Fix more problems introduced by 6adb2ec

- Renamed canSendToAccount to canWithdraw, because the semantics are
  a little different from a payment. Notably, if withdrawing to self,
  you can still include a destination tag.
- Simplified the interface to canWithdraw to just pass in the
  STTx.
- preflightDestinationAndTag is pretty pointless now, so removed it.

src/libxrpl/ledger/View.cpp

@@ -1340,26 +1340,6 @@ canAddHolding(ReadView const& view, Asset const& asset)
         asset.value());
 }
 
-[[nodiscard]] NotTEC
-preflightDestinationAndTag(
-    std::optional<AccountID> const& destination,
-    bool hasDestinationTag)
-{
-    if (destination)
-    {
-        if (*destination == beast::zero)
-        {
-            return temMALFORMED;
-        }
-    }
-    else if (hasDestinationTag)
-    {
-        return temMALFORMED;
-    }
-
-    return tesSUCCESS;
-}
-
 [[nodiscard]] TER
 checkDestinationAndTag(SLE::const_ref toSle, bool hasDestinationTag)
 {
@@ -1375,7 +1355,7 @@ checkDestinationAndTag(SLE::const_ref toSle, bool hasDestinationTag)
 }
 
 [[nodiscard]] TER
-canSendToAccount(
+canWithdraw(
     AccountID const& from,
     ReadView const& view,
     AccountID const& to,
@@ -1398,7 +1378,7 @@ canSendToAccount(
 }
 
 [[nodiscard]] TER
-canSendToAccount(
+canWithdraw(
     AccountID const& from,
     ReadView const& view,
     AccountID const& to,
@@ -1406,7 +1386,16 @@ canSendToAccount(
 {
     auto const toSle = view.read(keylet::account(to));
 
-    return canSendToAccount(from, view, to, toSle, hasDestinationTag);
+    return canWithdraw(from, view, to, toSle, hasDestinationTag);
+}
+
+[[nodiscard]] TER
+canWithdraw(ReadView const& view, STTx const& tx)
+{
+    auto const from = tx[sfAccount];
+    auto const to = tx[~sfDestination].value_or(from);
+
+    return canWithdraw(from, view, to, tx.isFieldPresent(sfDestinationTag));
 }
 
 [[nodiscard]] TER

src/test/app/LoanBroker_test.cpp

@@ -384,13 +384,6 @@ class LoanBroker_test : public beast::unit_test::suite
                 destination(AccountID{}),
                 ter(temMALFORMED));
 
-            // If a destination tag is specified, a destination must be
-            // specified, too
-            env(coverWithdraw(alice, keylet.key, vault.asset(1)),
-                dtag(123),
-                ter(temMALFORMED));
-            verifyCoverAmount(10);
-
             // Withdraw some of the cover amount
             env(coverWithdraw(alice, keylet.key, vault.asset(7)));
             env.close();

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

@@ -43,9 +43,13 @@ LoanBrokerCoverWithdraw::preflight(PreflightContext const& ctx)
     if (!isLegalNet(dstAmount))
         return temBAD_AMOUNT;
 
-    if (auto const ret = preflightDestinationAndTag(
-            ctx.tx[~sfDestination], ctx.tx.isFieldPresent(sfDestinationTag)))
-        return ret;
+    if (auto const destination = ctx.tx[~sfDestination])
+    {
+        if (*destination == beast::zero)
+        {
+            return temMALFORMED;
+        }
+    }
 
     return tesSUCCESS;
 }
@@ -85,11 +89,7 @@ LoanBrokerCoverWithdraw::preclaim(PreclaimContext const& ctx)
     AuthType authType = AuthType::Legacy;
     if (account != dstAcct)
     {
-        if (auto const ret = canSendToAccount(
-                account,
-                ctx.view,
-                dstAcct,
-                tx.isFieldPresent(sfDestinationTag)))
+        if (auto const ret = canWithdraw(ctx.view, tx))
             return ret;
 
         // The destination account must have consented to receive the asset by

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

@@ -42,9 +42,13 @@ VaultWithdraw::preflight(PreflightContext const& ctx)
     if (ctx.tx[sfAmount] <= beast::zero)
         return temBAD_AMOUNT;
 
-    if (auto const ret = preflightDestinationAndTag(
-            ctx.tx[~sfDestination], ctx.tx.isFieldPresent(sfDestinationTag)))
-        return ret;
+    if (auto const destination = ctx.tx[~sfDestination])
+    {
+        if (*destination == beast::zero)
+        {
+            return temMALFORMED;
+        }
+    }
 
     return tesSUCCESS;
 }
@@ -105,11 +109,7 @@ VaultWithdraw::preclaim(PreclaimContext const& ctx)
     auto const account = ctx.tx[sfAccount];
     auto const dstAcct = ctx.tx[~sfDestination].value_or(account);
 
-    if (auto const ret = canSendToAccount(
-            account,
-            ctx.view,
-            dstAcct,
-            ctx.tx.isFieldPresent(sfDestinationTag)))
+    if (auto const ret = canWithdraw(ctx.view, ctx.tx))
         return ret;
 
     // If sending to Account (i.e. not a transfer), we will also create (only