From 0736fa14fccddaab949cf3114ce9075341624e01 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Wed, 31 Aug 2016 21:16:59 +1200
Subject: [PATCH] Keep any existing cached witnesses when updating transactions

---
 src/wallet/wallet.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index fe2771e66..438de40db 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -917,7 +917,16 @@ bool CWallet::AddToWallet(const CWalletTx& wtxIn, bool fFromLoadWallet, CWalletD
             }
             if (!wtxIn.mapNoteData.empty() && wtxIn.mapNoteData != wtx.mapNoteData)
             {
-                wtx.mapNoteData = wtxIn.mapNoteData;
+                auto tmp = wtxIn.mapNoteData;
+                // Ensure we keep any cached witnesses we may already have
+                for (const std::pair<JSOutPoint, CNoteData> nd : wtx.mapNoteData) {
+                    if (tmp.count(nd.first) && nd.second.witnesses.size() > 0) {
+                        tmp.at(nd.first).witnesses.assign(
+                            nd.second.witnesses.cbegin(), nd.second.witnesses.cend());
+                    }
+                }
+                // Now copy over the updated note data
+                wtx.mapNoteData = tmp;
                 fUpdated = true;
             }
             if (wtxIn.fFromMe && wtxIn.fFromMe != wtx.fFromMe)