Prevent empty transactions from being added to vtxPrev

CWalletTx::AddSupportingTransactions() was adding empty transaction
to vtxPrev in some cases. Skip over these.

Part one of the solution to #3190. This prevents invalid vtxPrev from
entering the wallet, but not current ones being transmitted.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/wallet.cpp b/src/wallet.cpp
index a519c7a17f..1c5fb528ba 100644
--- a/src/wallet.cpp
+++ b/src/wallet.cpp
@@ -740,6 +740,10 @@ void CWalletTx::AddSupportingTransactions()
                 {
                     tx = *mapWalletPrev[hash];
                 }
+                else
+                {
+                    continue;
+                }
 
                 int nDepth = tx.SetMerkleBranch();
                 vtxPrev.push_back(tx);