Merge branch 'ximinez/lending-XLS-66-ongoing' into ximinez/lending-vault-payments

* XRPLF/ximinez/lending-XLS-66:
  Review feedback from @shawnxie999: MPT Clawback
  Move the ValidPseudoAccounts class back to its original location
  Fix formatting again
  refactor: Retire Flow and FlowSortStrands amendments (6054)
  Add additional documentation to Lending Protocol (6037)

src/libxrpl/ledger/View.cpp

@@ -3176,6 +3176,24 @@ requireAuth(
                 !isTesSuccess(err))
                 return err;
         }
+
+        // requireAuth is also recursive if the _account_ is a vault
+        auto const sleAccount = view.read(keylet::account(account));
+        if (!sleAccount)
+            return tefINTERNAL;  // LCOV_EXCL_LINE
+
+        if (sleAccount->isFieldPresent(sfVaultID))
+        {
+            auto const sleVault =
+                view.read(keylet::vault(sleAccount->getFieldH256(sfVaultID)));
+            if (!sleVault)
+                return tefINTERNAL;  // LCOV_EXCL_LINE
+            auto const ownerAcct = sleVault->getAccountID(sfOwner);
+            if (auto const err =
+                    requireAuth(view, mptIssue, ownerAcct, authType, depth + 1);
+                !isTesSuccess(err))
+                return err;
+        }
     }
 
     auto const mptokenID = keylet::mptoken(mptID.key, account);

src/test/app/Loan_test.cpp

@@ -2738,12 +2738,8 @@ protected:
                             broker.params.managementFeeRate);
 
                     BEAST_EXPECT(
-                        paymentComponents.trackedValueDelta ==
-                            roundedPeriodicPayment ||
-                        (paymentComponents.specialCase ==
-                             detail::PaymentSpecialCase::final &&
-                         paymentComponents.trackedValueDelta <
-                             roundedPeriodicPayment));
+                        paymentComponents.trackedValueDelta <=
+                        roundedPeriodicPayment);
 
                     ripple::LoanState const nextTrueState = computeRawLoanState(
                         state.periodicPayment,

src/test/app/Vault_test.cpp

@@ -2358,6 +2358,18 @@ class Vault_test : public beast::unit_test::suite
                      .amount = asset(100)});
                 env(tx, ter(tecNO_AUTH));
 
+                // Withdrawal to other (authorized) accounts doesn't work.
+                // Issuer would have to VaultClawback
+                tx[sfDestination] = issuer.human();
+                env(tx, ter(tecNO_AUTH));
+                tx[sfDestination] = owner.human();
+                env(tx, ter(tecNO_AUTH));
+                env.close();
+
+                // Issuer reauthorizes
+                mptt.authorize({.account = issuer, .holder = depositor});
+                env.close();
+
                 // Withdrawal to other (authorized) accounts works
                 tx[sfDestination] = issuer.human();
                 env(tx);
@@ -2368,6 +2380,13 @@ class Vault_test : public beast::unit_test::suite
                 env.close();
             }
 
+            // Re-unauthorize
+            mptt.authorize(
+                {.account = issuer,
+                 .holder = depositor,
+                 .flags = tfMPTUnauthorize});
+            env.close();
+
             {
                 // Cannot deposit some more
                 auto tx = vault.deposit(

src/xrpld/app/misc/detail/LendingHelpers.cpp

@@ -1075,23 +1075,6 @@ computePaymentComponents(
             "ripple::detail::computePaymentComponents",
             "excess non-negative");
     };
-    auto giveTo =
-        [](Number& component, Number& shortage, Number const& maximum) {
-            if (shortage > beast::zero)
-            {
-                // Put as much of the shortage as we can into the provided part
-                // and the total
-                auto part = std::min(maximum - component, shortage);
-                component += part;
-                shortage -= part;
-            }
-            // If the shortage goes negative, we put too much, which should be
-            // impossible
-            XRPL_ASSERT_PARTS(
-                shortage >= beast::zero,
-                "ripple::detail::computePaymentComponents",
-                "excess non-negative");
-        };
     // Helper to reduce deltas when they collectively exceed a limit.
     // Order matters: we prefer to reduce interest first (most flexible),
     // then management fee, then principal (least flexible).
@@ -1101,19 +1084,6 @@ computePaymentComponents(
         takeFrom(deltas.managementFee, excess);
         takeFrom(deltas.principal, excess);
     };
-    // Helper to increase deltas when they collectively do not reach an
-    // expected value.
-    // Order matters: we prefer to increase interest first (most flexible),
-    // then management fee, then principal (least flexible).
-    auto addressShortage = [&giveTo](
-                               LoanDeltas& deltas,
-                               Number& shortage,
-                               LoanState const& current) {
-        giveTo(deltas.interestDueDelta, shortage, current.interestDue);
-        giveTo(
-            deltas.managementFeeDueDelta, shortage, current.managementFeeDue);
-        giveTo(deltas.principalDelta, shortage, current.principalOutstanding);
-    };
 
     // Check if deltas exceed the total outstanding value. This should never
     // happen due to earlier caps, but handle it defensively.
@@ -1145,19 +1115,12 @@ computePaymentComponents(
         addressExcess(deltas, excess);
         shortage = -excess;
     }
-    else if (shortage > beast::zero && totalOverpayment < beast::zero)
-    {
-        // If there's a shortage, and there's room in the loan itself, we can
-        // top up the parts to make the payment correct.
-        shortage = std::min(-totalOverpayment, shortage);
-        addressShortage(deltas, shortage, currentLedgerState);
-    }
 
     // At this point, shortage >= 0 means we're paying less than the full
     // periodic payment (due to rounding or component caps).
-    // shortage < 0 means mean we're trying to pay more than allowed (bug).
+    // shortage < 0 would mean we're trying to pay more than allowed (bug).
     XRPL_ASSERT_PARTS(
-        shortage == beast::zero,
+        shortage >= beast::zero,
         "ripple::detail::computePaymentComponents",
         "no shortage or excess");
 

src/xrpld/app/tx/detail/VaultWithdraw.cpp

@@ -1,4 +1,6 @@
 #include <xrpld/app/tx/detail/VaultWithdraw.h>
+//
+#include <xrpld/app/tx/detail/Payment.h>
 
 #include <xrpl/ledger/CredentialHelpers.h>
 #include <xrpl/ledger/View.h>
@@ -197,7 +199,7 @@ VaultWithdraw::doApply()
     assetsAvailable -= assetsWithdrawn;
     view().update(vault);
 
-    auto const& vaultAccount = vault->at(sfAccount);
+    AccountID const& vaultAccount = vault->at(sfAccount);
     // Transfer shares from depositor to vault.
     if (auto const ter = accountSend(
             view(),