From de6e5d3a94ef79b25b2036d4f02e229c5eddc822 Mon Sep 17 00:00:00 2001
From: Vito Tumas <5780819+Tapanito@users.noreply.github.com>
Date: Tue, 1 Sep 2026 13:51:39 +0000
Subject: [PATCH] fix: Keep VaultDeposit share count after the assetsTotal
 clamp (#8140)

---
 .../tx/transactors/vault/VaultDeposit.cpp     | 29 ++-----------------
 .../vault/VaultTransactorPrecision_test.cpp   |  9 ++++--
 2 files changed, 10 insertions(+), 28 deletions(-)

diff --git a/src/libxrpl/tx/transactors/vault/VaultDeposit.cpp b/src/libxrpl/tx/transactors/vault/VaultDeposit.cpp
index adb8b3f8f2..fc72159444 100644
--- a/src/libxrpl/tx/transactors/vault/VaultDeposit.cpp
+++ b/src/libxrpl/tx/transactors/vault/VaultDeposit.cpp
@@ -347,37 +347,14 @@ VaultDeposit::doApply()
         if (fix340Enabled)
         {
             // Round down at the posterior sfAssetsTotal scale so the vault is credited by no more
-            // than the depositor paid.
+            // than the depositor paid. Keep the share count from the first round trip: the clamp
+            // only drops a last digit of the new total. Converting the clamped amount back to
+            // shares would mint fewer shares while still charging the N-share debit.
             auto const maybeClamped = clampToAssetsTotalScale(vault, assetsDeposited);
             if (!maybeClamped)
                 return maybeClamped.error();
             assetsDeposited = *maybeClamped;
 
-            // The pre-clamp share count would over-issue by the trimmed ULP and give the depositor
-            // more value than they credited.
-            auto const maybeReShares = assetsToSharesDeposit(vault, sleIssuance, assetsDeposited);
-            if (!maybeReShares)
-                return tecINTERNAL;  // LCOV_EXCL_LINE
-
-            sharesCreated = *maybeReShares;
-
-            if (sharesCreated == beast::kZero)
-                return tecPRECISION_LOSS;
-
-            // The re-derived share count would over-issue if it round-trips back to more assets
-            // than the clamped amount actually paid. Unreachable unless a conversion helper is
-            // broken.
-            // LCOV_EXCL_START
-            auto const maybeReAssets = sharesToAssetsDeposit(vault, sleIssuance, sharesCreated);
-            if (!maybeReAssets)
-                return tecINTERNAL;
-            if (*maybeReAssets > assetsDeposited)
-            {
-                JLOG(j_.error()) << "VaultDeposit: would take more than offered.";
-                return tecINTERNAL;
-            }
-            // LCOV_EXCL_STOP
-
             // The actual deposit amount is truncated to whole shares, converted back to assets,
             // and clamped to the sfAssetsTotal scale (post-fixCleanup3_4_0). Check the depositor's
             // balance here—after clamping—before making any state changes.
diff --git a/src/test/app/vault/VaultTransactorPrecision_test.cpp b/src/test/app/vault/VaultTransactorPrecision_test.cpp
index e06c87ee68..8e8ee2d629 100644
--- a/src/test/app/vault/VaultTransactorPrecision_test.cpp
+++ b/src/test/app/vault/VaultTransactorPrecision_test.cpp
@@ -92,9 +92,14 @@ class VaultTransactorPrecision_test : public VaultPrecisionFixture
             if (before.sharesTotal == Number{0})
                 continue;
             Number const shareValue = (before.assetsTotal * sharesMinted) / before.sharesTotal;
+            // The depositor is never charged more than the shares they received are worth.
             BEAST_EXPECTS(
-                shareValue <= tDelta,
-                "amount=" + std::to_string(amount) + " shareValue > assetsTaken");
+                tDelta <= shareValue,
+                "amount=" + std::to_string(amount) + " assetsTaken > shareValue");
+            // Discount is strictly less than one ULP of the new AssetsTotal
+            BEAST_EXPECTS(
+                shareValue - tDelta < oneUnit(asset.raw(), after.assetsTotal),
+                "amount=" + std::to_string(amount) + " discount is not below one unit");
         }
 
         {