From 6cbf2e5f8197e51b8f3d789ba9f5874a2fd7b93a Mon Sep 17 00:00:00 2001
From: Martin Zumsande <mzumsande@gmail.com>
Date: Wed, 17 Jul 2024 13:23:52 -0400
Subject: [PATCH] rpc: Improve gettxoutproof error when only header is
 available.

---
 src/rpc/txoutproof.cpp            | 5 +++++
 test/functional/rpc_txoutproof.py | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/src/rpc/txoutproof.cpp b/src/rpc/txoutproof.cpp
index 7958deb6770..40294fda064 100644
--- a/src/rpc/txoutproof.cpp
+++ b/src/rpc/txoutproof.cpp
@@ -10,6 +10,7 @@
 #include <merkleblock.h>
 #include <node/blockstorage.h>
 #include <primitives/transaction.h>
+#include <rpc/blockchain.h>
 #include <rpc/server.h>
 #include <rpc/server_util.h>
 #include <rpc/util.h>
@@ -96,6 +97,10 @@ static RPCHelpMan gettxoutproof()
                 }
             }
 
+            {
+                LOCK(cs_main);
+                CheckBlockDataAvailability(chainman.m_blockman, *pblockindex, /*check_for_undo=*/false);
+            }
             CBlock block;
             if (!chainman.m_blockman.ReadBlockFromDisk(block, *pblockindex)) {
                 throw JSONRPCError(RPC_INTERNAL_ERROR, "Can't read block from disk");
diff --git a/test/functional/rpc_txoutproof.py b/test/functional/rpc_txoutproof.py
index 387132b6809..90572245d60 100755
--- a/test/functional/rpc_txoutproof.py
+++ b/test/functional/rpc_txoutproof.py
@@ -67,6 +67,10 @@ class MerkleBlockTest(BitcoinTestFramework):
         assert_equal(self.nodes[0].verifytxoutproof(self.nodes[0].gettxoutproof([txid_spent], blockhash)), [txid_spent])
         # We can't get the proof if we specify a non-existent block
         assert_raises_rpc_error(-5, "Block not found", self.nodes[0].gettxoutproof, [txid_spent], "0000000000000000000000000000000000000000000000000000000000000000")
+        # We can't get the proof if we only have the header of the specified block
+        block = self.generateblock(self.nodes[0], output="raw(55)", transactions=[], submit=False)
+        self.nodes[0].submitheader(block["hex"])
+        assert_raises_rpc_error(-1, "Block not available (not fully downloaded)", self.nodes[0].gettxoutproof, [txid_spent], block['hash'])
         # We can get the proof if the transaction is unspent
         assert_equal(self.nodes[0].verifytxoutproof(self.nodes[0].gettxoutproof([txid_unspent])), [txid_unspent])
         # We can get the proof if we provide a list of transactions and one of them is unspent. The ordering of the list should not matter.