From 2fd8e1be3c81ed816f3b808314b626c707a32d47 Mon Sep 17 00:00:00 2001
From: tequ <git@tequ.dev>
Date: Wed, 18 Feb 2026 15:55:10 +0900
Subject: [PATCH] audit 12

---
 .../Sponsor/SponsorshipTransfer.cpp           |  4 +-
 src/test/app/Sponsor_test.cpp                 | 49 +++++++++++++++++++
 2 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/src/libxrpl/tx/transactors/Sponsor/SponsorshipTransfer.cpp b/src/libxrpl/tx/transactors/Sponsor/SponsorshipTransfer.cpp
index 2d13c1c1f8..a11891d8c8 100644
--- a/src/libxrpl/tx/transactors/Sponsor/SponsorshipTransfer.cpp
+++ b/src/libxrpl/tx/transactors/Sponsor/SponsorshipTransfer.cpp
@@ -346,7 +346,7 @@ SponsorshipTransfer::doApply()
         else
         {
             // dissolve object sponsor
-            auto const oldSponsor = objSle->getAccountID(sfSponsor);
+            auto const oldSponsor = objSle->getAccountID(sponsorField);
             auto const oldSponsorSle = view().peek(keylet::account(oldSponsor));
             if (!oldSponsorSle)
                 return tefINTERNAL;  // LCOV_EXCL_LINE
@@ -367,7 +367,7 @@ SponsorshipTransfer::doApply()
                     return ter;
 
             // remove sponsor from object
-            objSle->makeFieldAbsent(sfSponsor);
+            objSle->makeFieldAbsent(sponsorField);
             view().update(objSle);
         }
     }
diff --git a/src/test/app/Sponsor_test.cpp b/src/test/app/Sponsor_test.cpp
index 6a619830f7..a40a56436f 100644
--- a/src/test/app/Sponsor_test.cpp
+++ b/src/test/app/Sponsor_test.cpp
@@ -873,6 +873,55 @@ public:
             BEAST_EXPECT(sponsor2Sle->getFieldU32(sfReserveCount) == 100);  // paybacked
         }
 
+        {
+            // sponsor trustline
+            Account const alice("alice");
+            Account const bob("bob");
+            Account const sponsor("sponsor");
+
+            auto const& highAcc = alice > bob ? alice : bob;
+            auto const& lowAcc = alice > bob ? bob : alice;
+
+            for (bool isIssuerHigh : {false, true})
+            {
+                Env env{*this, testable_amendments()};
+                env.fund(XRP(10000), alice, bob, sponsor);
+                env.close();
+
+                auto const& issuer = isIssuerHigh ? highAcc : lowAcc;
+                auto const& user = isIssuerHigh ? lowAcc : highAcc;
+
+                auto const USD = issuer["USD"];
+                auto const currency = USD.currency;
+
+                env(trust(user, issuer["USD"](100)));
+                env.close();
+
+                auto const trustId = keylet::line(user, issuer, currency);
+                BEAST_EXPECT(env.le(trustId));
+
+                // transfer sponsor
+                env(sponsor::transfer(user, trustId.key),
+                    sponsor::as(sponsor, tfSponsorReserve),
+                    sig(sfSponsorSignature, sponsor));
+                env.close();
+
+                BEAST_EXPECT(env.le(trustId));
+
+                BEAST_EXPECT(
+                    env.le(trustId)->getAccountID(isIssuerHigh ? sfLowSponsor : sfHighSponsor) == sponsor.id());
+                BEAST_EXPECT(!env.le(trustId)->isFieldPresent(isIssuerHigh ? sfHighSponsor : sfLowSponsor));
+
+                // dissolve sponsor
+                env(sponsor::transfer(user, trustId.key));
+                env.close();
+
+                BEAST_EXPECT(env.le(trustId));
+                BEAST_EXPECT(!env.le(trustId)->isFieldPresent(isIssuerHigh ? sfLowSponsor : sfHighSponsor));
+                BEAST_EXPECT(!env.le(trustId)->isFieldPresent(isIssuerHigh ? sfHighSponsor : sfLowSponsor));
+            }
+        }
+
         {
             // invalid transfer
             Env env{*this, testable_amendments()};