)
-                merged[tx_hash] = (h, d + delta)
+                merged[tx_hash] = (h, d + delta if (d is not None and delta is not None) else None)
 
         # 3. create sorted list
         history = []