From 8cbd09438c5394bd331782043affcfc34de1306c Mon Sep 17 00:00:00 2001
From: Andreas Schildbach <andreas@schildbach.de>
Date: Mon, 10 Mar 2025 11:17:28 +0100
Subject: [PATCH] StoredBlock: if getPrev() called on a genesis block, cut
 short

Don't try to locate a previous block of the genesis block, using
an arbitrary "previous block hash".
---
 core/src/main/java/org/bitcoinj/core/StoredBlock.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/core/src/main/java/org/bitcoinj/core/StoredBlock.java b/core/src/main/java/org/bitcoinj/core/StoredBlock.java
index b79573c33..4719778b4 100644
--- a/core/src/main/java/org/bitcoinj/core/StoredBlock.java
+++ b/core/src/main/java/org/bitcoinj/core/StoredBlock.java
@@ -129,7 +129,9 @@ public class StoredBlock {
      * @return the previous block in the chain or null if it was not found in the store.
      */
     public StoredBlock getPrev(BlockStore store) throws BlockStoreException {
-        return store.get(getHeader().getPrevBlockHash());
+        return height > 0 ?
+                store.get(header.getPrevBlockHash()) :
+                null; // Genesis blocks have no previous block.
     }
 
     /**