From 822bebea46fae12d3acc622b7f55495f077e8b09 Mon Sep 17 00:00:00 2001
From: Greg Fitzgerald <greg@solana.com>
Date: Wed, 20 Feb 2019 15:36:10 -0700
Subject: [PATCH] Allow multiple forks without regenerating the hash

---
 runtime/src/bank.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index ecc517e42a..ed0d365990 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -105,8 +105,10 @@ impl Bank {
     pub fn new_from_parent(parent: &Arc<Bank>) -> Self {
         let mut bank = Self::default();
         bank.last_id_queue = RwLock::new(parent.last_id_queue.read().unwrap().clone());
-        *parent.hash.write().unwrap() = parent.hash_internal_state();
         bank.parent = Some(parent.clone());
+        if *parent.hash.read().unwrap() == Hash::default() {
+            *parent.hash.write().unwrap() = parent.hash_internal_state();
+        }
         bank
     }