From 52e7cdc24dbc0448907e2167b16b0e3e7cf1734e Mon Sep 17 00:00:00 2001
From: tequ <git@tequ.dev>
Date: Tue, 21 Apr 2026 13:48:07 +0900
Subject: [PATCH] fix: Sponsored account creation double-counts base reserve
 #6894

---
 .../tx/transactors/payment/Payment.cpp        |  3 +--
 src/test/app/Sponsor_test.cpp                 | 24 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/libxrpl/tx/transactors/payment/Payment.cpp b/src/libxrpl/tx/transactors/payment/Payment.cpp
index 4475bbd761..81f0b06dc2 100644
--- a/src/libxrpl/tx/transactors/payment/Payment.cpp
+++ b/src/libxrpl/tx/transactors/payment/Payment.cpp
@@ -611,8 +611,7 @@ Payment::doApply()
 
     // the number of reserves in this ledger for this account that require a
     // reserve.
-    auto const reserve = calculateReserve(sleSrc, view().fees()) +
-        (((txFlags & tfSponsorCreatedAccount) != 0u) ? view().fees().reserve : beast::zero);
+    auto const reserve = calculateReserve(sleSrc, view().fees());
 
     // In a delegated payment, the fee payer is the delegated account,
     // not the source account (account_).
diff --git a/src/test/app/Sponsor_test.cpp b/src/test/app/Sponsor_test.cpp
index 41b5e88b65..3cbb4d16fa 100644
--- a/src/test/app/Sponsor_test.cpp
+++ b/src/test/app/Sponsor_test.cpp
@@ -1710,8 +1710,10 @@ public:
         Account const alice("alice");
         Account const sponsor("sponsor");
         Account const sponsor2("sponsor2");
+        Account const sponsor3("sponsor3");
         Account const bob("bob");
         Account const charlie("charlie");
+        Account const dave("dave");
         Account const gw("gw");
         auto const USD = gw["USD"];
 
@@ -1725,7 +1727,7 @@ public:
         }
 
         Env env{*this, testable_amendments()};
-        env.fund(XRP(10000), alice, sponsor, sponsor2);
+        env.fund(XRP(10000), alice, sponsor, sponsor2, sponsor3);
         env.close();
 
         // Invalid flags
@@ -1788,6 +1790,26 @@ public:
             // verify sponsor balance decreased by payment + fee
             BEAST_EXPECT(env.balance(sponsor2) == sponsor2BalanceBefore - drops(1) - XRP(1));
         }
+        {
+            // insufficient reserve to sponsor acount
+
+            auto const sendAmount = drops(1);
+            // 2 account reserve + send amount
+            auto const requireBalance = accountReserve(env, 2) + sendAmount;
+            adjustAccountXRPBalance(env, sponsor3, requireBalance - drops(1));
+            env(pay(sponsor3, dave, sendAmount),
+                txflags(tfSponsorCreatedAccount),
+                fee(XRP(1)),
+                ter(tecUNFUNDED_PAYMENT));
+            env.close();
+
+            adjustAccountXRPBalance(env, sponsor3, requireBalance);
+            env(pay(sponsor3, dave, sendAmount),
+                txflags(tfSponsorCreatedAccount),
+                fee(XRP(1)),
+                ter(tesSUCCESS));
+            env.close();
+        }
     }
 
     void