From b75b9f2a7181198a5f10d6e933b050ecd1cd3175 Mon Sep 17 00:00:00 2001
From: Richard Holland <richard.holland@starstone.co.nz>
Date: Mon, 20 Feb 2023 11:17:13 +0000
Subject: [PATCH] fix for #24

---
 src/ripple/app/hook/impl/applyHook.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/ripple/app/hook/impl/applyHook.cpp b/src/ripple/app/hook/impl/applyHook.cpp
index a5fbc74dd..73947ce80 100644
--- a/src/ripple/app/hook/impl/applyHook.cpp
+++ b/src/ripple/app/hook/impl/applyHook.cpp
@@ -3168,13 +3168,19 @@ DEFINE_HOOK_FUNCTION(
     }
 
     // rule 5: LastLedgerSeq must be present and after current ledger
+    if (!stpTrans->isFieldPresent(sfLastLedgerSequence))
+    {
+        JLOG(j.trace())
+            << "HookEmit[" << HC_ACC() << "]: sfLastLedgerSequence missing";
+        return EMISSION_FAILURE;
+    }
 
     uint32_t tx_lls = stpTrans->getFieldU32(sfLastLedgerSequence);
     uint32_t ledgerSeq = applyCtx.app.getLedgerMaster().getValidLedgerIndex() + 1;
-    if (!stpTrans->isFieldPresent(sfLastLedgerSequence) || tx_lls < ledgerSeq + 1)
+    if (tx_lls < ledgerSeq + 1)
     {
         JLOG(j.trace())
-            << "HookEmit[" << HC_ACC() << "]: sfLastLedgerSequence missing or invalid";
+            << "HookEmit[" << HC_ACC() << "]: sfLastLedgerSequence invalid (less than next ledger)";
         return EMISSION_FAILURE;
     }