From 12c17252602773430ba8072ef0d704d168507438 Mon Sep 17 00:00:00 2001
From: Craig Raw <craigraw@gmail.com>
Date: Tue, 6 Dec 2022 11:22:35 +0200
Subject: [PATCH] fix edge case when loading wallets with matching tx inputs
 and outputs

---
 .../sparrow/io/db/WalletNodeReducer.java           | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/sparrowwallet/sparrow/io/db/WalletNodeReducer.java b/src/main/java/com/sparrowwallet/sparrow/io/db/WalletNodeReducer.java
index 6c28312a..0daf7594 100644
--- a/src/main/java/com/sparrowwallet/sparrow/io/db/WalletNodeReducer.java
+++ b/src/main/java/com/sparrowwallet/sparrow/io/db/WalletNodeReducer.java
@@ -1,5 +1,6 @@
 package com.sparrowwallet.sparrow.io.db;
 
+import com.sparrowwallet.drongo.protocol.Sha256Hash;
 import com.sparrowwallet.drongo.wallet.BlockTransactionHashIndex;
 import com.sparrowwallet.drongo.wallet.WalletNode;
 import org.jdbi.v3.core.result.LinkedHashMapRowReducer;
@@ -8,6 +9,8 @@ import org.jdbi.v3.core.result.RowView;
 import java.util.Map;
 
 public class WalletNodeReducer implements LinkedHashMapRowReducer<Long, WalletNode> {
+    private static final BlockTransactionHashIndex INPUT_MARKER = new BlockTransactionHashIndex(Sha256Hash.ZERO_HASH, 0, null, null, 0, 0);
+
     @Override
     public void accumulate(Map<Long, WalletNode> map, RowView rowView) {
         WalletNode walletNode = map.computeIfAbsent(rowView.getColumn("walletNode.id", Long.class), id -> rowView.getRow(WalletNode.class));
@@ -20,11 +23,18 @@ public class WalletNodeReducer implements LinkedHashMapRowReducer<Long, WalletNo
         if(rowView.getColumn("blockTransactionHashIndex.node", Long.class) != null) {
             BlockTransactionHashIndex blockTransactionHashIndex = rowView.getRow(BlockTransactionHashIndex.class);
             if(rowView.getColumn("blockTransactionHashIndex.spentBy", Long.class) != null) {
-                BlockTransactionHashIndex spentBy = walletNode.getTransactionOutputs().stream().filter(ref -> ref.getId().equals(rowView.getColumn("blockTransactionHashIndex.spentBy", Long.class))).findFirst().orElseThrow();
+                BlockTransactionHashIndex spentBy = walletNode.getTransactionOutputs().stream().filter(ref -> ref.getId().equals(rowView.getColumn("blockTransactionHashIndex.spentBy", Long.class))).findFirst()
+                        .orElseThrow(() -> new IllegalStateException("Cannot find transaction output for " + rowView.getColumn("blockTransactionHashIndex.spentBy", Long.class)));
                 blockTransactionHashIndex.setSpentBy(spentBy);
                 walletNode.getTransactionOutputs().remove(spentBy);
+                spentBy.setSpentBy(null);
+            }
+            if(!walletNode.getTransactionOutputs().add(blockTransactionHashIndex)) {
+                //Can only happen if we add an input with the same hash, index, height etc as an existing output
+                //Set a marker we will clear when adding the output
+                blockTransactionHashIndex.setSpentBy(INPUT_MARKER);
+                walletNode.getTransactionOutputs().add(blockTransactionHashIndex);
             }
-            walletNode.getTransactionOutputs().add(blockTransactionHashIndex);
         }
     }
 }