From 8a6d2da5c911b3f63426c9e5331c55a36c27befc Mon Sep 17 00:00:00 2001
From: Craig Raw <craigraw@gmail.com>
Date: Mon, 25 Jul 2022 14:46:54 +0200
Subject: [PATCH] disallow duplicate xpubs in multisig wallet keystores

---
 .../java/com/sparrowwallet/drongo/wallet/Wallet.java | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java b/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
index 76eff7e..fe48d3e 100644
--- a/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
+++ b/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
@@ -1710,6 +1710,10 @@ public class Wallet extends Persistable implements Comparable<Wallet> {
                 throw new InvalidWalletException("Keystore " + keystore.getLabel() + " derivation of " + keystore.getKeyDerivation().getDerivationPath() + " in " + scriptType.getName() + " wallet matches another default script type.");
             }
         }
+
+        if(containsDuplicateExtendedKeys()) {
+            throw new InvalidWalletException("Wallet keystores have duplicate extended public keys");
+        }
     }
 
     public boolean derivationMatchesAnotherScriptType(String derivationPath) {
@@ -1732,6 +1736,14 @@ public class Wallet extends Persistable implements Comparable<Wallet> {
         return !keystores.stream().map(Keystore::getLabel).allMatch(new HashSet<>()::add);
     }
 
+    public boolean containsDuplicateExtendedKeys() {
+        if(keystores.size() <= 1) {
+            return false;
+        }
+
+        return !keystores.stream().map(Keystore::getExtendedPublicKey).allMatch(new HashSet<>()::add);
+    }
+
     public void makeLabelsUnique(Keystore newKeystore) {
         makeLabelsUnique(newKeystore, false);
     }