From a7f9365fb8686175c14a8c4616e9509e7772ccd6 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Wed, 18 Nov 2020 11:12:09 +0000
Subject: [PATCH] test: Set hashFinalSaplingRoot default correctly in
 create_block

---
 qa/rpc-tests/test_framework/blocktools.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/qa/rpc-tests/test_framework/blocktools.py b/qa/rpc-tests/test_framework/blocktools.py
index 123ef5bdf..d3f06f479 100644
--- a/qa/rpc-tests/test_framework/blocktools.py
+++ b/qa/rpc-tests/test_framework/blocktools.py
@@ -16,8 +16,10 @@ def create_block(hashprev, coinbase, nTime=None, nBits=None, hashFinalSaplingRoo
     else:
         block.nTime = nTime
     block.hashPrevBlock = hashprev
-    if hashFinalSaplingRoot is not None:
-        block.hashFinalSaplingRoot = hashFinalSaplingRoot
+    if hashFinalSaplingRoot is None:
+        # By default NUs up to Sapling are active from block 1, so we set this to the empty root.
+        hashFinalSaplingRoot = 0x3e49b5f954aa9d3545bc6c37744661eea48d7c34e3000d82b7f0010c30f4c2fb
+    block.hashFinalSaplingRoot = hashFinalSaplingRoot
     if nBits is None:
         block.nBits = 0x200f0f0f # difficulty retargeting is disabled in REGTEST chainparams
     else: